Administration and Deployment Guide

Administration and Deployment Guide
Oracle® Real Application Clusters
Administration and Deployment Guide
12c Release 2 (12.2)
E49900-12
July 2017
Oracle Real Application Clusters Administration and Deployment Guide, 12c Release 2 (12.2)
E49900-12
Copyright © 2009, 2017, Oracle and/or its affiliates. All rights reserved.
Primary Author: Richard Strohm
Contributing Authors: Janet Stern
Contributors: Troy Anthony, Lance Ashdown, Ram Avudaiappan, Prasad Bagal, Mark Bauer, Anand
Beldalker, Eric Belden, Gajanan Bhat, David Brower, George Claborn, Maria Colgan, Carol Colrain, Jonathan
Creighton, Rajesh Dasari, Steve Fogel, Richard Frank, GP Prabhaker Gongloor, Wei Hu, Yong Hu,
Dominique Jeunot, Sameer Joshi, Raj K. Kammend, Ankita Khandelwal, Sana Karam, Roland Knapp, Karen
Li, Barb Lundhild, Venkat Maddali, Bill Manry, John McHugh, Saar Maoz, Matthew Mckerley, Markus
Michalewicz, Anil Nair, Philip Newlan, Michael Nowak, Muthu Olagappan, Bharat Paliwal, Hanlin Qian,
Mark Ramacher, Sampath Ravindhran, Kevin Reardon, Kathy Rich, Dipak Saggi, Daniel Semler, Ara
Shakian, Cathy Shea, Khethavath P. Singh, Kesavan Srinivasan, Leo Tominna, Peter Wahl, Tak Wang,
Richard Wessman, Douglas Williams, Mike Zampiceni, Michael Zoll
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Contents
Preface ............................................................................................................................................................. xvii
Audience ....................................................................................................................................................
xvii
Documentation Accessibility ..................................................................................................................
xvii
Related Documents..................................................................................................................................
xviii
Conventions..............................................................................................................................................
xviii
Changes in This Release for Oracle Real Application Clusters Administration and
Deployment Guide ................................................................................................................................. xxi
Changes in Oracle Real Application Clusters 12c Release 2 (12.2)..................................................... xxi
Changes in Oracle Real Application Clusters 12c Release 1 (12.1)....................................................
xxii
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.2) ....................................
xxiii
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.1) .................................... xxiv
Deprecated Features......................................................................................................................
xxviii
Desupported Features ..................................................................................................................
xxviii
1 Introduction to Oracle RAC
Overview of Oracle RAC .........................................................................................................................
1-1
Overview of Installing Oracle RAC .......................................................................................................
1-3
Understanding Compatibility in Oracle RAC Environments....................................................
1-4
Oracle RAC Database Management Styles and Database Installation.....................................
1-4
Oracle RAC Database Management Styles and Database Creation .........................................
1-5
Overview of Extending an Oracle RAC Cluster ..........................................................................
1-6
Overview of Oracle Real Application Clusters One Node .................................................................
1-8
Overview of Oracle Clusterware for Oracle RAC................................................................................
1-9
Overview of Oracle Flex Clusters ................................................................................................ 1-10
Overview of Reader Nodes........................................................................................................... 1-10
Overview of Local Temporary Tablespaces ............................................................................... 1-11
Overview of Oracle RAC Architecture and Processing .................................................................... 1-17
Understanding Cluster-Aware Storage Solutions ..................................................................... 1-17
Oracle RAC and Network Connectivity ..................................................................................... 1-18
Overview of Using Dynamic Database Services to Connect to Oracle Databases ............... 1-19
iii
Overview of Virtual IP Addresses ............................................................................................... 1-19
Restricted Service Registration in Oracle RAC .......................................................................... 1-20
About Oracle RAC Software Components ................................................................................. 1-20
About Oracle RAC Background Processes ................................................................................. 1-21
Overview of Automatic Workload Management with Dynamic Database Services ................... 1-22
Overview of Server Pools and Policy-Managed Databases.............................................................. 1-24
Introduction to Server Pools ......................................................................................................... 1-25
Deploying Policy-Managed Databases ....................................................................................... 1-29
Managing Policy-Managed Databases ........................................................................................ 1-30
Policy-Based Cluster Management.............................................................................................. 1-31
Overview of Oracle Database Quality of Service Management ...................................................... 1-32
Overview of Hang Manager ................................................................................................................. 1-32
Overview of Oracle Multitenant with Oracle RAC ........................................................................... 1-33
Overview of Database In-Memory and Oracle RAC......................................................................... 1-34
Overview of Managing Oracle RAC Environments.......................................................................... 1-34
About Designing and Deploying Oracle RAC Environments................................................. 1-35
About Administrative Tools for Oracle RAC Environments................................................... 1-35
About Monitoring Oracle RAC Environments .......................................................................... 1-37
About Evaluating Performance in Oracle RAC Environments ............................................... 1-38
2 Administering Storage in Oracle RAC
Overview of Storage Management for Oracle RAC ............................................................................
2-2
Data File Access in Oracle RAC..............................................................................................................
2-2
NFS Server for Storage.............................................................................................................................
2-3
Redo Log File Storage in Oracle RAC....................................................................................................
2-3
Automatic Undo Management in Oracle RAC ....................................................................................
2-4
Oracle Automatic Storage Management with Oracle RAC ................................................................
2-4
Storage Management in Oracle RAC.............................................................................................
2-5
Modifying Disk Group Configurations for Oracle ASM............................................................
2-6
Oracle ASM Disk Group Management .........................................................................................
2-6
Configuring Preferred Mirror Read Disks in Extended Distance Clusters .............................
2-7
Converting Nonclustered Oracle ASM to Clustered Oracle ASM............................................
2-7
Administering Oracle ASM Instances with SRVCTL in Oracle RAC.......................................
2-7
3 Administering Database Instances and Cluster Databases
Overview of Oracle RAC Database Administration ...........................................................................
3-1
Tools for Administering Oracle RAC ............................................................................................
3-4
Starting and Stopping Instances and Oracle RAC Databases ............................................................
3-7
Starting One or More Instances and Oracle RAC Databases Using SRVCTL .........................
3-8
Stopping One or More Instances and Oracle RAC Databases Using SRVCTL .......................
3-9
Stopping All Databases and Instances Using CRSCTL ............................................................ 3-10
Starting and Stopping Individual Instances Using SQL*Plus ................................................. 3-10
Starting and Stopping PDBs in Oracle RAC ....................................................................................... 3-12
iv
Verifying That Instances are Running ................................................................................................. 3-13
Using SRVCTL to Verify That Instances are Running .............................................................. 3-13
Using SQL*Plus to Verify That Instances are Running ............................................................ 3-13
Terminating Sessions On a Specific Cluster Instance........................................................................ 3-14
Overview of Initialization Parameter Files in Oracle RAC .............................................................. 3-16
Setting SPFILE Parameter Values for Oracle RAC .................................................................... 3-17
Parameter File Search Order in Oracle RAC .............................................................................. 3-18
Backing Up the Server Parameter File......................................................................................... 3-18
Initialization Parameter Use in Oracle RAC ....................................................................................... 3-19
Parameters That Must Have Identical Settings on All Instances ............................................ 3-22
Parameters That Have Unique Settings on All Instances......................................................... 3-22
Parameters That Should Have Identical Settings on All Instances ......................................... 3-23
Converting an Administrator-Managed Database to a Policy-Managed Database...................... 3-24
Managing Memory Pressure for Database Servers ........................................................................... 3-26
Quiescing Oracle RAC Databases ........................................................................................................ 3-26
Administering Multiple Cluster Interconnects on Linux and UNIX Platforms ............................ 3-27
Use Cases for Setting the CLUSTER_INTERCONNECTS Parameter .................................... 3-28
Customizing How Oracle Clusterware Manages Oracle RAC Databases ..................................... 3-29
Advanced Oracle Enterprise Manager Administration .................................................................... 3-31
Using Oracle Enterprise Manager Cloud Control to Discover Nodes and Instances .......... 3-31
Other Oracle Enterprise Manager Capabilities.......................................................................... 3-32
Administering Jobs and Alerts in Oracle RAC .......................................................................... 3-32
4 Administering Oracle RAC One Node
Creating an Oracle RAC One Node Database ......................................................................................
4-1
Converting Databases ..............................................................................................................................
4-2
Converting a Database from Oracle RAC to Oracle RAC One Node.......................................
4-2
Converting a Database from Oracle RAC One Node to Oracle RAC.......................................
4-3
Online Database Relocation ....................................................................................................................
4-4
5 Workload Management with Dynamic Database Services
Connection Load Balancing ....................................................................................................................
5-1
Server-Side Load Balancing ............................................................................................................
5-2
Generic Database Clients.................................................................................................................
5-2
Client-Side Connection Configuration for Older Clients ...........................................................
5-3
Client-Side Load Balancing.............................................................................................................
5-4
Load Balancing Advisory ........................................................................................................................
5-5
Overview of the Load Balancing Advisory ..................................................................................
5-5
Configuring Your Environment to Use the Load Balancing Advisory ....................................
5-6
Load Balancing Advisory FAN Events ........................................................................................
5-6
Monitoring Load Balancing Advisory FAN Events....................................................................
5-7
Enabling Clients for Oracle RAC............................................................................................................
5-8
Overview of Oracle Integrated Clients and FAN ........................................................................
5-8
v
Enabling JDBC-Thin Clients for Fast Connection Failover ........................................................
5-9
Enabling JDBC Clients for Run-time Connection Load Balancing ......................................... 5-11
Configuring JDBC-Thin Clients for Application Continuity for Java .................................... 5-12
Configuring JDBC-Thin Clients for Transaction Guard ........................................................... 5-13
Enabling OCI Clients for Fast Connection Failover .................................................................. 5-14
Enabling OCI Clients for Run-time Connection Load Balancing............................................ 5-15
Configuring OCI Clients to use Transaction Guard.................................................................. 5-15
Enabling ODP.NET Clients to Receive FAN High Availability Events ................................. 5-16
Enabling ODP.NET Clients to Receive FAN Load Balancing Advisory Events................... 5-16
Configuring ODP.NET Clients to use Transaction Guard ....................................................... 5-17
Distributed Transaction Processing in Oracle RAC........................................................................... 5-17
Overview of XA Transactions and Oracle RAC......................................................................... 5-18
Using Global Transactions and XA Affinity for XA Transactions .......................................... 5-19
Using Services with XA Transactions on Oracle RAC.............................................................. 5-20
Configuring Services for XA Applications ................................................................................. 5-20
Relocating Services in Administrator-Managed Databases ..................................................... 5-21
Automatic Workload Repository ......................................................................................................... 5-21
Measuring Performance by Service Using the Automatic Workload Repository......................... 5-22
Automatic Workload Repository Service Thresholds and Alerts ................................................... 5-23
Example of Services and Thresholds Alerts .............................................................................. 5-24
Enable Service, Module, and Action Monitoring ...................................................................... 5-24
Using Oracle Services............................................................................................................................. 5-25
Service Deployment Options ................................................................................................................ 5-25
Service Usage in an Oracle RAC Database ................................................................................. 5-25
Service Characteristics ................................................................................................................... 5-27
Default Service Connections ......................................................................................................... 5-31
Restricted Service Registration..................................................................................................... 5-31
Administering Services .......................................................................................................................... 5-32
Overview of Service Administration........................................................................................... 5-32
Administering Services with Oracle Enterprise Manager........................................................ 5-34
Administering Services with SRVCTL ........................................................................................ 5-35
Global Services ........................................................................................................................................ 5-39
Service-Oriented Buffer Cache Access................................................................................................. 5-40
Connecting to a Service: An Example.................................................................................................. 5-40
6 Ensuring Application Continuity
Fast Application Notification..................................................................................................................
6-2
Overview of Fast Application Notification ..................................................................................
6-2
Managing Unplanned Outages ......................................................................................................
6-7
Managing Planned Maintenance ...................................................................................................
6-8
Fast Application Notification High Availability Events........................................................... 6-14
Subscription to High Availability Events ................................................................................... 6-16
Using Fast Application Notification Callouts ............................................................................ 6-16
vi
About Application Continuity.............................................................................................................. 6-17
Key Concepts for Application Continuity .................................................................................. 6-18
Application Continuity Operation and Usage ................................................................................... 6-19
How Application Continuity Works for Applications ............................................................. 6-20
Actions for Using Application Continuity ................................................................................. 6-22
Mutable Functions and Application Continuity........................................................................ 6-37
Administering Mutable Values .................................................................................................... 6-39
Session State Consistency.............................................................................................................. 6-40
Potential Side Effects of Application Continuity ............................................................................... 6-44
Restrictions and Other Considerations for Application Continuity ............................................... 6-44
Transaction Guard for Improving Client Failover............................................................................. 6-46
Transaction Guard Configuration Checklist .............................................................................. 6-47
Configuring Services for Transaction Guard ............................................................................. 6-47
Failing Over OCI Clients with TAF ..................................................................................................... 6-48
7 Configuring Recovery Manager and Archiving
Overview of Configuring RMAN for Oracle RAC ..............................................................................
7-1
Archiving Mode in Oracle RAC .............................................................................................................
7-1
Configuring the RMAN Snapshot Control File Location ...................................................................
7-2
Configuring RMAN to Automatically Backup the Control File and SPFILE ..................................
7-2
Crosschecking on Multiple Oracle RAC Nodes ...................................................................................
7-3
Configuring Channels for RMAN in Oracle RAC ...............................................................................
7-4
Configuring Channels to Use Automatic Load Balancing .........................................................
7-4
Configuring Channels to Use a Specific Node.............................................................................
7-4
Managing Archived Redo Logs Using RMAN in Oracle RAC..........................................................
7-4
Archived Redo Log File Conventions in Oracle RAC .........................................................................
7-5
RMAN Archiving Configuration Scenarios..........................................................................................
7-6
Oracle Automatic Storage Management and Cluster File System Archiving Scheme ..........
7-6
Noncluster File System Local Archiving Scheme ........................................................................
7-7
Monitoring the Archiver Processes ...................................................................................................... 7-10
8 Managing Backup and Recovery
RMAN Backup Scenario for Noncluster File System Backups ..........................................................
8-1
RMAN Restore Scenarios for Oracle RAC ............................................................................................
8-2
Restoring Backups from a Cluster File System ............................................................................
8-2
Restoring Backups from a Noncluster File System .....................................................................
Using RMAN or Oracle Enterprise Manager to Restore the Server Parameter File
8-3
(SPFILE)........................................................................................................................................
8-3
Instance Recovery in Oracle RAC ..........................................................................................................
8-3
Single Node Failure in Oracle RAC ...............................................................................................
8-4
Multiple-Node Failures in Oracle RAC.........................................................................................
8-4
Using RMAN to Create Backups in Oracle RAC.........................................................................
8-4
Node Affinity Awareness of Fast Connections ...........................................................................
8-6
vii
Deleting Archived Redo Logs after a Successful Backup...........................................................
8-6
Autolocation for Backup and Restore Commands......................................................................
8-6
Media Recovery in Oracle RAC..............................................................................................................
8-7
Parallel Recovery in Oracle RAC............................................................................................................
8-7
Parallel Recovery with RMAN .......................................................................................................
8-7
Disabling Parallel Recovery ............................................................................................................
8-8
Using a Fast Recovery Area in Oracle RAC..........................................................................................
8-8
9 Cloning Oracle RAC to Nodes in a New Cluster
Introduction to Cloning Oracle RAC .....................................................................................................
9-1
Preparing to Clone Oracle RAC..............................................................................................................
9-2
Deploying Oracle RAC Clone to Nodes in a Cluster...........................................................................
9-3
Locating and Viewing Log Files Generated During Cloning.............................................................
9-7
10 Using Cloning to Extend Oracle RAC to Nodes in the Same Cluster
About Adding Nodes Using Cloning in Oracle RAC Environments ............................................. 10-1
Cloning Local Oracle Homes on Linux and UNIX Systems............................................................. 10-1
Cloning Shared Oracle Homes on Linux and UNIX Systems.......................................................... 10-2
Cloning Oracle Homes on Windows Systems.................................................................................... 10-3
11 Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems
Adding Oracle RAC to Nodes with Oracle Clusterware Installed.................................................. 11-1
Adding Policy-Managed Oracle RAC Database Instances to Target Nodes......................... 11-3
Adding Administrator-Managed Oracle RAC Database Instances to Target Nodes .......... 11-4
Deleting Oracle RAC from a Cluster Node......................................................................................... 11-6
Deleting Instances from Oracle RAC Databases........................................................................ 11-6
Removing Oracle RAC .................................................................................................................. 11-9
Deleting Nodes from the Cluster ................................................................................................. 11-9
12 Adding and Deleting Oracle RAC from Nodes on Windows Systems
Adding Oracle RAC to Nodes with Oracle Clusterware Installed.................................................. 12-2
Adding Administrator-Managed Oracle RAC Database Instances to Target Nodes .......... 12-4
Deleting Oracle RAC from a Cluster Node......................................................................................... 12-6
Deleting Instances from Oracle RAC Databases........................................................................ 12-6
Removing Oracle RAC .................................................................................................................. 12-9
Deleting Nodes from the Cluster ................................................................................................. 12-9
13 Design and Deployment Techniques
Deploying Oracle RAC for High Availability .................................................................................... 13-1
About Designing a High Availability System............................................................................ 13-1
Best Practices for Deploying Oracle RAC in a High Availability Environment ................... 13-2
Consolidating Multiple Applications in a Database or Multiple Databases in a Cluster.... 13-4
Scalability of Oracle RAC .............................................................................................................. 13-5
viii
General Design Considerations for Oracle RAC................................................................................ 13-6
General Database Deployment Topics for Oracle RAC .................................................................... 13-6
Tablespace Use in Oracle RAC ..................................................................................................... 13-7
Object Creation and Performance in Oracle RAC .................................................................... 13-7
Node Addition and Deletion and the SYSAUX Tablespace in Oracle RAC.......................... 13-7
Distributed Transactions and Oracle RAC ................................................................................. 13-7
Deploying OLTP Applications in Oracle RAC .......................................................................... 13-8
Flexible Implementation with Cache Fusion.............................................................................. 13-8
Deploying Data Warehouse Applications with Oracle RAC................................................... 13-8
Data Security Considerations in Oracle RAC............................................................................. 13-9
14 Monitoring Performance
Overview of Monitoring and Tuning Oracle RAC Databases ......................................................... 14-1
Monitoring Oracle RAC and Oracle Clusterware ..................................................................... 14-1
Tuning Oracle RAC Databases..................................................................................................... 14-4
Verifying the Interconnect Settings for Oracle RAC.......................................................................... 14-5
Influencing Interconnect Processing .................................................................................................... 14-5
Performance Views in Oracle RAC ...................................................................................................... 14-6
Creating Oracle RAC Data Dictionary Views with CATCLUST.SQL ............................................ 14-6
Oracle RAC Performance Statistics ...................................................................................................... 14-7
Automatic Workload Repository in Oracle RAC Environments..................................................... 14-7
Active Session History Reports for Oracle RAC ................................................................................ 14-7
Overview of ASH Reports for Oracle RAC ................................................................................ 14-8
ASH Report for Oracle RAC: Top Cluster Events ..................................................................... 14-8
ASH Report for Oracle RAC: Top Remote Instance.................................................................. 14-8
Monitoring Oracle RAC Statistics and Wait Events .......................................................................... 14-8
Oracle RAC Statistics and Events in AWR and Statspack Reports......................................... 14-9
Oracle RAC Wait Events ............................................................................................................... 14-9
Monitoring Performance by Analyzing GCS and GES Statistics .......................................... 14-10
Analyzing Cache Fusion Transfer Impact Using GCS Statistics ........................................... 14-11
Analyzing Response Times Based on Wait Events ................................................................. 14-12
15 Converting Single-Instance Oracle Databases to Oracle RAC and Oracle
RAC One Node
Administrative Issues for Converting Databases to Oracle RAC.................................................... 15-1
Converting to Oracle RAC and Oracle RAC One Node Using DBCA ........................................... 15-2
Converting Oracle Database Installations to Oracle RAC Using DBCA................................ 15-3
Converting Single Instance on a Cluster to Oracle RAC One Node Using DBCA............... 15-4
Converting Single Instance on a Cluster to Oracle RAC Using DBCA .................................. 15-5
Preparing to Convert with rconfig and Oracle Enterprise Manager............................................... 15-9
Prerequisites for Converting to Oracle RAC Databases ........................................................... 15-9
Configuration Changes During Oracle RAC Conversion Using rconfig ............................... 15-9
Converting Databases to Oracle RAC Using rconfig or Oracle Enterprise Manager......... 15-10
ix
Converting Databases to Oracle RAC Using Oracle Enterprise Manager........................... 15-11
Converting Databases to Oracle RAC Using rconfig ...................................................................... 15-12
Example of rconfig XML Input Files for ConvertToRAC ............................................................... 15-13
Postconversion Steps............................................................................................................................ 15-15
A Server Control Utility Reference
SRVCTL Usage Information.................................................................................................................... A-1
Specifying Command Parameters as Keywords Instead of Single Letters ...................................... A-2
Character Set and Case Sensitivity of SRVCTL Object Values........................................................... A-3
Summary of Tasks for Which SRVCTL Is Used ................................................................................... A-4
Using SRVCTL Help................................................................................................................................. A-6
SRVCTL Privileges and Security ............................................................................................................ A-6
Additional SRVCTL Topics ..................................................................................................................... A-7
Deprecated SRVCTL Subprograms or Commands ............................................................................. A-7
Single Character Parameters for all SRVCTL Commands ......................................................... A-7
Miscellaneous SRVCTL Commands and Parameters ............................................................... A-15
SRVCTL Command Reference.............................................................................................................. A-16
srvctl add database......................................................................................................................... A-17
srvctl config database..................................................................................................................... A-21
srvctl convert database .................................................................................................................. A-22
srvctl disable database ................................................................................................................... A-23
srvctl disable diskgroup ................................................................................................................ A-24
srvctl add instance.......................................................................................................................... A-24
srvctl disable instance .................................................................................................................... A-25
srvctl add listener ........................................................................................................................... A-26
srvctl disable listener ..................................................................................................................... A-29
srvctl config listener ....................................................................................................................... A-29
srvctl add network ......................................................................................................................... A-30
srvctl config network ..................................................................................................................... A-31
srvctl add nodeapps....................................................................................................................... A-31
srvctl config nodeapps................................................................................................................... A-33
srvctl disable nodeapps ................................................................................................................. A-33
srvctl add ons .................................................................................................................................. A-34
srvctl config ons .............................................................................................................................. A-34
srvctl disable ons ............................................................................................................................ A-35
srvctl config qosmserver................................................................................................................ A-35
srvctl add scan ................................................................................................................................ A-35
srvctl config scan ............................................................................................................................ A-36
srvctl disable scan........................................................................................................................... A-37
srvctl add scan_listener ................................................................................................................. A-37
srvctl config scan_listener ............................................................................................................. A-38
srvctl disable scan_listener............................................................................................................ A-39
srvctl add service ............................................................................................................................ A-39
x
srvctl config service........................................................................................................................ A-46
srvctl disable service ...................................................................................................................... A-48
srvctl add srvpool........................................................................................................................... A-49
srvctl config srvpool....................................................................................................................... A-50
srvctl add vip .................................................................................................................................. A-51
srvctl config vip .............................................................................................................................. A-52
srvctl disable vip............................................................................................................................. A-52
srvctl config volume....................................................................................................................... A-53
srvctl disable volume ..................................................................................................................... A-54
srvctl downgrade database ........................................................................................................... A-55
enable ............................................................................................................................................... A-55
getenv ............................................................................................................................................... A-62
modify .............................................................................................................................................. A-65
predict .............................................................................................................................................. A-87
relocate ............................................................................................................................................. A-91
remove.............................................................................................................................................. A-98
setenv ............................................................................................................................................
A-107
start ................................................................................................................................................
A-110
status .............................................................................................................................................
A-120
stop ................................................................................................................................................
A-130
unsetenv........................................................................................................................................
A-142
update ...........................................................................................................................................
A-144
srvctl upgrade database..............................................................................................................
A-148
B Troubleshooting Oracle RAC
Where to Find Files for Analyzing Errors ............................................................................................. B-1
Managing Diagnostic Data in Oracle RAC ........................................................................................... B-2
Using Instance-Specific Alert Files in Oracle RAC .............................................................................. B-3
Enabling Tracing for Java-Based Tools and Utilities in Oracle RAC ................................................ B-3
Resolving Pending Shutdown Issues..................................................................................................... B-3
How to Determine If Oracle RAC Instances Are Using the Private Network................................. B-3
Database Fails to Start after Private NIC Failure ................................................................................. B-4
Glossary
Index
xi
xii
List of Tables
3-1
3-2
3-3
3-4
5-1
6-1
6-2
6-3
6-4
7-1
7-2
7-3
9-1
9-2
9-3
9-4
11-1
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-11
A-12
A-13
A-14
A-15
A-16
A-17
A-18
A-19
A-20
A-21
A-22
A-23
A-24
A-25
A-26
A-27
A-28
A-29
A-30
A-31
A-32
A-33
A-34
How SQL*Plus Commands Affect Instances........................................................................... 3-6
Descriptions of V$ACTIVE_INSTANCES Columns ........................................................... 3-14
Initialization Parameters Specific to Oracle RAC ................................................................ 3-19
Parameters That Should Have Identical Settings on All Instances.................................... 3-23
Load Balancing Advisory FAN Events.................................................................................... 5-7
Standard Tests for Some Common Application Servers....................................................... 6-6
Event Parameter Name-Value Pairs and Descriptions........................................................ 6-14
FAN Parameters and Matching Session Information.......................................................... 6-16
Example Treatment of Mutable Objects by Products During Replay............................... 6-37
Archived Redo Log File Name Format Parameters .............................................................. 7-5
UNIX/NFS Location Log Examples, Noncluster File System Local Archiving................. 7-9
UNIX/NFS Configuration for Shared Read Local Archiving Examples ........................... 7-9
clone.pl Script Parameters.......................................................................................................... 9-4
Environment Variables Passed to the clone.pl Script............................................................. 9-5
Cloning Parameters Passed to the clone.pl Script.................................................................. 9-5
Finding the Location of the Oracle Inventory Directory....................................................... 9-7
Variables in the DBCA Silent Mode Syntax.......................................................................... 11-5
String Restrictions for SRVCTL Object Names....................................................................... A-3
Deprecated Single-Character Parameters for SRVCTL Commands.................................... A-7
Deprecated Commands and Parameters for SRVCTL........................................................ A-16
Object Keywords and Abbreviations..................................................................................... A-17
srvctl add database Command Parameters.......................................................................... A-18
srvctl config database Command Parameters...................................................................... A-21
srvctl convert database Command Parameters.................................................................... A-22
srvctl disable database Parameters......................................................................................... A-23
srvctl disable diskgroup Parameters...................................................................................... A-24
srvctl add instance Command Parameters........................................................................... A-25
srvctl disable instance Parameters.......................................................................................... A-26
srvctl add listener Command Parameters............................................................................. A-27
srvctl disable listener Parameters........................................................................................... A-29
srvctl config listener Command Parameters......................................................................... A-29
srvctl add network Command Parameters........................................................................... A-30
srvctl add nodeapps Command Parameters......................................................................... A-32
srvctl disable nodeapps Parameters....................................................................................... A-33
srvctl add ons Command Parameters.................................................................................... A-34
srvctl add scan Command Parameters.................................................................................. A-35
srvctl config scan Command Parameters.............................................................................. A-36
srvctl add scan_listener Command Parameters................................................................... A-37
srvctl config scan_listener Command Parameters............................................................... A-38
srvctl add service Command Parameters.............................................................................. A-40
srvctl config service Command Parameters.......................................................................... A-47
srvctl disable service Parameters............................................................................................ A-48
srvctl add srvpool Command Parameters............................................................................. A-49
srvctl add vip Command Parameters.................................................................................... A-51
srvctl config vip Command Parameters................................................................................ A-52
srvctl disable vip Parameters.................................................................................................. A-52
srvctl config volume Command Parameters........................................................................ A-53
srvctl disable volume Parameters........................................................................................... A-54
srvctl downgrade database Parameters................................................................................. A-55
srvctl enable Summary............................................................................................................. A-56
srvctl enable database Parameters.......................................................................................... A-56
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srvctl enable diskgroup Parameters....................................................................................... A-57
srvctl enable instance Parameters........................................................................................... A-57
srvctl enable listener Parameters............................................................................................ A-58
srvctl enable nodeapps Parameters........................................................................................ A-59
srvctl enable service Parameters............................................................................................. A-60
srvctl enable vip Parameters................................................................................................... A-61
srvctl enable volume Parameters............................................................................................ A-62
srvctl getenv Summary............................................................................................................ A-63
srvctl getenv database Parameters......................................................................................... A-63
srvctl getenv listener Parameters............................................................................................ A-63
srvctl getenv nodeapps Parameters....................................................................................... A-64
srvctl getenv vip Parameters................................................................................................... A-65
srvctl modify Summary........................................................................................................... A-65
srvctl modify database Parameters........................................................................................ A-66
srvctl modify instance Command Parameters..................................................................... A-70
srvctl modify listener Parameters........................................................................................... A-71
srvctl modify network Parameters......................................................................................... A-72
srvctl modify nodeapps Parameters...................................................................................... A-75
srvctl modify ons Parameters.................................................................................................. A-76
srvctl modify scan Command Parameters............................................................................ A-77
srvctl modify scan_listener Command Parameters............................................................. A-78
srvctl modify service Parameters for Moving a Service...................................................... A-79
srvctl modify service Parameters for Changing to a Preferred Instance.......................... A-79
srvctl modify service Parameters for Changing Status of Multiple Instances................. A-80
srvctl modify service Parameters............................................................................................ A-81
srvctl modify srvpool Parameters.......................................................................................... A-85
srvctl modify vip Parameters.................................................................................................. A-86
srvctl predict Summary............................................................................................................ A-87
srvctl predict database Parameters......................................................................................... A-88
srvctl predict diskgroup Parameters...................................................................................... A-88
srvctl predict listener Parameters........................................................................................... A-89
srvctl predict network Parameters......................................................................................... A-89
srvctl predict scan Parameters................................................................................................ A-90
srvctl predict scan_listener Parameters................................................................................. A-90
srvctl predict service Parameters............................................................................................ A-91
srvctl predict vip Parameters.................................................................................................. A-91
srvctl relocate Command Summary....................................................................................... A-92
srvctl relocate database Parameters....................................................................................... A-92
srvctl relocate scan Parameters............................................................................................... A-94
srvctl relocate scan_listener Parameters................................................................................ A-94
srvctl relocate server Parameters............................................................................................ A-95
srvctl relocate service Command Parameters....................................................................... A-95
srvctl relocate vip Parameters................................................................................................. A-98
srvctl remove Summary........................................................................................................... A-98
srvctl remove database Command Parameters.................................................................... A-99
srvctl remove diskgroup Parameters................................................................................... A-100
srvctl remove instance Parameters....................................................................................... A-101
srvctl remove listener Parameters........................................................................................ A-101
srvctl remove network Parameters...................................................................................... A-102
srvctl remove nodeapps Parameters.................................................................................... A-103
srvctl remove ons Parameters............................................................................................... A-103
srvctl remove scan Command Parameters......................................................................... A-104
srvctl remove scan_listener Command Parameters.......................................................... A-104
srvctl remove service Parameters......................................................................................... A-105
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srvctl remove srvpool Parameters........................................................................................
srvctl remove vip Parameters...............................................................................................
srvctl remove volume Parameters........................................................................................
srvctl setenv Summary...........................................................................................................
srvctl setenv database Parameters........................................................................................
srvctl setenv listener Parameters..........................................................................................
srvctl setenv nodeapps Parameters......................................................................................
srvctl setenv vip Parameters.................................................................................................
srvctl start Summary..............................................................................................................
srvctl start database Parameters...........................................................................................
srvctl start diskgroup Parameters........................................................................................
srvctl start home Parameters.................................................................................................
srvctl start instance Parameters............................................................................................
srvctl start listener Command Parameters..........................................................................
srvctl start nodeapps Parameters.........................................................................................
srvctl start scan Parameters...................................................................................................
srvctl start scan_listener Parameters....................................................................................
srvctl start vip Parameters.....................................................................................................
srvctl start volume Parameters.............................................................................................
srvctl status Summary............................................................................................................
srvctl status database Parameters.........................................................................................
srvctl status diskgroup Parameters......................................................................................
srvctl status home Parameters..............................................................................................
srvctl status instance Parameters..........................................................................................
srvctl status listener Parameters...........................................................................................
srvctl status scan Parameters................................................................................................
srvctl status scan_listener Parameters.................................................................................
srvctl status server Parameters.............................................................................................
srvctl status service Parameters............................................................................................
srvctl status srvpool Parameters...........................................................................................
srvctl status vip Parameters..................................................................................................
srvctl status volume Parameters...........................................................................................
srvctl stop Summary..............................................................................................................
srvctl stop database Command Parameters.......................................................................
srvctl stop diskgroup Parameters.........................................................................................
srvctl stop home Parameters.................................................................................................
srvctl stop instance Command Parameters.........................................................................
srvctl stop listener Command Parameters..........................................................................
srvctl stop nodeapps Parameters..........................................................................................
srvctl stop scan Parameters...................................................................................................
srvctl stop scan_listener Parameters....................................................................................
srvctl stop service Command Parameters...........................................................................
srvctl stop vip Parameters.....................................................................................................
srvctl stop volume Parameters.............................................................................................
srvctl unsetenv Command Summary..................................................................................
srvctl unsetenv database Parameters...................................................................................
srvctl unsetenv listener Parameters.....................................................................................
srvctl unsetenv nodeapps Parameters.................................................................................
srvctl unsetenv vip Parameters.............................................................................................
srvctl update Command Summary......................................................................................
srvctl update gns Parameters................................................................................................
srvctl upgrade database Parameters....................................................................................
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xvi
Preface
TheOracle Real Application Clusters Administration and Deployment Guide describes the
Oracle Real Application Clusters (Oracle RAC) architecture and provides an overview
of this product, including Oracle Real Application Clusters One Node (Oracle RAC
One Node). This book also describes administrative and deployment topics for Oracle
RAC.
Information in this manual applies to Oracle RAC as it runs on all platforms unless
otherwise noted. In addition, the content of this manual supplements administrative
and deployment topics for noncluster Oracle databases that appear in other Oracle
documentation. Where necessary, this manual refers to platform-specific
documentation. This Preface includes these topics:
•
Audience
•
Documentation Accessibility
•
Related Documents
•
Conventions
Audience
The Oracle Real Application Clusters Administration and Deployment Guide is intended for
database administrators, network administrators, and system administrators who
perform the following tasks:
•
Install and configure an Oracle RAC database
•
Administer and manage Oracle RAC databases
•
Manage and troubleshoot clusters and networks that use Oracle RAC
Documentation Accessibility
For information about Oracle's commitment to accessibility, visit the Oracle
Accessibility Program website at http://www.oracle.com/pls/topic/lookup?
ctx=acc&id=docacc.
Access to Oracle Support
Oracle customers that have purchased support have access to electronic support
through My Oracle Support. For information, visit http://www.oracle.com/pls/
topic/lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?
ctx=acc&id=trs if you are hearing impaired.
xvii
Related Documents
This book, the Oracle Real Application Clusters Administration and Deployment Guide,
provides administration and application deployment information that is specific to
Oracle RAC. The discussions herein assume a knowledge of Oracle Clusterware.
For more information, see the Oracle resources listed in this section.
•
Oracle Database 2 Day + Real Application Clusters Guide
This task-oriented guide helps you understand the basic steps required to install,
configure, and administer Oracle Clusterware and Oracle RAC on a two-node
system using Red Hat Linux system.
•
Oracle Clusterware Administration and Deployment Guide
This is an essential companion book that describes Oracle Clusterware
components such as the voting disks and the Oracle Cluster Registry (OCR).
•
Platform-specific Oracle Clusterware and Oracle RAC installation guides
Each platform-specific Oracle Database installation media contains a copy of an
Oracle Clusterware and Oracle RAC platform-specific installation and
configuration guide in HTML and PDF formats. These installation books contain
the preinstallation, installation, and postinstallation information for the various
UNIX, Linux, and Windows platforms on which Oracle Clusterware and Oracle
RAC operate.
•
Oracle Database 2 Day DBA
•
Oracle Database Administrator's Guide
•
Oracle Database Net Services Administrator's Guide
•
Oracle Database Platform Guide for Microsoft Windows
•
Oracle Database Administrator's Reference for Linux and UNIX-Based Operating
Systems
•
Oracle Database 11g Administrator's Reference Release 1 (11.1) for UNIX Systems: AIX
Systems, HP-UX, Linux, and the Solaris Operating System (SPARC)
Note:
Additional information for this release may be available in the Oracle
Database 12c README or Release Notes. If these documents are available for
this release, then they are on your Oracle product installation media.
Database error messages descriptions are available online or by way of a Tahiti
documentation search.
Conventions
The following text conventions are used in this document:
xviii
Convention
Meaning
boldface
Boldface type indicates graphical user interface elements associated
with an action, or terms defined in text or the glossary.
italic
Italic type indicates book titles, emphasis, or placeholder variables for
which you supply particular values.
monospace
Monospace type indicates commands within a paragraph, URLs, code
in examples, text that appears on the screen, or text that you enter.
xix
Changes in This Release for Oracle Real
Application Clusters Administration and
Deployment Guide
This preface contains:
•
Changes in Oracle Real Application Clusters 12c Release 2 (12.2)
•
Changes in Oracle Real Application Clusters 12c Release 1 (12.1)
Changes in Oracle Real Application Clusters 12c Release 2 (12.2)
Following is a list of features that are new in the Oracle Real Application Clusters
Administration and Deployment Guide for Oracle Real Application Clusters 12c release 2
(12.2).
SCAN Listener Supports HTTP Protocol
Currently, when a connection request comes in, the SCAN listener load balances
among the handlers located on the same node. It then directly hands off the
connection to the least loaded handler on the node. With this release, the SCAN
listener is aware of the HTTP protocol so that it can redirect HTTP clients to the
appropriate handler, which can reside on nodes in the cluster other than the node on
which the SCAN listener resides.
IPv6 Support for Oracle Real Application Clusters on The Private Network
You can configure cluster nodes to use either IPv4- or IPv6-based IP addresses on a
private network, and you can use more than one private network for a cluster.
See Also: Oracle Clusterware Administration and Deployment Guide
Extend Oracle Database QoS Management to Fully Support AdministratorManaged Databases
In this release, full Oracle Database Quality of Service Management (Oracle Database
QoS Management) support is available by also supporting its Management mode.
Oracle supports schema consolidation within an administrator-managed Oracle RAC
database by adjusting the CPU shares of performance classes running in the database.
Additionally, database consolidation is supported by adjusting CPU counts per
databases hosted on the same physical servers.
As administrator-managed databases do not run in server pools, the ability to expand
or shrink the number of instances by changing the server pool size that is supported in
policy-managed database deployments is not available for administrator-managed
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databases. This deployment support is integrated into the Oracle Database QoS
Management pages in Oracle Enterprise Manager Cloud Control.
See Also: Oracle Database Quality of Service Management User's Guide
Oracle Real Application Clusters Reader Nodes
Oracle RAC Reader Nodes facilitate Oracle Flex Cluster architecture by allocating a set
of read/write instances running Online Transaction Processing (OLTP) workloads and
a set of read-only database instances across Hub Nodes and Leaf Nodes in the cluster.
In this architecture, updates to the read-write instances are immediately propagated to
the read-only instances on the Leaf Nodes, where they can be used for online
reporting or instantaneous queries.
See Also: Oracle Clusterware Administration and Deployment Guide
Server Weight-Based Node Eviction
Server weight-based node eviction acts as a tie-breaker mechanism in situations where
Oracle Clusterware must evict a particular node or a group of nodes from a cluster, in
which all nodes represent an equal choice for eviction. The server weight-based node
eviction mechanism helps to identify the node or the group of nodes to be evicted
based on additional information about the load on those servers. Two principle
mechanisms, a system-inherent automatic mechanism and a user input-based
mechanism, exist to provide respective guidance.
See Also: Oracle Clusterware Administration and Deployment Guide
Separation of Duty for Administering Oracle Real Application Clusters
Starting with Oracle Database 12c release 2 (12.2), Oracle Database provides support
for separation of duty best practices when administering Oracle Real Application
Clusters (Oracle RAC) by introducing the SYSRAC administrative privilege for the
clusterware agent. This feature removes the need to use the powerful SYSDBA
administrative privilege for Oracle RAC.
SYSRAC, like SYSDG, SYSBACKUP and SYSKM, helps enforce separation of duties
and reduce reliance on the use of SYSDBA on production systems. This administrative
privilege is the default mode for connecting to the database by the clusterware agent
on behalf of the Oracle RAC utilities, such as SRVCTL.
In-Memory FastStart
In-Memory FastStart optimizes the population of database objects in the In-Memory
column store by storing In-Memory compression units directly on disk.
See Also: Oracle Database In-Memory Guide
Changes in Oracle Real Application Clusters 12c Release 1 (12.1)
The following are changes in Oracle Real Application Clusters Administration and
Deployment Guide for Oracle Real Application Clusters (Oracle RAC) 12c:
xxii
•
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.2)
•
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.1)
•
Deprecated Features
•
Desupported Features
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.2)
The following features are new in this release:
•
In-Memory Column Store
The In-Memory Column Store is an optional area in the SGA that stores whole
tables, table partitions, and individual columns in a compressed columnar format.
The database uses special techniques, including SIMD vector processing, to scan
columnar data extremely rapidly. The In-Memory Column Store is a supplement
to, rather than a replacement for, the database buffer cache.
See Also:
Oracle Database Data Warehousing Guide for more information
•
In-Memory Transaction Manager
The In-Memory Transaction Manager is an independent engine that automatically
provides read consistency for transactions that apply changes to the In-Memory
Column Store. This engine is necessary because tables and partitions residing in
the In-Memory Column Store are stored in columnar format in memory and in
row-major format in the data files and database buffer cache.
See Also:
Oracle Database Concepts for more information
•
Rapid Home Provisioning
Rapid Home Provisioning enables you to deploy Oracle homes based on images
stored in a catalog of precreated software homes.
See Also:
Oracle Clusterware Administration and Deployment Guide for more information
•
Full Database In-Memory Caching
In this release you can cache an entire database in memory. Use this feature when
the buffer cache size of each instance is greater than the size of the whole
database. In Oracle RAC systems, for well-partitioned applications, you can use
this feature when the combined buffer caches of all database instances (with some
extra space to handle duplicate cached blocks between instances) is greater than
the database size.
xxiii
See Also:
Oracle Database Performance Tuning Guide for more information
•
Memory Guard Does Not Require Oracle Database QoS Management to be
Active
With this release, Memory Guard is enabled by default independent of whether
you use Oracle Database Quality of Service Management (Oracle Database QoS
Management). Memory Guard detects memory stress on a node and causes new
sessions to be directed to other instances until the existing workload drains and
frees memory. When free memory increases on the node, then services are
enabled again to automatically accept new connections.
Changes in Oracle Real Application Clusters 12c Release 1 (12.1.0.1)
The following features are new in this release:
•
Application Continuity
Before this release, application developers were required to deal explicitly with
outages of the underlying software, hardware, and communications layers if they
wanted to mask outages from end users.
In Oracle Database 10g, Fast Application Notification (FAN) quickly delivered
exception conditions to applications. However, neither FAN nor earlier Oracle
technology reported the outcome of the last transaction to the application, or
recovered the in-progress request from an application perspective. As a result,
outages were exposed leading to user inconvenience and lost revenue. Users
could unintentionally make duplicate purchases and submit multiple payments
for the same invoice. In the problematic cases, the administrator needed to reboot
the mid-tier to deal with the incoming problems this caused.
Application Continuity is an application-independent feature that attempts to
recover incomplete requests from an application perspective and masks many
system, communication, hardware failures, and storage outages from the end
user.
See Also:
•
–
Oracle Database Concepts for more information
–
Ensuring Application Continuity
Transaction Guard for Java
This feature exposes the new Application Continuity infrastructure to Java. It
provides support for:
xxiv
–
At-most-once transaction execution protocol, such as transaction idempotence
–
API for retrieving logical transaction ID (LTXID)
–
Attribute to get Connection or Session status
See Also:
Oracle Database JDBC Developer’s Guide for more information
•
Transaction Idempotence
This feature delivers a general purpose, application-independent infrastructure
that enables recovery of work from an application perspective and masks most
system, communication, and hardware failures from the user. Transaction
idempotence ensures that your transactions are executed on time and, at most,
once.
See Also:
Oracle Database Development Guide for more information
•
Oracle Flex Clusters
Large clusters consisting of, potentially, thousands of nodes, provide a platform
for Oracle RAC to support massive parallel query operations.
See Also:
Oracle Clusterware Administration and Deployment Guide for more information
about Oracle Flex Clusters
•
Shared Oracle ASM Password File in a Disk Group
This feature implements the infrastructure needed to address the bootstrapping
issues of storing an Oracle Automatic Storage Management (Oracle ASM) shared
password file in an Oracle ASM disk group.
See Also:
Oracle Automatic Storage Management Administrator's Guide
•
Global Data Services
Similar to the way Oracle RAC supports a database service and enables servicelevel workload management across database instances in a cluster, Global Data
Services provides Oracle RAC-like connect-time and run-time load balancing,
failover, and centralized service management for a set of replicated databases that
offer common services. The set of databases can include Oracle RAC and
nonclustered Oracle databases interconnected with Oracle Data Guard, Oracle
GoldenGate, or any other replication technology.
See Also:
Oracle Database Global Data Services Concepts and Administration Guide for more
information
•
Shared Grid Naming Service
xxv
One instance of Grid Naming Service (GNS) can service any number of clusters.
See Also:
Oracle Clusterware Administration and Deployment Guide for more information
•
What-If Command Evaluation for Oracle RAC
This feature of Oracle Clusterware improves resource management and
availability, through a mechanism that provides a policy response to a
hypothetical planned or unplanned event, without modifying the state of the
system.
In Oracle RAC, enhancements to SRVCTL aid you in determining the impact of
certain commands before you run them to determine the potential impact of the
command.
See Also:
•
–
"SRVCTL Usage Information" for a list of SRVCTL commands with WhatIf functionality
–
Oracle Clusterware Administration and Deployment Guide for a list of Oracle
Clusterware Control (CRSCTL) utility commands with similar
enhancements
Restricting Service Registration for Oracle RAC Deployments
This feature allows listener registration only from local IPs by default and
provides the ability to configure and dynamically update a set of IP addresses or
subnets from which registration requests are allowed by the listener.
See Also:
Oracle Database Net Services Administrator's Guide for more information
•
Restricting Service Registration with Valid Node Checking
This feature enables the network administrator to specify a list of nodes and
subnet information from which the Single Client Access Name (SCAN) listener
accepts registration. You can specify the nodes and subnets information using
SRVCTL, and SRVCTL stores the information in the SCAN listener resource
profile and this information is also written to the listener.ora file. Restricting
client access to a database makes Oracle RAC even more secure and less
vulnerable to security threads and attacks.
•
Pluggable Databases
Pluggable Databases enables an Oracle database to contain a portable collection of
schemas, schema objects, and nonschema objects that appears to an Oracle Net
client as a separate database. This self-contained collection is called a pluggable
database (PDB). A container database (CDB) is an Oracle database that includes
zero, one, or many user-created pluggable databases (PDBs). You can unplug a
PDB from a CDB and plug it into a different CDB.
xxvi
See Also:
Oracle Database Administrator’s Guide
•
Support of Oracle Home User on Windows
Starting with Oracle Database 12c, Oracle Database supports the use of an Oracle
home user, which you can specify at installation time. The Oracle home user is
associated with a Windows domain user. The Windows domain user should be a
low-privileged (non-Administrator) account to ensure that the Oracle home user
has a limited set of privileges, thus ensuring that the Oracle Database services
have only those privileges required to run Oracle products.
Windows Administrator user privileges are still required to perform Oracle
software maintenance tasks including installation, upgrade, patching, and so on.
Oracle Database administrative tools have been enhanced to ask for the password
of the Oracle home user, if needed. In Oracle RAC environments, you can store
the password for the Oracle home user in a secure wallet. If such a wallet exists,
then the Oracle Database administrative tools automatically use the password
from the wallet and do not require the user to enter the password for the Oracle
home user.
See Also:
Oracle Real Application Clusters Installation Guide for Microsoft Windows x64 (64Bit)
•
Cluster Resources for Oracle ACFS and Oracle ADVM
Oracle Clusterware resource support includes enhancements for Oracle homes
stored on Oracle Automatic Storage Management Cluster File System (Oracle
ACFS), Oracle ACFS General Purpose file systems for Grid homes, and Oracle
ASM Dynamic Volume Manager (Oracle ADVM) volumes. These resources, that
Oracle Clusterware manages, support automatic loading of Oracle ACFS, Oracle
ADVM and OKS drivers, disk group mounts, dynamic volume enablement, and
automatic Oracle ACFS file system mounts.
See Also:
Oracle Automatic Storage Management Administrator's Guide for more
information
•
Oracle Highly Available NFS
You can configure Oracle ACFS as a highly available, exported file system service.
This service uses Oracle ACFS' clusterwide data consistency and coherency, in
combination with virtual IP addresses, to provide failover capability for NFS
exports. By mounting the NFS export from this virtual IP address, a client can be
assured that, if one node of the cluster is available, then the NFS export will be
available.
xxvii
See Also:
Oracle Automatic Storage Management Administrator's Guide for more
information
•
Policy-Based Cluster Management and Administration
Oracle Grid Infrastructure allows running multiple applications in one cluster.
Using a policy-based approach, the workload introduced by these applications
can be allocated across the cluster using a policy. In addition, a policy set enables
different policies to be applied to the cluster over time as required. You can define
policy sets using a web-based interface or a command-line interface.
Hosting various workloads in the same cluster helps to consolidate the workloads
into a shared infrastructure that provides high availability and scalability. Using a
centralized policy-based approach allows for dynamic resource reallocation and
prioritization as the demand changes.
See Also:
Oracle Clusterware Administration and Deployment Guide for more information
•
Online Resource Attribute Modification
Oracle Clusterware manages hardware and software components for high
availability using a resource model. You use resource attributes to define how
Oracle Clusterware manages those resources. You can modify certain resource
attributes and implement those changes without having to restart the resource
using online resource attribute modification. You manage online resource
attribute modification with certain SRVCTL and CRSCTL commands.
Deprecated Features
Deprecation of single-letter SRVCTL CLI options
All SRVCTL commands have been enhanced to accept full-word options instead of the
single-letter options. All new SRVCTL command options added in this release support
full-word options, only, and do not have single-letter equivalents. The use of singleletter options with SRVCTL commands might be desupported in a future release.
Desupported Features
See Also:
Oracle Database Upgrade Guide for more information
•
Oracle Cluster File System for Windows
Oracle no longer supports Oracle Cluster File System (OCFS) on Windows.
•
Raw (block) storage devices for Oracle Database and related technologies
Oracle Database 12c release 1 (12.1) and its related grid technologies, such as
Oracle Clusterware, no longer support the direct use of raw or block storage
xxviii
devices. You must move existing files from raw or block devices to Oracle ASM
before you upgrade to Oracle Clusterware 12c release 1 (12.1).
xxix
1
Introduction to Oracle RAC
Provides an overview of Oracle Real Application Clusters (Oracle RAC) installation
and administration, and various components and functions.
This chapter includes the following topics:
•
Overview of Oracle RAC
•
Overview of Installing Oracle RAC
•
Overview of Oracle Real Application Clusters One Node
•
Overview of Oracle Clusterware for Oracle RAC
•
Overview of Oracle RAC Architecture and Processing
•
Overview of Automatic Workload Management with Dynamic Database Services
•
Overview of Server Pools and Policy-Managed Databases
•
Overview of Oracle Database Quality of Service Management
•
Overview of Hang Manager
•
Overview of Oracle Multitenant with Oracle RAC
•
Overview of Database In-Memory and Oracle RAC
•
Overview of Managing Oracle RAC Environments
Overview of Oracle RAC
Provides an introduction to Oracle RAC and its functionality.
Non-cluster Oracle databases have a one-to-one relationship between the Oracle
database and the instance. Oracle RAC environments, however, have a one-to-many
relationship between the database and instances. An Oracle RAC database can have
up to 100 instances,1 all of which access one database. All database instances must use
the same interconnect, which can also be used by Oracle Clusterware.
Oracle RAC databases differ architecturally from non-cluster Oracle databases in that
each Oracle RAC database instance also has:
1
•
At least one additional thread of redo for each instance
•
An instance-specific undo tablespace
With Oracle Database 10g release 2 (10.2) and later releases, Oracle Clusterware supports 100 nodes in an Oracle
Clusterware standard Cluster, with the option to run 100 database instances belonging to one production
database on these nodes.
Introduction to Oracle RAC 1-1
Overview of Oracle RAC
The combined processing power of the multiple servers can provide greater
throughput and Oracle RAC scalability than is available from a single server.
A cluster comprises multiple interconnected computers or servers that appear as if
they are one server to end users and applications. The Oracle RAC option with Oracle
Database enables you to cluster Oracle databases. Oracle RAC uses Oracle
Clusterware for the infrastructure to bind multiple servers so they operate as a single
system.
Oracle Clusterware is a portable cluster management solution that is integrated with
Oracle Database. Oracle Clusterware is a required component for using Oracle RAC
that provides the infrastructure necessary to run Oracle RAC. Oracle Clusterware also
manages resources, such as Virtual Internet Protocol (VIP) addresses, databases,
listeners, services, and so on. In addition, Oracle Clusterware enables both noncluster
Oracle databases and Oracle RAC databases to use the Oracle high-availability
infrastructure. Oracle Clusterware along with Oracle Automatic Storage Management
(Oracle ASM) (the two together comprise the Oracle Grid Infrastructure) enables you
to create a clustered pool of storage to be used by any combination of noncluster and
Oracle RAC databases.
Oracle Clusterware is the only clusterware that you need for most platforms on which
Oracle RAC operates. If your database applications require vendor clusterware, then
you can use such clusterware in conjunction with Oracle Clusterware if that vendor
clusterware is certified for Oracle RAC.
Figure 1-1 shows how Oracle RAC is the Oracle Database option that provides a single
system image for multiple servers to access one Oracle database. In Oracle RAC, each
Oracle instance must run on a separate server.
Figure 1-1
Oracle Database with Oracle RAC Architecture
Application / Web Servers
HR
HR
HR
Sales
Sales
Sales
Call Center
Call Center
Call Center
Oracle Net Services Client Access
HR Service
Sales Service
Node 1
Instance 1
Call Center Service
Node 2
hb
hb
Instance 2
Node 3
hb
hb
Instance 3
RAC
Database
Heartbeat
1-2 Oracle Real Application Clusters Administration and Deployment Guide
hb
Overview of Installing Oracle RAC
Traditionally, an Oracle RAC environment is located in one data center. However, you
can configure Oracle RAC on an Oracle Extended Cluster, which is an architecture
that provides extremely fast recovery from a site failure and allows for all nodes, at all
sites, to actively process transactions as part of a single database cluster. In an
extended cluster, the nodes in the cluster are typically dispersed, geographically, such
as between two fire cells, between two rooms or buildings, or between two different
data centers or cities. For availability reasons, the data must be located at both sites,
thus requiring the implementation of disk mirroring technology for storage.
If you choose to implement this architecture, you must assess whether this architecture
is a good solution for your business, especially considering distance, latency, and the
degree of protection it provides. Oracle RAC on extended clusters provides higher
availability than is possible with local Oracle RAC configurations, but an extended
cluster may not fulfill all of the disaster-recovery requirements of your organization. A
feasible separation provides great protection for some disasters (for example, local
power outage or server room flooding) but it cannot provide protection against all
types of outages. For comprehensive protection against disasters—including
protection against corruptions and regional disasters—Oracle recommends the use of
Oracle Data Guard with Oracle RAC, as described in the Oracle Data Guard Concepts
and Administration and on the Maximum Availability Architecture (MAA) Web site.
Oracle RAC is a unique technology that provides high availability and scalability for
all application types. The Oracle RAC infrastructure is also a key component for
implementing the Oracle enterprise grid computing architecture. Having multiple
instances access a single database prevents the server from being a single point of
failure. Oracle RAC enables you to combine smaller commodity servers into a cluster
to create scalable environments that support mission critical business applications.
Applications that you deploy on Oracle RAC databases can operate without code
changes.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Grid Infrastructure Installation and Upgrade Guide
Oracle Data Guard Concepts and Administration
Maximum Availability Architecture (MAA)
Overview of Installing Oracle RAC
Install Oracle Grid Infrastructure and Oracle Database software using Oracle
Universal Installer, and create your database with Database Configuration Assistant
(DBCA).
This ensures that your Oracle RAC environment has the optimal network
configuration, database structure, and parameter settings for the environment that you
selected.
Alternatively, you can install Oracle RAC using Rapid Home Provisioning, which
offers all of the advantages of Oracle Universal Installer and DBCA previously
specified. In addition, Rapid Home Provisioning allows for standardization and
automation.
This section introduces the installation processes for Oracle RAC under the following
topics:
•
Understanding Compatibility in Oracle RAC Environments
Introduction to Oracle RAC 1-3
Overview of Installing Oracle RAC
•
Oracle RAC Database Management Styles and Database Installation
•
Oracle RAC Database Management Styles and Database Creation
•
Overview of Extending an Oracle RAC Cluster
Note:
You must first install Oracle Grid Infrastructure before installing Oracle RAC.
Related Topics:
Oracle Real Application Clusters Installation Guide
Oracle Grid Infrastructure Installation and Upgrade Guide
Understanding Compatibility in Oracle RAC Environments
To run Oracle RAC in configurations with different versions of Oracle Database in the
same cluster, you must first install Oracle Grid Infrastructure, which must be the same
version, or higher, as the highest version of Oracle Database that you want to deploy
in this cluster. For example, to run an Oracle RAC 11g release 2 (11.2) database and an
Oracle RAC 12c database in the same cluster, you must install Oracle Grid
Infrastructure 12c. Contact My Oracle Support for more information about version
compatibility in Oracle RAC environments.
Note:
Oracle does not support deploying an Oracle9i cluster in an Oracle Grid
Infrastructure 12c environment.
Oracle RAC Database Management Styles and Database Installation
Before installing the Oracle RAC database software and creating respective databases,
decide on the management style you want to apply to the Oracle RAC databases, as
described in "Overview of Server Pools and Policy-Managed Databases".
The management style you choose impacts the software deployment and database
creation. If you choose the administrator-managed database deployment model, using
a per-node installation of software, then it is sufficient to deploy the Oracle Database
software (the database home) on only those nodes on which you plan to run Oracle
Database.
If you choose the policy-managed deployment model, using a per-node installation of
software, then you must deploy the software on all nodes in the cluster, because the
dynamic allocation of servers to server pools, in principle, does not predict on which
server a database instance can potentially run. To avoid instance startup failures on
servers that do not host the respective database home, Oracle strongly recommends
that you deploy the database software on all nodes in the cluster. When you use a
shared Oracle Database home, accessibility to this home from all nodes in the cluster is
assumed and the setup needs to ensure that the respective file system is mounted on
all servers, as required.
Oracle Universal Installer will only allow you to deploy an Oracle Database home
across nodes in the cluster if you previously installed and configured Oracle Grid
Infrastructure for the cluster. If Oracle Universal Installer does not give you an option
1-4 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Installing Oracle RAC
to deploy the database home across all nodes in the cluster, then check the
prerequisite, as stated, by Oracle Universal Installer.
During installation, you can choose to create a database during the database home
installation. Oracle Universal Installer runs DBCA to create your Oracle RAC database
according to the options that you select.
See Also:
"Oracle RAC Database Management Styles and Database Creation" for more
information if you choose this option
Note:
Before you create a database, a default listener must be running in the Oracle
Grid Infrastructure home. If a default listener is not present in the Oracle Grid
Infrastructure home, then DBCA returns an error instructing you to run
NETCA from the Oracle Grid Infrastructure home to create a default listener.
The Oracle RAC software is distributed as part of the Oracle Database installation
media. By default, the Oracle Database software installation process installs the Oracle
RAC option when it recognizes that you are performing the installation on a cluster.
Oracle Universal Installer installs Oracle RAC into a directory structure referred to as
the Oracle home, which is separate from the Oracle home directory for other Oracle
software running on the system. Because Oracle Universal Installer is cluster aware, it
installs the Oracle RAC software on all of the nodes that you defined to be part of the
cluster.
Related Topics:
Overview of Server Pools and Policy-Managed Databases
Server pools are the basis for policy-managed databases.
Oracle RAC Database Management Styles and Database Creation
Part of Oracle Database deployment is the creation of the database.
Oracle Database Net Services Administrator's Guide
Oracle RAC Database Management Styles and Database Creation
Part of Oracle Database deployment is the creation of the database.
You can choose to create a database as part of the database software deployment, as
described in "Oracle RAC Database Management Styles and Database Installation", or
you can choose to only deploy the database software, first, and then, subsequently,
create any database that is meant to run out of the newly created Oracle home by
using DBCA. In either case, you must consider the management style that you plan to
use for the Oracle RAC databases.
For administrator-managed databases, you must ensure that the database software is
deployed on the nodes on which you plan to run the respective database instances.
You must also ensure that these nodes have access to the storage in which you want to
store the database files. Oracle recommends that you select Oracle ASM during
database installation to simplify storage management. Oracle ASM automatically
manages the storage of all database files within disk groups. If you plan to use Oracle
Introduction to Oracle RAC 1-5
Overview of Installing Oracle RAC
Database Standard Edition to create an Oracle RAC database, then you must use
Oracle ASM to store all of the database files.
For policy-managed databases, you must ensure that the database software is
deployed on all nodes on which database instances can potentially run, given your
active server pool setup. You must also ensure that these nodes have access to the
storage in which you want to store the database files. Oracle recommends using Oracle
ASM, as previously described for administrator-managed databases.
Server pools are a feature of Oracle Grid Infrastructure (specifically Oracle
Clusterware). There are different ways you can set up server pools on the Oracle
Clusterware level, and Oracle recommends you create server pools for database
management before you create the respective databases. DBCA, however, will present
you with a choice of either using precreated server pools or creating a new server pool,
when you are creating a policy-managed database. Whether you can create a new
server pool during database creation depends on the server pool configuration that is
active at the time.
By default, DBCA creates one service for your Oracle RAC installation. This is the
default database service and should not be used for user connectivity. The default
database service is typically identified using the combination of the DB_NAME and
DB_DOMAIN initialization parameters: db_name.db_domain. The default service is
available on all instances in an Oracle RAC environment, unless the database is in
restricted mode.
Note:
Oracle recommends that you reserve the default database service for
maintenance operations and create dynamic database services for user or
application connectivity as a post-database-creation step, using either SRVCTL
or Oracle Enterprise Manager. DBCA no longer offers a dynamic database
service creation option for Oracle RAC databases. For Oracle RAC One Node
databases, you must create at least one dynamic database service.
Related Topics:
Oracle RAC Database Management Styles and Database Installation
Oracle Clusterware Administration and Deployment Guide
Overview of Extending an Oracle RAC Cluster
If you want to extend the Oracle RAC cluster (also known as cloning) and add nodes
to the existing environment after your initial deployment, then you must to do this on
multiple layers, considering the management style that you currently use in the
cluster.
Oracle provides various means of extending an Oracle RAC cluster. In principle, you
can choose from the following approaches to extend the current environment:
•
Rapid Home Provisioning to provision new Oracle RAC databases and other
software
•
Cloning using cloning scripts
•
Adding nodes using the addnode.sh (addnode.bat on Windows) script
1-6 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Installing Oracle RAC
Both approaches are applicable, regardless of how you initially deployed the
environment. Both approaches copy the required Oracle software on to the node that
you plan to add to the cluster. Software that gets copied to the node includes the
Oracle Grid Infrastructure software and the Oracle database homes.
For Oracle database homes, you must consider the management style deployed in the
cluster. For administrator-managed databases, you must ensure that the database
software is deployed on the nodes on which you plan to run the respective database
instances. For policy-managed databases, you must ensure that the database software
is deployed on all nodes on which database instances can potentially run, given your
active server pool setup. In either case, you must first deploy Oracle Grid
Infrastructure on all nodes that are meant to be part of the cluster.
Note:
Oracle cloning is not a replacement for cloning using Oracle Enterprise
Manager as part of the Provisioning Pack. When you clone Oracle RAC using
Oracle Enterprise Manager, the provisioning process includes a series of steps
where details about the home you want to capture, the location to which you
want to deploy, and various other parameters are collected.
For new installations or if you install only one Oracle RAC database, use the
traditional automated and interactive installation methods, such as Oracle Universal
Installer, Rapid Home Provisioning, or the Provisioning Pack feature of Oracle
Enterprise Manager. If your goal is to add or delete Oracle RAC from nodes in the
cluster, you can use the procedures detailed in "Adding and Deleting Oracle RAC
from Nodes on Linux and UNIX Systems".
The cloning process assumes that you successfully installed an Oracle Clusterware
home and an Oracle home with Oracle RAC on at least one node. In addition, all root
scripts must have run successfully on the node from which you are extending your
cluster database.
Related Topics:
Cloning Oracle RAC to Nodes in a New Cluster
This chapter describes how to clone Oracle Real Application Clusters
(Oracle RAC) database homes on Linux and UNIX systems to nodes in a
new cluster.
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems
Extend an existing Oracle Real Application Clusters (Oracle RAC) home
to other nodes and instances in the cluster, and delete Oracle RAC from
nodes and instances in the cluster.
Adding and Deleting Oracle RAC from Nodes on Windows Systems
Oracle Clusterware Administration and Deployment Guide
Introduction to Oracle RAC 1-7
Overview of Oracle Real Application Clusters One Node
See Also:
•
Oracle Clusterware Administration and Deployment Guide for more
information about Rapid Home Provisioning
•
Oracle Enterprise Manager online help system for more information
about the Provisioning Pack
Overview of Oracle Real Application Clusters One Node
Oracle Real Application Clusters One Node (Oracle RAC One Node) is an option to
Oracle Database Enterprise Edition available since Oracle Database 11g release 2 (11.2).
Oracle RAC One Node is a single instance of an Oracle RAC-enabled database
running on one node in the cluster, only, under normal operations. This option adds to
the flexibility that Oracle offers for database consolidation while reducing
management overhead by providing a standard deployment for Oracle databases in
the enterprise. Oracle RAC One Node database requires Oracle Grid Infrastructure
and, therefore, requires the same hardware setup as an Oracle RAC database.
Oracle supports Oracle RAC One Node on all platforms on which Oracle RAC is
certified. Similar to Oracle RAC, Oracle RAC One Node is certified on Oracle Virtual
Machine (Oracle VM). Using Oracle RAC or Oracle RAC One Node with Oracle VM
increases the benefits of Oracle VM with the high availability and scalability of Oracle
RAC.
With Oracle RAC One Node, there is no limit to server scalability and, if applications
grow to require more resources than a single node can supply, then you can upgrade
your applications online to Oracle RAC. If the node that is running Oracle RAC One
Node becomes overloaded, then you can relocate the instance to another node in the
cluster. With Oracle RAC One Node you can use the Online Database Relocation
feature to relocate the database instance with no downtime for application users.
Alternatively, you can limit the CPU consumption of individual database instances
per server within the cluster using Resource Manager Instance Caging and
dynamically change this limit, if necessary, depending on the demand scenario.
Using the Single Client Access Name (SCAN) to connect to the database, clients can
locate the service independently of the node on which it is running. Relocating an
Oracle RAC One Node instance is therefore mostly transparent to the client,
depending on the client connection. Oracle recommends to use either Application
Continuity and Oracle Fast Application Notification or Transparent Application
Failover to minimize the impact of a relocation on the client.
Oracle RAC One Node databases are administered slightly differently from Oracle
RAC or non-cluster databases. For administrator-managed Oracle RAC One Node
databases, you must monitor the candidate node list and make sure a server is always
available for failover, if possible. Candidate servers reside in the Generic server pool
and the database and its services will fail over to one of those servers.
For policy-managed Oracle RAC One Node databases, you must ensure that the server
pools are configured such that a server will be available for the database to fail over to
in case its current node becomes unavailable. In this case, the destination node for
online database relocation must be located in the server pool in which the database is
located. Alternatively, you can use a server pool of size 1 (one server in the server
pool), setting the minimum size to 1 and the importance high enough in relation to all
other server pools used in the cluster, to ensure that, upon failure of the one server
1-8 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle Clusterware for Oracle RAC
used in the server pool, a new server from another server pool or the Free server pool
is relocated into the server pool, as required.
Note:
•
Oracle RAC One Node supports Transaction Guard and Application
Continuity for failing clients over.
•
To prepare for all failure possibilities, you must add at least one Dynamic
Database Service (Oracle Clusterware-managed database service) to an
Oracle RAC One Node database.
Related Topics:
Oracle Real Application Clusters Installation Guide for Linux and UNIX
Transaction Guard for Improving Client Failover
Transaction Guard prevents a transaction being replayed by Application
Continuity from being applied more than once.
Overview of Oracle Clusterware for Oracle RAC
Oracle Clusterware provides a complete, integrated clusterware management solution
on all Oracle Database platforms.
This clusterware functionality provides all of the features required to manage your
cluster database including node membership, group services, global resource
management, and high availability functions.
You can install Oracle Clusterware independently or as a prerequisite to the Oracle
RAC installation process. Oracle Database features, such as services, use the
underlying Oracle Clusterware mechanisms to provide advanced capabilities. Oracle
Database also continues to support select third-party clusterware products on
specified platforms.
Oracle Clusterware is designed for, and tightly integrated with, Oracle RAC. You can
use Oracle Clusterware to manage high-availability operations in a cluster. When you
create an Oracle RAC database using any of the management tools, the database is
registered with and managed by Oracle Clusterware, along with the other required
components such as the VIP address, the Single Client Access Name (SCAN) (which
includes the SCAN VIPs and the SCAN listener), Oracle Notification Service, and the
Oracle Net listeners. These resources are automatically started when the node starts
and automatically restart if they fail. The Oracle Clusterware daemons run on each
node.
Anything that Oracle Clusterware manages is known as a CRS resource. A CRS
resource can be a database, an instance, a service, a listener, a VIP address, or an
application process. Oracle Clusterware manages CRS resources based on the
resource's configuration information that is stored in the Oracle Cluster Registry
(OCR). You can use SRVCTL commands to administer any Oracle-defined CRS
resources. Oracle Clusterware provides the framework that enables you to create CRS
resources to manage any process running on servers in the cluster which are not
predefined by Oracle. Oracle Clusterware stores the information that describes the
configuration of these components in OCR that you can administer.
Introduction to Oracle RAC 1-9
Overview of Oracle Clusterware for Oracle RAC
Another advantage with Oracle Flex Clusters is that you can convert Hub Nodes to
Leaf Nodes and vice versa, and you can convert a Leaf Node to a Hub Node with no
downtime.
This section includes the following topics:
•
Overview of Oracle Flex Clusters
•
Overview of Reader Nodes
•
Overview of Local Temporary Tablespaces
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Clusterware Administration and Deployment Guide
Overview of Oracle Flex Clusters
Oracle Flex Clusters provide a platform for a variety of applications, including Oracle
RAC databases with large numbers of nodes.
Oracle Flex Clusters also provide a platform for other service deployments that
require coordination and automation for high availability.
All nodes in an Oracle Flex Cluster belong to a single Oracle Grid Infrastructure
cluster. This architecture centralizes policy decisions for deployment of resources
based on application needs, to account for various service levels, loads, failure
responses, and recovery.
Oracle Flex Clusters contain two types of nodes arranged in a hub and spoke
architecture: Hub Nodes and Leaf Nodes. The number of Hub Nodes in an Oracle
Flex Cluster can be as many as 64. The number of Leaf Nodes can be many more. Hub
Nodes and Leaf Nodes can host different types of applications.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Overview of Reader Nodes
Reader nodes are instances of an Oracle RAC database that run on Leaf Nodes in an
Oracle Flex Cluster, a feature that was unavailable in previous Oracle Clusterware
releases.
An advantage of using reader nodes is that these instances are not affected if you need
to reconfigure a Hub Node. Parallel query jobs running on reader nodes are not
subject to the brownout times that can occur when you reconfigure a Hub Node, and
can continue to service clients that are connected to the reader nodes, as long as the
Hub Node to which it is connected is not evicted from the cluster. You can scale up to
64 reader nodes per Hub Node, and reader nodes can utilize massive parallel query to
speed up operations on large data sets.
Database instances running on reader nodes have different characteristics than
database instances running on Hub Nodes. Hub Node instances are similar to
previous versions of Oracle RAC database instances, whereas instances running on
reader nodes have the following notable differences:
•
Database instances run in read-only mode.
1-10 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle Clusterware for Oracle RAC
•
Database instances are unaffected if you reconfigure Hub Node clusterware.
Database instances running on reader nodes are not subject to the brownout times
and can continue to service the clients connected to the reader nodes, as long as
the Hub Node to which it is connected is not evicted from the cluster. Using
reader nodes, you can scale up to 64 reader nodes per hub.
•
Because database instances running on the reader nodes are read only, you will
receive an error if you attempt any DDL or DML operations.
You can create services to direct queries to read-only instances running on reader
nodes. These services can use parallel query to further speed up performance. Oracle
recommends that you size the memory in these reader nodes as high as possible so
that parallel queries can use the memory for best performance.
Overview of Local Temporary Tablespaces
To improve I/O operations, Oracle introduces a local temporary tablespace in Oracle
Database 12c release 2 (12.2), so that spill-overs are written to the local disks on the
reader nodes.
It is still possible for SQL operations, such as hash aggregation, sort, hash join, creation
of cursor-duration temporary tables for the WITH clause, and star transformation to
spill over to disk (specifically to the global temporary tablespace on shared disks).
Management of the local temporary tablespace is similar to that of the existing
temporary tablespace.
Local temporary tablespaces improve temporary tablespace management in read-only
instances by:
•
Storing temp files in reader node private storage to take advantage of the I/O
benefits of local storage.
•
Avoiding expensive cross-instance temporary tablespace management.
•
Increased addressability of temporary tablespace.
•
Improving instance warm-up performance by eliminating on-disk space metadata
management.
Note: You cannot use local temporary tablespaces to store database objects,
such as tables or indexes. This same restriction is also true for space for Oracle
global temporary tables.
This section includes the following topics:
•
Parallel Execution Support for Cursor-Duration Temporary Tablespaces
•
Local Temporary Tablespace Organization
•
Temporary Tablespace Hierarchy
•
Local Temporary Tablespace Features
•
Metadata Management of Local Temporary Files
•
DDL Support for Local Temporary Tablespaces
•
Local Temporary Tablespaces for Users
Introduction to Oracle RAC 1-11
Overview of Oracle Clusterware for Oracle RAC
•
Atomicity Requirement for Commands
•
Local Temporary Tablespace and Dictionary Views
Parallel Execution Support for Cursor-Duration Temporary Tablespaces
The temporary tablespaces created for the WITH clause and star transformation exist in
the temporary tablespace on the shared disk. A set of parallel query child processes
load intermediate query results into these temporary tablespaces, which are then read
later by a different set of child processes. There is no restriction on how these child
processes reading these results are allocated, as any parallel query child process on
any instance can read the temporary tablespaces residing on the shared disk.
For read-write and read-only instance architecture, as the parallel query child
processes load intermediate results to the local temporary tablespaces of these
instances, the parallel query child processes belonging to the instance where the
intermediate results are stored share affinity with the reads for the intermediate
results and can thus read them.
Local Temporary Tablespace Organization
You can create local temporary tablespace using the {FOR_RIM | FOR ALL}
extension, as follows:
CREATE LOCAL TEMPORARY TABLESPACE FOR RIM local_temp_ts_for_rim TEMPFILE\
'/u01/app/oracle/database/12.2.0.1/dbs/temp_file_rim'\
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M AUTOEXTEND ON;
•
Creation of a local temporary tablespace results in the creation of local temporary
files on every instance and not a single file, as is currently true for shared global
temporary tablespaces.
•
You can create local temporary tablespaces for both read-only and read-write
instances. The LOCAL FOR RIM option creates a local temporary tablespace
whose files reside on local disks for read-only instances. The LOCAL FOR ALL
option creates a local temporary tablespace whose files reside on local disks for
both read-write and read-only instances. For example:
CREATE LOCAL TEMPORARY TABLESPACE FOR ALL temp_ts_for_all TEMPFILE\
‘/u01/app/oracle/database/12.2.0.1/dbs/temp_file_all’\
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M AUTOEXTEND ON;
Temporary Tablespace Hierarchy
When you define local temporary tablespace and shared (existing) temporary
tablespace, there is a hierarchy in which they are used. To understand the hierarchy,
remember that there can be multiple shared temporary tablespaces in a database, such
the default shared temporary tablespace for the database and multiple temporary
tablespaces assigned to individual users. If a user has a shared temporary tablespace
assigned, then that tablespace is used first, otherwise the database default temporary
tablespace is used.
Once a tablespace has been selected for spilling during query processing, there is no
switching to another tablespace. For example, if a user has a shared temporary
tablespace assigned and during spilling it runs out of space, then there is no switching
to an alternative tablespace. The spilling, in that case, will result in an error.
Additionally, remember that shared temporary tablespaces are shared among
instances.
1-12 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle Clusterware for Oracle RAC
The allocation of temporary space for spilling to a local temporary tablespace differs
between read-only and read-write instances. For read-only instances, the following is
the priority of selecting which temporary location to use for spills:
1.
Allocate from a user's local temporary tablespace.
2.
Allocate from the database default local temporary tablespace.
3.
Allocate from a user's temporary tablespace.
4.
Allocate from the database default temporary tablespace.
Note: If there is no local temporary tablespace in the database, then read-only
instances will spill to shared temporary tablespace.
For read-write instances, the priority of allocation differs from the preceding allocation
order, as shared temporary tablespaces are given priority, as follows:
1.
Allocate from a user’s shared temporary tablespace.
2.
Allocate from a user’s local temporary tablespace.
3.
Allocate from the database default shared temporary tablespace.
4.
Allocate from the database default local temporary tablespace.
Note: For read-write instances to use a local temporary tablespace, that
temporary tablespace must be created with the LOCAL...FOR ALL option.
Local Temporary Tablespace Features
Instances cannot share local temporary tablespace, hence one instance cannot take
local temporary tablespace from another. If an instance runs out of temporary
tablespace during spilling, then the statement resutls in an error.
•
Local temporary tablespace support only one BIGFILE per tablespace.
•
To address contention issues arising from having only one BIGFILE-based local
temporary tablespace, multiple local temporary tablespaces can be assigned to
different users, as default.
•
A database administrator can specify the default temporary tablespace for a user
using ALTER USER syntax. For example:
ALTER USER MAYNARD LOCAL TEMPORARY TABLESPACE temp_ts_for_rim;
•
A user can be configured with two default temporary tablespaces:
–
One local temporary (created with the FOR RIM option) when the user is
connected to the read-only instance running on reader nodes.
–
One shared temporary tablespace to be used when the same user is connected
on the read-write instances running on a Hub Node.
Metadata Management of Local Temporary Files
Currently, temporary file information (such as file name, creation size, creation SCN,
temporary block size, and file status) is stored in the control file along with the initial
Introduction to Oracle RAC 1-13
Overview of Oracle Clusterware for Oracle RAC
and max files, as well as auto extent attributes. However, the information about local
temporary files in the control file is common to all applicable instances (read write and
read only for LOCAL...FOR ALL, and read only for LOCAL...FOR RIM).
Instance-specific information, such as bitmap for allocation, current size for a
temporary file, and the file status, is stored in the SGA on instances and not in the
control file because this information can be different for different instances. When an
instance starts up, it reads the information in the control file and creates the temporary
files that constitute the local temporary tablespace for that instance. If there are two or
more instances running on a node, then each instance will have its own local
temporary files.
For local temporary tablespaces, there is a separate file for each involved instance. If
you create the local temporary tablespace using the LOCAL...FOR RIM option, then
Oracle creates files only on read-only instances. If you create the local temporary
tablespace using the LOCAL...FOR ALL option, then Oracle creates files on all
instances. The local temporary file names follow a naming convention such that the
instance numbers are appended to the temporary file names specified while creating
the local temporary tablespace.
For example, assume that a read-only node, N1, runs two Oracle read-only database
instances with numbers 3 and 4. The following DDL command creates two files on
node N1—/temp/temp_file_rim_3 and /temp/temp_file_rim_4, for instance
3 and 4 respectively:
CREATE LOCAL TEMPORARY TABLESPACE FOR RIM temp_ts_for_rim TEMPFILE '/temp/
temp_file_rim'\
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M AUTOEXTEND ON;
Assuming that there are two read-write instances (instance numbers 1 and 2) and two
read-only instances (instance numbers 3 and 4), the following DDL command creates
four files—/temp/temp_file_all_1 and /temp/temp_file_all_2 for instances
1 and 2, respectively, and /temp/temp_file_all_3 and /temp/
temp_file_all_4 for instances 3 and 4, respectively:
CREATE LOCAL TEMPORARY TABLESPACE FOR ALL temp_ts_for_all TEMPFILE '/temp/
temp_file_all'\
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M AUTOEXTEND ON;
DDL Support for Local Temporary Tablespaces
You manage local temporary tablespaces and temporary files with either ALTER
TABLESPACE, ALTER DATABASE, or both DDL commands. All DDL commands
related to local temporary tablespace management and creation are run from the readwrite instances. Running all other DDL commands will affect all instances in a
homogeneous manner.
For example, the following command resizes the temporary files on all read-only
instances:
ALTER TABLESPACE temp_ts_for_rim RESIZE 1G;
For local temporary tablespaces, Oracle supports the allocation options and their
restrictions currently active for temporary files.
To run a DDL command on a local temporary tablespace on a read-only instance, only
(in particular, CREATE LOCAL TABLESPACE...FOR RIM or ALTER TABLESPACE
LOCAL TABLESPACE...FOR RIM), there must be at least one read-only instance in
the cluster. This restriction is not applicable when creating or altering local temporary
tablespaces FOR ALL. Users can assign a default local temporary tablespace to the
1-14 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle Clusterware for Oracle RAC
database with a DEFAULT LOCAL TEMPORARY TABLESPACE clause appended to the
ALTER DATABASE command.
Note: The annotation FOR RIM is unnecessary because it is implied by the
name of the table space.
For example:
ALTER DATABASE DEFAULT LOCAL TEMPORARY TABLESPACE temp_ts_for_rim;
A database administrator can specify default temporary tablespace when creating the
database, as follows:
CREATE DATABASE .. DEFAULT TEMPORARY TABLESPACE temp_ts_for_dbtemp_ts_for_rim
TEMPFILE\
'/temp/temp_file_for_dbrim' EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M AUTOEXTEND ON;
It is not possible to specify default local temporary tablespaces using the CREATE
DATABASE command. When you create a database, its default local temporary
tablespace will point to the default shared temporary tablespace. Database
administrators must run the ALTER DATABASE command to assign an existing local
temporary tablespace as the default for the database.
Local Temporary Tablespace for Users
When you create a user without explicitly specifying shared or local temporary
tablespace, the user inherits shared and local temporary tablespace from the
corresponding default database tablespaces. You can specify default local temporary
tablespace for a user, as follows:
CREATE USER new_user IDENTIFIED BY new_user LOCAL TEMPORARY TABLESPACE
temp_ts_for_all;
You can change the local temporary tablespace for a user using the ALTER USER
command, as follows:
ALTER USER maynard LOCAL TEMPORARY TABLESPACE temp_ts_for_rim;
As previously mentioned, default user local temporary tablespace can be shared
temporary space. Consider the following items for the ALTER USER...TEMPORARY
TABLESPACE command:
•
You can change the user default local temporary tablespace to any existing local
temporary tablespace.
•
If you want to set the user default local temporary tablespace to a shared
temporary tablespace, T, then T must be the same as the default shared temporary
tablespace.
•
If a default user local temporary tablespace points to a shared temporary
tablespace, then, when you change the default shared temporary tablespace of the
user, you also change the default local temporary tablespace to that tablespace.
Following are some examples of local temporary space management using the ALTER
command:
•
To take a local temporary tablespace offline:
ALTER DATABASE TEMPFILE ‘/temp/temp_file_rim’ OFFLINE;
Introduction to Oracle RAC 1-15
Overview of Oracle Clusterware for Oracle RAC
•
To decrease the size of a local temporary tablespace:
ALTER TABLESPACE temp_ts_for_rim SHRINK SPACE KEEP 20M
•
To change the auto-extension attributes of a local temporary file:
ALTER TABLESPACE temp_ts_for_rim AUTOEXTEND ON NEXT 20G
•
To resize a local temporary file:
ALTER TABLESPACE temp_ts_for_rim RESIZE 10G
Note: When you resize a local temporary file, it applies to individual files.
Some read-only instances may be down when you run any of the preceding
commands. This does not prevent the commands from succeeding because, when a
read-only instance starts up later, it creates the temporary files based on information
in the control file. Creation is fast because Oracle reformats only the header block of
the temporary file, recording information about the file size, among other things. If
you cannot create any of the temporary files, then the read-only instance stays down.
Commands that were submitted from a read-write instance are replayed, immediately,
on all open read-only instances.
Atomicity Requirement for Commands
All the commands that you run from the read-write instances are performed in an
atomic manner, which means the command succeeds only when it succeeds on all live
instances.
Local Temporary Tablespace and Dictionary Views
Oracle extended dictionary views to display information about local temporary
tablespaces. Oracle made the following changes:
•
All the diagnosibility information related to temporary tablespaces and temporary
files exposed through AWR, SQL monitor, and other utilities, is also available for
local temporary tablespaces and local temporary files. This information is
available with the exisiting dictionary views for temporary tablespaces and
temporary files: DBA_TEMP_FILES, DBA_TEMP_FREE_SPACE.
•
The USER_TABLESPACES and DBA_TABLESPACES dictionary view are extended
by a column, called SHARED, that indicates whether the temporary file is local
(FOR RIM or FOR ALL) or shared.
•
The DBA_TEMP_FILES dictionary view is extended by two columns: SHARED and
INST_ID. The SHARED column indicates whether the temp file is local (FOR RIM
or FOR ALL) or shared. The INST_ID column contains the instance number. For
shared temporary files, there is a single row per file, and the INST_ID is null. For
local temporary files, this column contains information about temporary files per
instance, such as the size of the file in bytes (BYTES column).
Note: LOCAL...FOR RIM shows only read-only instances per file.
•
The DBA_TEMP_FREE_SPACE dictionary view is extended by two columns:
SHARED and INST_ID. The SHARED column indicates whether the temporary file
is local (FOR RIM or FOR ALL) or shared. The INST_ID column contains the
instance number. For shared temporary files, there is a single row per file, and the
INST_ID is null. For local temporary files, this column contains information about
1-16 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle RAC Architecture and Processing
temporary files per instance, such as total free space available (FREE_SPACE
column).
Note: LOCAL...FOR RIM shows only read-only instances per file.
•
In the dictionary views, such as DBA_TABLESPACES, Oracle distinguishes the
type of the tablespace using the SHARED column with the following values:
–
SHARED: for shared temporary tablespace
–
LOCAL_ON_ALL: for local temporary tablespace on all instances
–
LOCAL_ON_RIM: for local temporary tablespace on read-only instances
Note: Currently, spills onto temporary tablespace for queries (such as sort
and hash join spills) are automatically encrypted. This is also true for spills to
local temporary tablespace.
Related Topics:
Oracle Database SQL Language Reference
Overview of Oracle RAC Architecture and Processing
At a minimum, Oracle RAC requires Oracle Clusterware software infrastructure to
provide concurrent access to the same storage and the same set of data files from all
nodes in the cluster, a communications protocol for enabling interprocess
communication (IPC) across the nodes in the cluster, enable multiple database
instances to process data as if the data resided on a logically combined, single cache,
and a mechanism for monitoring and communicating the status of the nodes in the
cluster.
The following sections describe these concepts in more detail:
•
Understanding Cluster-Aware Storage Solutions
•
Oracle RAC and Network Connectivity
•
Overview of Using Dynamic Database Services to Connect to Oracle Databases
•
Restricted Service Registration in Oracle RAC
•
About Oracle RAC Software Components
•
About Oracle RAC Background Processes
Understanding Cluster-Aware Storage Solutions
An Oracle RAC database is a shared everything database. All data files, control files,
SPFILEs, and redo log files in Oracle RAC environments must reside on cluster-aware
shared disks, so that all of the cluster database instances can access these storage
components. Because Oracle RAC databases use a shared everything architecture,
Oracle RAC requires cluster-aware storage for all database files.
In Oracle RAC, the Oracle Database software manages disk access and is certified for
use on a variety of storage architectures. It is your choice how to configure your
Introduction to Oracle RAC 1-17
Overview of Oracle RAC Architecture and Processing
storage, but you must use a supported cluster-aware storage solution. Oracle Database
provides the following storage options for Oracle RAC:
•
Oracle Automatic Storage Management (Oracle ASM)
Oracle recommends this solution to manage your storage.
•
•
A certified cluster file system
–
Oracle recommends Oracle Automatic Storage Management Cluster File
System (Oracle ACFS).
–
A third-party cluster file system on a cluster-aware volume manager that is
certified for Oracle RAC. For example:
*
Oracle OCFS2 (Linux, only)
*
IBM GPFS (IBM AIX, only)
Certified network file system (NFS) solution
Oracle RAC and Network Connectivity
All nodes in an Oracle RAC environment must connect to at least one Local Area
Network (LAN) (commonly referred to as the public network) to enable users and
applications to access the database.
In addition to the public network, Oracle RAC requires private network connectivity
used exclusively for communication between the nodes and database instances
running on those nodes. This network is commonly referred to as the interconnect.
The interconnect network is a private network that connects all of the servers in the
cluster. The interconnect network must use at least one switch and a Gigabit Ethernet
adapter.
Note:
•
Oracle supports interfaces with higher bandwidth but does not support
using crossover cables with the interconnect.
•
Do not use the interconnect (the private network) for user
communication, because Cache Fusion uses the interconnect for
interinstance communication.
You can configure Oracle RAC to use either the User Datagram Protocol (UDP) or
Reliable Data Socket (RDS) protocols for inter-instance communication on the
interconnect. Oracle Clusterware uses the same interconnect using the UDP protocol,
but cannot be configured to use RDS.
An additional network connectivity is required when using Network Attached
Storage (NAS). Network attached storage can be typical NAS devices, such as NFS
filers, or can be storage that is connected using Fibre Channel over IP, for example.
This additional network communication channel should be independent of the other
communication channels used by Oracle RAC (the public and private network
communication). If the storage network communication must be converged with one
of the other network communication channels, then you must ensure that storagerelated communication gets first priority.
1-18 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle RAC Architecture and Processing
Overview of Using Dynamic Database Services to Connect to Oracle Databases
Applications should use the Dynamic Database Services feature to connect to an
Oracle database over the public network.
Dynamic Database Services enable you to define rules and characteristics to control
how users and applications connect to database instances. These characteristics
include a unique name, workload balancing and failover options, and high availability
characteristics.
Users can access an Oracle RAC database using a client/server configuration or
through one or more middle tiers, with or without connection pooling. By default, a
user connection to an Oracle RAC database is established using the TCP/IP protocol
but Oracle supports other protocols. Oracle RAC database instances must be accessed
through the SCAN for the cluster.
Related Topics:
Overview of Automatic Workload Management with Dynamic Database
Services
Services represent groups of applications with common attributes,
service level thresholds, and priorities.
Overview of Virtual IP Addresses
Oracle Clusterware hosts node virtual IP (VIP) addresses on the public network. Node
VIPs are VIP addresses that clients use to connect to an Oracle RAC database. A
typical connect attempt from a database client to an Oracle RAC database instance can
be summarized, as follows:
1.
The database client connects to SCAN (which includes a SCAN VIP on a public
network), providing the SCAN listener with a valid service name.
2.
The SCAN listener then determines which database instance hosts this service and
routes the client to the local or node listener on the respective node.
3.
The node listener, listening on a node VIP and a given port, retrieves the
connection request and connects the client to the an instance on the local node.
If multiple public networks are used on the cluster to support client connectivity
through multiple subnets, then the preceding operation is performed within a given
subnet.
If a node fails, then the VIP address fails over to another node on which the VIP
address can accept TCP connections, but it does not accept connections to the Oracle
database. Clients that attempt to connect to a VIP address not residing on its home
node receive a rapid connection refused error instead of waiting for TCP connect timeout
messages. When the network on which the VIP is configured comes back online,
Oracle Clusterware fails back the VIP to its home node, where connections are
accepted. Generally, VIP addresses fail over when:
•
The node on which a VIP address runs fails
•
All interfaces for the VIP address fail
•
All interfaces for the VIP address are disconnected from the network
Oracle RAC 12c supports multiple public networks to enable access to the cluster
through different subnets. Each network resource represents its own subnet and each
Introduction to Oracle RAC 1-19
Overview of Oracle RAC Architecture and Processing
database service uses a particular network to access the Oracle RAC database. Each
network resource is a resource managed by Oracle Clusterware, which enables the VIP
behavior previously described.
SCAN is a single network name defined either in your organization's Domain Name
Server (DNS) or in the Grid Naming Service (GNS) that round robins to three IP
addresses. Oracle recommends that all connections to the Oracle RAC database use the
SCAN in their client connection string. Incoming connections are load balanced across
the active instances providing the requested service through the three SCAN listeners.
With SCAN, you do not have to change the client connection even if the configuration
of the cluster changes (nodes added or removed). Unlike in previous releases, SCAN
in Oracle RAC 12c fully supports multiple subnets, which means you can create one
SCAN for each subnet in which you want the cluster to operate.
Restricted Service Registration in Oracle RAC
The valid node checking feature provides the ability to configure and dynamically
update a set of IP addresses or subnets from which registration requests are allowed
by the listener.
Database instance registration with a listener succeeds only when the request
originates from a valid node. The network administrator can specify a list of valid
nodes, excluded nodes, or disable valid node checking. The list of valid nodes
explicitly lists the nodes and subnets that can register with the database. The list of
excluded nodes explicitly lists the nodes that cannot register with the database. The
control of dynamic registration results in increased manageability and security of
Oracle RAC deployments.
By default, valid node checking for registration (VNCR) is enabled. In the default
configuration, registration requests from all nodes within the subnet of the SCAN
listener can register with the listener. Non-SCAN listeners only accept registration
from instances on the local node. Remote nodes or nodes outside the subnet of the
SCAN listener must be included on the list of valid nodes by using the
registration_invited_nodes_alias parameter in the listener.ora file or
by modifying the SCAN listener using SRVCTL.
About Oracle RAC Software Components
Oracle RAC databases generally have two or more database instances that each
contain memory structures and background processes. An Oracle RAC database has
the same processes and memory structures as a noncluster Oracle database and
additional processes and memory structures that are specific to Oracle RAC. Any one
instance's database view is nearly identical to any other instance's view in the same
Oracle RAC database; the view is a single system image of the environment.
Each instance has a buffer cache in its System Global Area (SGA). Using Cache Fusion,
Oracle RAC environments logically combine each instance's buffer cache to enable the
instances to process data as if the data resided on a logically combined, single cache.
Note:
•
The In-Memory Transaction Manager integrates with the Cache Fusion
protocol.
•
The SGA size requirements for Oracle RAC are greater than the SGA
requirements for noncluster Oracle databases due to Cache Fusion.
1-20 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle RAC Architecture and Processing
To ensure that each Oracle RAC database instance obtains the block that it requires to
satisfy a query or transaction, Oracle RAC instances use two processes, the Global
Cache Service (GCS) and the Global Enqueue Service (GES). The GCS and GES
maintain records of the statuses of each data file and each cached block using a Global
Resource Directory (GRD). The GRD contents are distributed across all of the active
instances, which effectively increases the size of the SGA for an Oracle RAC instance.
After one instance caches data, any other instance within the same cluster database
can acquire a block image from another instance in the same database faster than by
reading the block from disk. Therefore, Cache Fusion moves current blocks between
instances rather than re-reading the blocks from disk. When a consistent block is
needed or a changed block is required on another instance, Cache Fusion transfers the
block image directly between the affected instances. Oracle RAC uses the private
interconnect for interinstance communication and block transfers. The GES Monitor
and the Instance Enqueue Process manage access to Cache Fusion resources and
enqueue recovery processing.
Related Topics:
Oracle Database In-Memory Guide
About Oracle RAC Background Processes
The GCS and GES processes, and the GRD collaborate to enable Cache Fusion. The
Oracle RAC processes and their identifiers are as follows:
•
ACMS: Atomic Controlfile to Memory Service (ACMS)
In an Oracle RAC environment, the ACMS per-instance process is an agent that
contributes to ensuring a distributed SGA memory update is either globally
committed on success or globally aborted if a failure occurs.
•
GTX0-j: Global Transaction Process
The GTX0-j process provides transparent support for XA global transactions in
an Oracle RAC environment. The database autotunes the number of these
processes based on the workload of XA global transactions.
•
LMON: Global Enqueue Service Monitor
The LMON process monitors global enqueues and resources across the cluster and
performs global enqueue recovery operations.
•
LMD: Global Enqueue Service Daemon
The LMD process manages incoming remote resource requests within each
instance.
•
LMS: Global Cache Service Process
The LMS process maintains records of the data file statuses and each cached block
by recording information in a Global Resource Directory (GRD). The LMS process
also controls the flow of messages to remote instances and manages global data
block access and transmits block images between the buffer caches of different
instances. This processing is part of the Cache Fusion feature.
•
LCK0: Instance Enqueue Process
The LCK0 process manages non-Cache Fusion resource requests such as library
and row cache requests.
Introduction to Oracle RAC 1-21
Overview of Automatic Workload Management with Dynamic Database Services
•
RMSn: Oracle RAC Management Processes (RMSn)
The RMSn processes perform manageability tasks for Oracle RAC. Tasks
accomplished by an RMSn process include creation of resources related to Oracle
RAC when new instances are added to the clusters.
•
RSMN: Remote Slave Monitor manages background slave process creation and
communication on remote instances. These background slave processes perform
tasks on behalf of a coordinating process running in another instance.
Note:
Many of the Oracle Database components that this section describes are in
addition to the components that are described for noncluster Oracle databases
in Oracle Database Concepts.
Related Topics:
Oracle Database Concepts
Overview of Automatic Workload Management with Dynamic Database
Services
Services represent groups of applications with common attributes, service level
thresholds, and priorities.
Application functions can be divided into workloads identified by services. For
example, Oracle E-Business Suite can define a service for each responsibility, such as
general ledger, accounts receivable, order entry, and so on. A service can span one or
more instances of an Oracle database, multiple databases in a global cluster, and a
single instance can support multiple services. The number of instances that are serving
the service is transparent to the application. Services provide a single system image to
manage competing applications, and allow each workload to be managed as a unit.
Middle tier applications and clients select a service by specifying the service name as
part of the connection in the TNS connect string. For example, data sources for Oracle
WebLogic Server are set to route to a service. Using Net Easy*Connection, this
connection comprises simply the service name and network address, as follows:
user_name/[email protected]/service_name. Server-side work such as Oracle
Scheduler, Parallel Query, and Oracle Streams queues set the service name as part of
the workload definition. For Oracle Scheduler, jobs are assigned to job classes and job
classes execute within services. For Parallel Query and Parallel DML, the query
coordinator connects to a service and the parallel query slaves inherit the service for
the duration of the parallel execution. For Oracle Streams, streams queues are accessed
using services. Work executing under a service inherits the thresholds and attributes
for the service and is measured as part of the service.
Oracle Database Resource Manager binds services to consumer groups and priorities.
This allows the database to manage the services in the order of their importance. For
example, the DBA can define separate services for high priority online users and lower
priority internal reporting applications. Likewise, the DBA can define Gold, Silver and
Bronze services to prioritize the order in which requests are serviced for the same
application. When planning the services for a system, the plan should include the
priority of each service relative to the other services. In this way, Oracle Database
Resource Manager can satisfy the priority-one services first, followed by the prioritytwo services, and so on.
1-22 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Automatic Workload Management with Dynamic Database Services
When users or applications connect to a database, Oracle recommends that you use a
service specified in the CONNECT_DATA portion of the connect string. Oracle Database
automatically creates one database service when the database is created but the
behavior of this service is different from that of database services that you
subsequently create. To enable more flexibility in the management of a workload
using the database, Oracle Database enables you to create multiple services and
specify on which instances (or in which server pools) the services start. If you are
interested in greater workload management flexibility, then continue reading this
chapter to understand the added features that you can use with services.
Note:
The features discussed in this chapter do not work with the following default
database services: DB_NAME, DB_UNIQUE_NAME, PDB_NAME, SYS
$BACKGROUND, and SYS$USERS. Oracle strongly recommends that you do not
use these services for applications to connect to the database. You must create
cluster managed services to take advantage of these features. You can only
manage the services that you create. Any service that the database create
automatically is managed by the database server.
Dynamic Database Services
Dynamic database services enable you to manage workload distributions to provide
optimal performance for users and applications. Dynamic database services offer the
following features:
•
Services: Oracle Database provides a powerful automatic workload management
facility, called services, to enable the enterprise grid vision. Services are entities
that you can define in Oracle RAC databases that enable you to group database
workloads, route work to the optimal instances that are assigned to offer the
service, and achieve high availability for planned and unplanned actions.
•
High Availability Framework: An Oracle RAC component that enables Oracle
Database to always maintain components in a running state.
•
Fast Application Notification (FAN): Provides information to Oracle RAC
applications and clients about cluster state changes and Load Balancing Advisory
events, such as UP and DOWN events for instances, services, or nodes. FAN has two
methods for publishing events to clients, the Oracle Notification Service daemon,
which is used by Java Database Connectivity (JDBC) clients including the Oracle
Application Server, and Oracle Streams Advanced Queueing, which is only used
by previous releases of Oracle Call Interface (OCI) and Oracle Data Provider
for .NET (ODP.NET) clients.
Note:
All clients beginning with Oracle Database 12c release 2 (12.2) use Oracle
Notification Service.
•
Transaction Guard: A tool that provides a protocol and an API for at-most-once
execution of transactions in case of unplanned outages and duplicate submissions.
•
Application Continuity: Provides a general purpose infrastructure that replays
the in-flight request when a recoverable error is received, masking many system,
Introduction to Oracle RAC 1-23
Overview of Server Pools and Policy-Managed Databases
communication, and storage outages, and hardware failures. Unlike existing
recovery technologies, this feature attempts to recover the transactional and nontransactional session states beneath the application, so that the outage appears to
the application as a delayed execution.
•
Connection Load Balancing: A feature of Oracle Net Services that balances
incoming connections across all of the instances that provide the requested
database service.
•
Load Balancing Advisory: Provides information to applications about the current
service levels that the database and its instances are providing. The load balancing
advisory makes recommendations to applications about where to direct
application requests to obtain the best service based on the management policy
that you have defined for that service. Load balancing advisory events are
published through Oracle Notification Service.
•
Automatic Workload Repository (AWR): Tracks service-level statistics as metrics.
Server generated alerts can be created for these metrics when they exceed or fail to
meet certain thresholds.
•
Fast Connection Failover (FCF): This is the ability of Oracle Clients to provide
rapid failover of connections by subscribing to FAN events.
•
Runtime Connection Load Balancing: This is the ability of Oracle Clients to
provide intelligent allocations of connections in the connection pool based on the
current service level provided by the database instances when applications
request a connection to complete some work.
•
Single Client Access Name (SCAN): Provides a single name to the clients
connecting to Oracle RAC that does not change throughout the life of the cluster,
even if you add or remove nodes from the cluster. Clients connecting with SCAN
can use a simple connection string, such as a thin JDBC URL or EZConnect, and
still achieve the load balancing and client connection failover.
You can deploy Oracle RAC and noncluster Oracle database environments to use
dynamic database service features in many different ways. Depending on the number
of nodes and your environment's complexity and objectives, your choices for optimal
automatic workload management and high-availability configuration depend on
several considerations that are described in this chapter.
Related Topics:
Oracle Database Administrator’s Guide
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Overview of Server Pools and Policy-Managed Databases
Server pools are the basis for policy-managed databases.
You can create Oracle RAC databases, whether multinode or Oracle Real Application
Clusters One Node (Oracle RAC One Node), using the following deployment models:
•
Administrator-managed deployment is based on the Oracle RAC deployment
types that existed before Oracle Database 11g release 2 (11.2) and requires that you
statically configure each database instance to run on a specific node in the cluster,
1-24 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Server Pools and Policy-Managed Databases
and that you configure database services to run on specific instances belonging to
a certain database using the preferred and available designation.
•
Policy-managed deployment is based on server pools, where database services run
within a server pool as singleton or uniform across all of the servers in the server
pool. Databases are deployed in one or more server pools and the size of the
server pools determine the number of database instances in the deployment.
Related Topics:
Oracle Database Quality of Service Management User's Guide
Introduction to Server Pools
Server pools logically apportion a cluster into groups of servers offering database or
application services.
Server pool properties control the scalability and availability of those databases and
applications. You can configure each server pool with a minimum and maximum size,
which determines scalability. Oracle Clusterware manages availability between server
pools, and you can further regulate availability by configuring the importance value of
individual server pools.
Servers are not assigned to server pools by name but by number. Therefore, you must
configure any server to run any database. If you cannot configure servers due to, for
example, heterogeneous servers or storage connectivity, then you can restrict servers
by using server category definitions to determine server pool membership eligibility.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Examples of Using Server Pools
This section includes the following examples of using server pools:
•
Minimum and Maximum Number of Servers
•
IMPORTANCE Attribute of Server Pools
•
Consolidation of Databases
Minimum and Maximum Number of Servers
Consider a four-node cluster configured into two server pools named online and
backoffice. A database named dbsales runs in the online server pool offering
the browse, search, and salescart services. A database named dberp runs in the
backoffice server pool and offers the inventory and shipping services, as
shown in Figure 1-2. During normal business hours the enterprise requires a
minimum of two instances of the dbsales database and one instance of the dberp
database to meet normal demand.
Introduction to Oracle RAC 1-25
Overview of Server Pools and Policy-Managed Databases
Figure 1-2
Server Placement by Minimum and Maximum Limits
Online Server Pool
Backoffice Server Pool
Free Server Pool
Min = 2, Max = 3, Imp = 5
Min = 1, Max = 2, Imp = 10
Min = 0, Max = 1, Imp = 0
dbsales
browse
search
ASM Disk
Groups
dberp
rp
salescart
ASM Disk
Groups
inventory
ASM Disk
Groups
shipping
ASM Disk
Groups
In this policy-managed deployment, the value of the MIN_SIZE server pool attribute
for the online server pool is 2, while the value of the MIN_SIZE server pool attribute
for the backoffice server pool is 1. Configured this way, Oracle Clusterware
ensures that there are always two servers in the online server pool and one server in
the backoffice server pool. Because this is a four-node cluster, there is one server
left not assigned to either server pool. Where that last server gets deployed is
determined by the MAX_SIZE server pool parameter of each server pool. If the sum of
the values of the MAX_SIZE server pool attribute for each server pool is less than the
total number of servers in the cluster, then the remaining servers stay in the Free
server pool awaiting a failure of a deployed node.
If the value of MAX_SIZE is greater than that of MIN_SIZE, then the remaining server
will be deployed into the server pool whose importance value is greatest, as shown in
Figure 1-2, and fully discussed in the next section. In this case, the server is a shareable
resource that can be relocated online to join the server pool where it is required. For
example, during business hours the server could be given to the online server pool
to add an instance of the dbsales database but after hours could be relocated to the
backoffice server pool, adding a dberp database instance. All such movements are
online and instances are shut down, transactionally.
These two policy-managed databases are running only the instances that are required
and they can be dynamically increased or decreased to meet demand or business
requirements.
IMPORTANCE Attribute of Server Pools
The IMPORTANCE server pool attribute is used at cluster startup and in response to a
node failure or eviction. In contrast to administrator-managed databases, you can
configure server pools with different importance levels to determine which databases
are started first and which databases remain online in case there is a multinode
outage.
1-26 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Server Pools and Policy-Managed Databases
Consider a four-node cluster that hosts a database named dbapps in two server pools,
sales and backoffice. Two services, orderentry and billing, run in the
sales server pool, while two other services, erp and reports, run in the
backoffice server pool, as shown in Figure 1-3. By configuring the value of the
IMPORTANCE server pool attribute of the sales server pool higher than that of the
backoffice server pool, the services in sales start first when the cluster starts and
are always available, even if there is only one server left running after a multinode
failure. The IMPORTANCE server pool attribute enables you to rank services and also
eliminates the requirement to run a service on all nodes in a cluster to ensure that it is
always available.
Figure 1-3
Server Pool Importance
Sales Server Pool
Backoffice Server Pool
Free Server Pool
Min = 2, Max = 3, Imp = 5
Min = 2, Max = 2, Imp = 10
Min = 0, Max = -1, Imp = 0
dbapps
pps
orderentry
ASM Disk
Groups
dbapps
pps
billing
erp
ASM Disk
Groups
ASM Disk
Groups
reports
ASM Disk
Groups
Consolidation of Databases
You can use several different approaches, either discretely or combined, to consolidate
Oracle databases. Policy-managed deployments facilitate consolidation. In the case of
schema consolidation, where multiple applications are being hosted in a single
database separated into discrete schemas or pluggable databases (PDBs), you can use
server pools to meet required capacity. Because of the dynamic scaling property of
server pools, you can increase or decrease the number of database instances to meet
current demand or business requirements. Since server pools also determine which
services run together or separately, you can configure and maintain required affinity
or isolation.
When it is not possible to use schema consolidation because of, for example, version
requirements, you can host multiple databases on a single set of servers. Using policymanaged databases facilitates this database consolidation because they can share the
same server pool by making use of instance caging, which enables you to dynamically
increase or decrease databases, both horizontally (using server pool size) and
vertically (using the CPU_COUNT server configuration attribute) to meet demand or
business policies and schedules.
Introduction to Oracle RAC 1-27
Overview of Server Pools and Policy-Managed Databases
By contrast, with administrator-managed databases, you are required to reserve
capacity on each server to absorb workload failing over should a database instance or
server fail. With policy-managed databases, however, you can effectively rank server
pools by the business necessity of the workloads that they are running using the
MIN_SIZE, MAX_SIZE, and IMPORTANCE server pool attributes.
When the failure of a server brings a server pool to below its configured minimum
number of servers, another server will move from a less important server pool to take
its place and bring the number of servers back up to the configured minimum. This
eliminates the risk of cascade failures due to overloading the remaining servers and
enables you to significantly reduce or even eliminate the need to reserve capacity for
handling failures.
Migrating or converting to policy-managed databases also enables cluster
consolidation and creates larger clusters that have greater availability and scalability
because of the increased number of servers available to host and scale databases.
Because policy-managed databases do not require binding their instance names to a
particular server and binding services to particular instances, the complexity of
configuring and managing large clusters is greatly reduced.
An example deployment is shown in Figure 1-4 where the previous two cluster
examples (shown in Figure 1-2 and Figure 1-3) are consolidated into a single cluster,
making use of both database consolidation (using instance caging) and cluster
consolidation (using server pools) configured so that workloads are properly sized
and prioritized.
Figure 1-4
Consolidating Databases
Online Server Pool
Backoffice Server Pool
Free Server Pool
Min = 2, Max = 3, Imp = 5
Min = 2, Max = 2, Imp = 10
Min = 0, Max = -1, Imp = 0
dbsales CPU=6
browse
search
dberp
rp CPU=4
salescart
inventory
dbapps
pps CPU=6
orderentry
ASM Disk
Groups
shipping
dbapps
pps CPU=8
billing
erp
ASM Disk
Groups
ASM Disk
Groups
reports
ASM Disk
Groups
Related Topics:
Oracle Clusterware Administration and Deployment Guide
1-28 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Server Pools and Policy-Managed Databases
Deploying Policy-Managed Databases
When you deploy a policy-managed database you must first determine the services
and their required sizing, taking into account that services cannot span server pools.
If you are going to collocate this database with other databases, then you should factor
in its CPU requirements relative to the other hosted databases, and also factor in the
value of its CPU_COUNT attribute for instance caging, so that you can size the database
both vertically and horizontally in one or more server pools.
If you are going to collocate the server pools for this database with other server pools,
then consider configuring the server pools to adjust the server pool sizes on a calendar
or event basis to optimize meeting demand and business requirements. Once you have
determined the sizes of the server pools, and configured the appropriate values for the
MIN_SIZE and MAX_SIZE server pool attributes, you can then determine the relative
importance of each server pool.
You, as the cluster administrator, create policy-managed database server pools using
the srvctl add serverpool command. You can modify the properties of the
server pool using the srvctl modify serverpool command in the Oracle Grid
Infrastructure home.
While it is possible to create a server pool using DBCA, Oracle recommends this only
for small, single server pool deployments, because DBCA will fail if servers are
already allocated to other server pools. Additionally, if the cluster is made up of
servers with different capacities, such as old and new servers, Oracle recommends that
you set up server category definitions defining the minimum server requirements for a
server to join each server pool.
After you create the server pools, you can run DBCA from the appropriate database
home. Depending on the database type and task, you will be presented with different
default options. For all new Oracle RAC and Oracle RAC One Node databases,
including container databases (CDBs), the Policy-Managed option is the default and
the option that Oracle recommends.
If you are upgrading your database from an administrator-managed database or a
database earlier than Oracle Database 11g release 2 (11.2), then you will not have the
option to directly upgrade to a policy-managed database. After you upgrade,
however, you can convert the database to policy managed using the srvctl modify
database command.
When you convert from an administrator-managed database to a policy-managed
database, the instance names are automatically updated to include the underscore (for
example: orcl1 becomes orcl_1). The underscore is required so that the database
can automatically create instances when a server pool grows in size.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Database Quality of Service Management User's Guide
Oracle Clusterware Administration and Deployment Guide
Converting an Administrator-Managed Database to a Policy-Managed Database
You can convert an administrator-managed database to a policymanaged database.
Introduction to Oracle RAC 1-29
Overview of Server Pools and Policy-Managed Databases
Managing Policy-Managed Databases
Managing a policy-managed database requires less configuration and reconfiguration
steps than an administrator-managed one with respect to creation, sizing, patching,
and load balancing.
Also, because any server in the server pools within the cluster can run any of the
databases, you do not have to create and maintain database instance-to-node-name
mappings. If, however, you want a database to use a specific instance name whenever
it runs on a particular node, then you can create instance-to-node-name mappings
using the srvctl modify instance -db db_unique_name -instance
inst_name -node node_name command. This can be useful when scripts on a
particular node connect to the database using a fixed ORACLE_SID value.
You can perform maintenance tasks such as patching by relocating servers into the
Free pool or by adjusting the server pool minimum and maximum sizes, thereby
retaining required availability.
Policy-managed databases also facilitate the management of services, because they are
assigned to a single server pool and run as singletons or uniform across all servers in
the pool. You no longer have to create or maintain explicit preferred and available
database instance lists for each service. If a server moves into a server pool because of
manual relocation or a high availability event, all uniform services and their
dependent database instances are automatically started. If a server hosting one or
more singleton services goes down, those services will automatically be started on one
or more of the remaining servers in the server pool. In the case of Oracle RAC One
Node, the corresponding database instance will also be started automatically.
Managing services relative to each other is improved by making use of the importance
attribute of each server pool. Each service running in a server pool inherits the server
pool's importance relative to the other server pool-hosted services in the cluster. If the
minimum size of the most important server pool is greater than zero, then the services
and associated database instances in that server pool are started first on cluster startup
and will be the last services and database instances running, as long as there is one
server running in the cluster. You can offer services not critical to the business in the
least important server pool, ensuring that, should sufficient resources not be available
due to demand or failures, those services will eventually be shut down and the more
business-critical services remain available.
Because many management tasks may involve making changes that can affect
multiple databases, services, or server pools in a consolidated environment, you can
use the evaluate mode for certain SRVCTL commands to get a report of the resource
impact of a command.
Consider the following example, that evaluates the effect on the system of modifying a
server pool:
$ srvctl modify srvpool -l 3 -g online -eval
Service erp1 will be stopped on node test3
Service reports will be stopped on node test3
Service inventory will be stopped on node test3
Service shipping will be stopped on node test3
Database dbsales will be started on node test3
Service orderentry will be started on node test3
Service billing will be started on node test3
Service browse will be started on node test3
Service search will be started on node test3
1-30 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Server Pools and Policy-Managed Databases
Service salescart will be started on node test3
Server test3 will be moved from pool backoffice to pool online
As shown in the preceding example, modifying a server pool can result in many
resource state changes. You can use a policy set through either Oracle Clusterware or
Oracle Database Quality of Service Management.
Related Topics:
srvctl modify srvpool
srvctl relocate server
SRVCTL Usage Information
SRVCTL is installed on each node in a cluster by default. To use
SRVCTL, log in to the operating system of a node and enter the SRVCTL
command and its parameters in case-sensitive syntax.
Oracle Clusterware Administration and Deployment Guide
Oracle Database Quality of Service Management User's Guide
Policy-Based Cluster Management
Oracle Clusterware supports the management of a cluster configuration policy set as a
native Oracle Clusterware feature.
A cluster configuration policy contains one definition for each server pool that is
defined in the system. A cluster configuration policy also specifies resource placement
and cluster node availability. A cluster configuration policy set defines the names of
all of the server pools that are configured in a cluster, and contains one or more
configuration policies.
There is always only one configuration policy in effect at any one time. However,
administrators typically create several configuration policies to reflect the different
business needs and demands based on calendar dates or time of day parameters. For
instance, morning hours during business days are typically when most users log in
and download their email; email-related workloads are usually light at nighttime and
on weekends. In such cases, you can use cluster configuration policies to define the
server allocation based on the expected demand. More specifically for this example, a
configuration policy that allocates more servers to OLTP workloads is in effect during
workday mornings, and another configuration policy allocates more servers to batch
workloads on weekends and workday evenings.
Using cluster configuration policies can also help manage clusters that comprise
servers of different capabilities, such as different computer and memory sizes
(heterogeneous). To create management and availability policies for clusters
comprised of heterogeneous server types, the cluster administrator can create server
categories based on server attributes. These attributes can restrict which servers can be
assigned to which server pools. For example, if you have some servers in a cluster that
run older hardware, then you can use an attribute to specify that these servers should
only be allocated to the server pools that support batch jobs and testing, instead of
allocating them to the server pools that are used for online sales or other businesscritical applications.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Introduction to Oracle RAC 1-31
Overview of Oracle Database Quality of Service Management
Overview of Oracle Database Quality of Service Management
Oracle Database Quality of Service Management (Oracle Database QoS Management)
is an automated, policy-based product that monitors the workload requests for an
entire system.
Oracle Database QoS Management manages the resources that are shared across
applications, and adjusts the system configuration to keep the applications running at
the performance levels needed by your business. Oracle Database QoS Management
responds gracefully to changes in system configuration and demand, thus avoiding
additional oscillations in the performance levels of your applications.
Oracle Database QoS Management monitors and manages Oracle RAC database
workload performance objectives by identifying bottlenecked resources impacting
these objectives, and both recommending and taking actions to restore performance.
Administrator-managed deployments bind database instances to nodes but policymanaged deployments do not, so the Oracle Database QoS Management server pool
size resource control is only available for the latter. All other resource management
controls are available for both deployments.
Oracle Database QoS Management supports administrator-managed Oracle RAC and
Oracle RAC One Node databases with its Measure-Only, Monitor, and Management
modes. This enables schema consolidation support within an administrator-managed
Oracle RAC database by adjusting the CPU shares of performance classes running in
the database. Additionally, database consolidation is supported by adjusting CPU
counts for databases hosted on the same physical servers.
Because administrator-managed databases do not run in server pools, the ability to
expand or shrink the number of instances by changing the server pool size that is
supported in policy-managed database deployments is not available for administratormanaged databases. This new deployment support is integrated into the Oracle QoS
Management pages in Oracle Enterprise Manager Cloud Control.
Related Topics:
Oracle Database Quality of Service Management User's Guide
Overview of Hang Manager
Hang Manager is an Oracle Database feature that automatically detects and resolves
system hangs.
Hang Manager was first available in Oracle Database 11g release 1 (11.1) and, initially,
identified system hangs and then dumped the relevant information about the hang
into a trace file. In Oracle Database 12c release 2 (12.2), Hang Manager can take action
on and attempt to resolve the system hang. Hang Manager also runs in both singleinstance and Oracle RAC database instances.
Note: Hang manager does not resolve dead locks, although dead lock
detection has been available in Oracle Database for several of the past releases.
Hang Manager functions, as follows:
•
First detects a system hang and then analyzes the hang and verifies the cause of
the hang. It then applies heuristics to decide on a course of action to resolve the
hang.
1-32 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle Multitenant with Oracle RAC
•
Automates the tasks that used to require manual steps by a DBA to provide the
trace files to My Oracle Support so that someone there could identify the source of
the hang, minimizing or eliminating database and application downtime.
•
Periodically scans all processes and analyzes a smaller subset of processes that are
holding resources in successive scans. Hang manager ignores processes if there is
nothing waiting on the resource.
•
Considers cross-instance hangs, which are hangs where the holder is a database
process waiting on a response from an Oracle ASM instance.
•
Is aware of processes running in reader nodes instances, and checks whether any
of these processes are blocking progress on Hub Nodes and takes action, if
possible.
•
Considers the Oracle Database Quality of Service Management settings of the
holder.
•
Terminates the holder process so the next process waiting on that resource can
move on and prevent a hang.
•
Notifies a DBA with an ORA-32701 error message in the alert log.
See Also: Oracle Autonomous Health Framework User's Guide
Overview of Oracle Multitenant with Oracle RAC
Oracle Multitenant is an option with Oracle Database 12c that simplifies consolidation,
provisioning, upgrades, and more.
It is based on an architecture that allows a multitenant container database (CDB) to
hold several pluggable databases (PDBs). You can adopt an existing database as a PDB
without having to change the application tier. In this architecture, Oracle RAC
provides the local high availability that is required when consolidating various
business-critical applications on one system.
When using PDBs with Oracle RAC, the multitenant CDB is based on Oracle RAC.
You can make each PDB available on either every instance of the Oracle RAC CDB or a
subset of instances. In either case, access to and management of the PDBs are
regulated using dynamic database services, which will also be used by applications to
connect to the respective PDB, as they would in a single instance Oracle database
using Oracle Net Services for connectivity.
You can isolate PDBs to prevent certain operations from being performed on or within
a particular PDB that may interfere with other PDBs sharing the same Oracle RAC
database or database instance. PDB isolation allows for a higher degree of
consolidation using Oracle Multitenant.
If you create an Oracle RAC database as a CDB and plug one or more PDBs into the
CDB, then, by default, a PDB is not started automatically on any instance of the Oracle
RAC CDB. With the first dynamic database service assigned to the PDB (other than the
default database service which has the same name as the database name), the PDB is
made available on those instances on which the service runs.
Whether a PDB is available on more than one instance of an Oracle RAC CDB, the
CDB is typically managed by the services running on the PDB. You can manually
enable PDB access on each instance of an Oracle RAC CDB by starting the PDB
manually on that instance.
Introduction to Oracle RAC 1-33
Overview of Database In-Memory and Oracle RAC
Overview of Database In-Memory and Oracle RAC
Each node in an Oracle RAC environment has its own In-Memory (IM) column store.
By default, populated objects are distributed across all IM column stores in the cluster.
Each node in an Oracle RAC environment has its own In-Memory (IM) column store.
Oracle recommends that you equally size the IM column stores on each Oracle RAC
node. For any Oracle RAC node that does not require an IM column store, set the
INMEMORY_SIZE parameter to 0.
It is possible to have completely different objects populated on every node, or to have
larger objects distributed across all of the IM column stores in the cluster. It is also
possible to have the same objects appear in the IM column store on every node (on
engineered systems, only). The distribution of objects across the IM column stores in a
cluster is controlled by two additional sub-clauses to the INMEMORY attribute;
DISTRIBUTE and DUPLICATE.
In an Oracle RAC environment, an object that only has the INMEMORY attribute
specified on it is automatically distributed across the IM column stores in the cluster.
The DISTRIBUTE clause can be used to specify how an object is distributed across the
cluster. By default, the type of partitioning used (if any) determines how the object is
distributed. If the object is not partitioned it is distributed by rowid range.
Alternatively, you can specify the DISTRIBUTE clause to over-ride the default
behavior.
On an Engineered System, it is possible to duplicate or mirror objects populated in
memory across the IM column store in the cluster. This provides the highest level of
redundancy. The DUPLICATE clause is used to control how an object should be
duplicated across the IM column stores in the cluster. If you specify just DUPLICATE,
then one mirrored copy of the data is distributed across the IM column stores in the
cluster. If you want to duplicate the entire object in each IM column store in the
cluster, then specify DUPLICATE ALL.
Note:
When you deploy Oracle RAC on a non-Engineered System, the DUPLICATE
clause is treated as NO DUPLICATE.
Related Topics:
Oracle Database In-Memory Guide
Overview of Managing Oracle RAC Environments
This section describes the following Oracle RAC environment management topics:
•
About Designing and Deploying Oracle RAC Environments
•
About Administrative Tools for Oracle RAC Environments
•
About Monitoring Oracle RAC Environments
•
About Evaluating Performance in Oracle RAC Environments
1-34 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Managing Oracle RAC Environments
About Designing and Deploying Oracle RAC Environments
Any enterprise that is designing and implementing a high availability strategy with
Oracle RAC must begin by performing a thorough analysis of the business drivers that
require high availability.
An analysis of business requirements for high availability combined with an
understanding of the level of investment required to implement different high
availability solutions enables the development of a high availability architecture that
achieves both business and technical objectives.
Related Topics:
Design and Deployment Techniques
Oracle Database High Availability Overview
See Also:
For help choosing and implementing the architecture that best fits your
availability requirements:
•
"Design and Deployment Techniques" provides a high-level overview you
can use to evaluate the high availability requirements of your business.
•
Oracle Database High Availability Overview describes how to select the most
suitable architecture for your organization, describes several high
availability architectures, and provides guidelines for choosing the one
that best meets your requirements, and also provides information about
the Oracle Maximum Availability Architecture
About Administrative Tools for Oracle RAC Environments
You administer a cluster database as a single-system image using the Server Control
Utility (SRVCTL), Oracle Enterprise Manager, SQL*Plus, and other utilities.
•
Server Control Utility (SRVCTL): SRVCTL is a command-line interface that you
can use to manage an Oracle RAC database from a single point. You can use
SRVCTL to start and stop the database and instances and to delete or move
instances and services. You can also use SRVCTL to manage configuration
information, Oracle Real Application Clusters One Node (Oracle RAC One Node),
Oracle Clusterware, and Oracle ASM.
•
Rapid Home Provisioning: Use Rapid Home Provisioning to patch, upgrade, and
provision Oracle RAC databases.
•
Oracle Enterprise Manager: Oracle Enterprise Manager Cloud Control GUI
interface for managing both noncluster database and Oracle RAC database
environments. Oracle recommends that you use Oracle Enterprise Manager to
perform administrative tasks whenever feasible.
You can use Oracle Enterprise Manager Cloud Control to also manage Oracle
RAC One Node databases.
•
SQL*Plus: SQL*Plus commands operate on the current instance. The current
instance can be either the local default instance on which you initiated your
Introduction to Oracle RAC 1-35
Overview of Managing Oracle RAC Environments
SQL*Plus session, or it can be a remote instance to which you connect with Oracle
Net Services.
•
Cluster Verification Utility (CVU): CVU is a command-line tool that you can use
to verify a range of cluster and Oracle RAC components, such as shared storage
devices, networking configurations, system requirements, and Oracle
Clusterware, in addition to operating system groups and users. You can use CVU
for preinstallation checks and for postinstallation checks of your cluster
environment. CVU is especially useful during preinstallation and during
installation of Oracle Clusterware and Oracle RAC components. Oracle Universal
Installer runs CVU after installing Oracle Clusterware and Oracle Database to
verify your environment.
Install and use CVU before you install Oracle RAC to ensure that your
configuration meets the minimum Oracle RAC installation requirements. Also,
use CVU for verifying the completion of ongoing administrative tasks, such as
node addition and node deletion.
•
DBCA: The recommended utility for creating and initially configuring Oracle
RAC, Oracle RAC One Node, and Oracle noncluster databases.
•
NETCA: Configures the network for your Oracle RAC environment.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Administering Database Instances and Cluster Databases
Monitoring Oracle RAC and Oracle Clusterware
Server Control Utility Reference
Oracle Clusterware Administration and Deployment Guide
Oracle Database Net Services Administrator's Guide
See Also:
•
"Administering Database Instances and Cluster Databases" for an
introduction to Oracle RAC administration using SRVCTL, Oracle
Enterprise Manager, and SQL*Plus
•
"Monitoring Oracle RAC and Oracle Clusterware"
•
"Server Control Utility Reference" for SRVCTL reference information
•
Oracle Clusterware Administration and Deployment Guide for information
about the Cluster Verification Utility (CVU), in addition to other Oracle
Clusterware tools, such as the OIFCFG tool for allocating and deallocating
network interfaces and the OCRCONFIG command-line tool for managing
OCR
•
Oracle Database Net Services Administrator's Guide for more information
about NETCA
1-36 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Managing Oracle RAC Environments
About Monitoring Oracle RAC Environments
Web-based Oracle Enterprise Manager Cloud Control enables you to monitor an
Oracle RAC database.
Oracle Enterprise Manager Cloud Control is a central point of control for the Oracle
environment that you access by way of a graphical user interface (GUI). See
"Monitoring Oracle RAC and Oracle Clusterware" and Oracle Database 2 Day + Real
Application Clusters Guide for detailed information about using Oracle Enterprise
Manager to monitor Oracle RAC environments.
Also, note the following recommendations about monitoring Oracle RAC
environments:
•
Use Oracle Enterprise Manager Cloud Control to initiate cluster database
management tasks.
•
Use Oracle Enterprise Manager Cloud Control to administer multiple or
individual Oracle RAC databases.
•
Use the global views (GV$ views), which are based on V$ views. The
catclustdb.sql script creates the GV$ views. Run this script if you do not
create your database with DBCA. Otherwise, DBCA runs this script for you.
For almost every V$ view, there is a corresponding global GV$ view. In addition
to the V$ information, each GV$ view contains an extra column named INST_ID,
which displays the instance number from which the associated V$ view
information was obtained.
•
Use the sophisticated management and monitoring features of the Oracle
Database Diagnostic and Tuning packs within Oracle Enterprise Manager that
include the Automatic Database Diagnostic Monitor (ADDM) and Automatic
Workload Repository (AWR).
Note:
Although Statspack is available for backward compatibility, Statspack
provides reporting only. You must run Statspack at level 7 to collect statistics
related to block contention and segment block waits.
Related Topics:
Monitoring Oracle RAC and Oracle Clusterware
Oracle Database 2 Day + Real Application Clusters Guide
Oracle Database Performance Tuning Guide
See Also:
Oracle Database Performance Tuning Guide for descriptions of the Oracle
Database automatic features for performance diagnosing and tuning,
including ADDM
Introduction to Oracle RAC 1-37
Overview of Managing Oracle RAC Environments
About Evaluating Performance in Oracle RAC Environments
You do not need to perform special tuning for Oracle RAC; Oracle RAC scales without
special configuration changes. If your application performs well on a noncluster
Oracle database, then it will perform well in an Oracle RAC environment. Many of the
tuning tasks that you would perform on a noncluster Oracle database can also
improve Oracle RAC database performance. This is especially true if your
environment requires scalability across a greater number of CPUs.
Some of the performance features specific to Oracle RAC include:
•
•
•
Dynamic resource allocation
–
Oracle Database dynamically allocates Cache Fusion resources as needed
–
The dynamic mastering of resources improves performance by keeping
resources local to data blocks
Cache Fusion enables a simplified tuning methodology
–
You do not have to tune any parameters for Cache Fusion
–
No application-level tuning is necessary
–
You can use a bottom-up tuning approach with virtually no effect on your
existing applications
More detailed performance statistics
–
More views for Oracle RAC performance monitoring
–
Oracle RAC-specific performance views in Oracle Enterprise Manager
1-38 Oracle Real Application Clusters Administration and Deployment Guide
2
Administering Storage in Oracle RAC
Oracle recommends Oracle Automatic Storage Management (Oracle ASM) as a storage
management solution that provides an alternative to conventional volume managers,
file systems, and raw devices.
Oracle ASM is a volume manager and a file system for Oracle database files that
supports single-instance Oracle Database and Oracle Real Application Clusters (Oracle
RAC) configurations.
Oracle ASM uses disk groups to store data files; an Oracle ASM disk group is a
collection of disks that Oracle ASM manages as a unit. Within a disk group, Oracle
ASM exposes a file system interface for Oracle database files. The content of files that
are stored in a disk group is evenly distributed to eliminate hot spots and to provide
uniform performance across the disks. The performance is comparable to the
performance of raw devices.
You can add or remove disks from a disk group while a database continues to access
files from the disk group. When you add or remove disks from a disk group, Oracle
ASM automatically redistributes the file contents and eliminates the need for
downtime when redistributing the content.
The Oracle ASM volume manager functionality provides flexible server-based
mirroring options. The Oracle ASM normal and high redundancy disk groups enable
two-way and three-way mirroring respectively. You can use external redundancy to
enable a Redundant Array of Independent Disks (RAID) storage subsystem to perform
the mirroring protection function.
Oracle ASM also uses the Oracle Managed Files feature to simplify database file
management. Oracle Managed Files automatically creates files in designated locations.
Oracle Managed Files also names files and removes them while relinquishing space
when tablespaces or files are deleted.
Oracle ASM reduces the administrative overhead for managing database storage by
consolidating data storage into a small number of disk groups. The smaller number of
disk groups consolidates the storage for multiple databases and dprovides for
improved I/O performance.
Oracle ASM files can coexist with other storage management options such as raw
disks and third-party file systems. This capability simplifies the integration of Oracle
ASM into pre-existing environments.
Oracle ASM has easy to use management interfaces such as SQL*Plus, the Oracle ASM
Command Line Utility (ASMCMD) command-line interface, and Oracle ASM
Configuration Assistant (ASMCA).
This chapter includes the following topics:
•
Overview of Storage Management for Oracle RAC
•
Data File Access in Oracle RAC
Administering Storage in Oracle RAC 2-1
Overview of Storage Management for Oracle RAC
•
NFS Server for Storage
•
Redo Log File Storage in Oracle RAC
•
Automatic Undo Management in Oracle RAC
•
Oracle Automatic Storage Management with Oracle RAC
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
Oracle Automatic Storage Management Administrator's Guide
Overview of Storage Management for Oracle RAC
All data files (including an undo tablespace for each instance) and redo log files (at
least two for each instance) for an Oracle RAC database must reside on shared storage.
Oracle recommends that you use Oracle ASM to store these files in an Oracle ASM
disk group.
Oracle supports alternative ways of using shared storage, such as certified cluster file
systems. In addition, Oracle recommends that you use one shared server parameter
file (SPFILE) with instance-specific entries. Oracle RAC 12c allows storing shared
password files in Oracle ASM and storing Oracle Database files on Oracle Automatic
Storage Management Cluster File System (Oracle ACFS).
Note:
Oracle Database and related technologies, such as Oracle Clusterware, no
longer support the use of raw (block) storage devices. You must move files to
Oracle ASM before upgrading to Oracle Clusterware 12c.
Unless otherwise noted, Oracle Database storage features such as Oracle ASM, Oracle
Managed Files, automatic segment-space management, and so on, function the same
in Oracle RAC environments as they do in noncluster Oracle database environments.
Note:
To create an Oracle RAC database using Oracle Database Standard Edition,
you must use Oracle ASM for your database storage.
Related Topics:
Oracle Database 2 Day DBA
Oracle Automatic Storage Management Administrator's Guide
Oracle Database Administrator’s Guide
Data File Access in Oracle RAC
All Oracle RAC instances must be able to access all data files. If a data file must be
recovered when the database is opened, then the first Oracle RAC instance to start is
the instance that performs the recovery and verifies access to the file. As other
2-2 Oracle Real Application Clusters Administration and Deployment Guide
NFS Server for Storage
instances start, they also verify their access to the data files. Similarly, when you add a
tablespace or data file or bring a tablespace or data file online, all instances verify
access to the file or files.
If you add a data file to a disk that other instances cannot access, then verification fails.
Verification also fails if instances access different copies of the same data file. If
verification fails for any instance, then diagnose and fix the problem. Then run the
ALTER SYSTEM CHECK DATAFILES statement on each instance to verify data file
access.
NFS Server for Storage
An Oracle database can serve as a network file system (NFS) server. The database
responds to NFS requests from any NFS client and stores both the files and their
metadata within the database.
Files associated with a primary database, such as SQL scripts, can be automatically
replicated on a standby database. You can also store unstructured data, such as emails,
on the database.
You can create or destroy an Oracle file system and access it though the NFS server
using the procedures documented in Oracle Database SecureFiles and Large Objects
Developer's Guide.
Related Topics:
Oracle Database SecureFiles and Large Objects Developer's Guide
Oracle Database PL/SQL Packages and Types Reference
Oracle Database Reference
Redo Log File Storage in Oracle RAC
In an Oracle RAC database, each instance must have at least two groups of redo log
files. You must allocate the redo log groups before enabling a new instance with the
ALTER DATABASE ENABLE INSTANCE instance_name command. When you use
DBCA to create the database, DBCA allocates redo log files to instances, as required,
automatically. You can change the number of redo log groups and the size of the redo
log files as required either during the initial database creation or as a post-creation
step.
When the current group fills, an instance begins writing to the next log file group. If
your database is in ARCHIVELOG mode, then each instance must save filled online log
groups as archived redo log files that are tracked in the control file. During database
recovery, all enabled instances are checked to see if recovery is needed. If you remove
an instance from your Oracle RAC database, then you should disable the instance's
thread of redo so that Oracle does not have to check the thread during database
recovery.
Redo log management must be considered when the number of instances for a
particular production Oracle RAC database changes. For example, if you increase the
cardinality of a server pool for a policy-managed database and a new server is
allocated to the server pool, then Oracle starts an instance on the new server. As soon
as the database instance on the new server starts, it will require a set of redo log
groups. Using Oracle Managed Files based on an Oracle ASM disk group, allocation of
the required redo log thread and respective files is performed automatically. You
should create redo log groups only if you use administrator-managed databases.
Administering Storage in Oracle RAC 2-3
Automatic Undo Management in Oracle RAC
For administrator-managed databases, each instance has its own online redo log
groups. Create these redo log groups and establish group members. To add a redo log
group to a specific instance, specify the INSTANCE clause in the ALTER DATABASE
ADD LOGFILE statement. If you do not specify the instance when adding the redo log
group, then the redo log group is added to the instance to which you are currently
connected.
Each instance must have at least two groups of redo log files. You must allocate the
redo log groups before enabling a new instance with the ALTER DATABASE ENABLE
INSTANCE instance_name command. When the current group fills, an instance
begins writing to the next log file group. If your database is in ARCHIVELOG mode,
then each instance must save filled online log groups as archived redo log files that are
tracked in the control file.
During database recovery, all enabled instances are checked to see if recovery is
needed. If you remove an instance from your Oracle RAC database, then you should
disable the instance's thread of redo so that Oracle does not have to check the thread
during database recovery.
Related Topics:
About Designing and Deploying Oracle RAC Environments
Any enterprise that is designing and implementing a high availability
strategy with Oracle RAC must begin by performing a thorough analysis
of the business drivers that require high availability.
Oracle Database Administrator’s Guide
Oracle Database SQL Language Reference
Automatic Undo Management in Oracle RAC
Oracle Database automatically manages undo segments within a specific undo
tablespace that is assigned to an instance. Instances can always read all undo blocks
throughout the cluster environment for consistent read purposes. Also, any instance
can update any undo tablespace during transaction recovery, if that undo tablespace is
not currently used by another instance for undo generation or transaction recovery.
You assign undo tablespaces in your Oracle RAC administrator-managed database by
specifying a different value for the UNDO_TABLESPACE parameter for each instance in
your SPFILE or individual PFILEs. For policy-managed databases, Oracle
automatically allocates the undo tablespace when the instance starts if you have
Oracle Managed Files enabled. You cannot simultaneously use automatic undo
management and manual undo management in an Oracle RAC database. In other
words, all instances of an Oracle RAC database must operate in the same undo mode.
Related Topics:
Setting SPFILE Parameter Values for Oracle RAC
Oracle Database Administrator’s Guide
Oracle Automatic Storage Management with Oracle RAC
Oracle ASM automatically maximizes I/O performance by managing the storage
configuration across the disks that Oracle ASM manages.
Oracle ASM does this by evenly distributing the database files across all of the
available storage assigned to the disk groups within Oracle ASM. Oracle ASM
2-4 Oracle Real Application Clusters Administration and Deployment Guide
Oracle Automatic Storage Management with Oracle RAC
allocates your total disk space requirements into uniformly sized units across all disks
in a disk group. Oracle ASM can also automatically mirror files to prevent data loss.
Because of these features, Oracle ASM also significantly reduces your administrative
overhead.
Oracle ASM instances are created on each node where you install Oracle Clusterware.
Each Oracle ASM instance has either an SPFILE or PFILE type parameter file. Oracle
recommends that you back up the parameter files and the TNS entries for nondefault
Oracle Net listeners.
To use Oracle ASM with Oracle RAC, select Oracle ASM as your storage option when
you create your database with the Database Configuration Assistant (DBCA). As in
noncluster Oracle databases, using Oracle ASM with Oracle RAC does not require I/O
tuning.
The following topics describe Oracle ASM and Oracle ASM administration, as follows:
•
Storage Management in Oracle RAC
•
Modifying Disk Group Configurations for Oracle ASM
•
Oracle ASM Disk Group Management
•
Configuring Preferred Mirror Read Disks in Extended Distance Clusters
•
Converting Nonclustered Oracle ASM to Clustered Oracle ASM
•
Administering Oracle ASM Instances with SRVCTL in Oracle RAC
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
Storage Management in Oracle RAC
You can create Oracle ASM disk groups and configure mirroring for Oracle ASM disk
groups using the Oracle ASM configuration assistant (ASMCA).
Alternatively, you can use Oracle Enterprise Manager to administer Oracle ASM disk
groups after you have discovered the respective servers with Oracle Enterprise
Manager.
The Oracle tools that you use to manage Oracle ASM, including ASMCA, Oracle
Enterprise Manager, and the silent mode install and upgrade commands, include
options to manage Oracle ASM instances and disk groups.
You can use the Cluster Verification Utility (CVU) to verify the integrity of Oracle
ASM across the cluster. Typically, this check ensures that the Oracle ASM instances on
all nodes run from the same Oracle home and, if asmlib exists, that it is a valid
version and has valid ownership. Run the following command to perform this check:
cluvfy comp asm [-n node_list] [-verbose]
Replace node_list with a comma-delimited list of node names on which the check is
to be performed. Specify all to check all nodes in the cluster.
Use the cluvfy comp ssa command to locate shared storage.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Administering Storage in Oracle RAC 2-5
Oracle Automatic Storage Management with Oracle RAC
Modifying Disk Group Configurations for Oracle ASM
When you create a disk group for a cluster or add new disks to an existing clustered
disk group, prepare the underlying physical storage on shared disks and give the
Oracle user permission to read and write to the disk.
The shared disk requirement is the only substantial difference between using Oracle
ASM with an Oracle RAC database compared to using it with a noncluster Oracle
database. Oracle ASM automatically redistributes the data files after you add or delete
a disk or disk group.
In a cluster, each Oracle ASM instance manages its node's metadata updates to the
disk groups. In addition, each Oracle ASM instance coordinates disk group metadata
with other nodes in the cluster. As with noncluster Oracle databases, you can use
Oracle Enterprise Manager, ASMCA, SQL*Plus, and the Server Control Utility
(SRVCTL) to administer disk groups for Oracle ASM that are used by Oracle RAC.
Oracle Automatic Storage Management Administrator's Guide explains how to use
SQL*Plus to administer Oracle ASM instances. Subsequent sections describe how to
use the other tools.
Note:
When you start ASMCA, if there is not an Oracle ASM instance, then the
utility prompts you to create one.
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
Oracle ASM Disk Group Management
To use Oracle ASM, you must first create disk groups with ASMCA before creating a
database with DBCA.
You can also use the disk group management commands to create and manage an
Oracle ASM instance and its associated disk groups independently of creating a
database. You can use Oracle Enterprise Manager or ASMCA to add disks to a disk
group, to mount a disk group or to mount all of the disk groups, or to create Oracle
ASM instances. Additionally, you can use Oracle Enterprise Manager to dismount and
drop disk groups or to delete Oracle ASM instances.
Oracle ASM instances are created when you install Oracle Clusterware. To create an
Oracle ASM disk group, run ASMCA from the Grid_home/bin directory. You can
also use the Oracle ASM Disk Groups page in ASMCA for Oracle ASM management.
That is, you can configure Oracle ASM storage separately from database creation. For
example, from the ASM Disk Groups page, you can create disk groups, add disks to
existing disk groups, or mount disk groups that are not currently mounted.
When you start ASMCA, if the Oracle ASM instance has not been created, then
ASMCA prompts you to create the instance. ASMCA prompts you for the sysasm
password and the ASMSNMP password.
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
2-6 Oracle Real Application Clusters Administration and Deployment Guide
Oracle Automatic Storage Management with Oracle RAC
Configuring Preferred Mirror Read Disks in Extended Distance Clusters
When you configure Oracle ASM failure groups, it may be more efficient for a node to
read from an extent that is closest to the node, even if that extent is a secondary extent.
You can configure Oracle ASM to read from a secondary extent if that extent is closer
to the node instead of Oracle ASM reading from the primary copy which might be
farther from the node. Using preferred read failure groups is most beneficial in an
extended distance cluster.
To configure this feature, set the ASM_PREFERRED_READ_FAILURE_GROUPS
initialization parameter to specify a list of failure group names as preferred read disks.
Oracle recommends that you configure at least one mirrored extent copy from a disk
that is local to a node in an extended cluster. However, a failure group that is
preferred for one instance might be remote to another instance in the same Oracle
RAC database. The parameter setting for preferred read failure groups is instance
specific.
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
Oracle Database Reference
Converting Nonclustered Oracle ASM to Clustered Oracle ASM
When installing Oracle Grid Infrastructure, any nonclustered Oracle ASM instances
are automatically converted to clustered Oracle ASM.
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Oracle Automatic Storage Management Administrator's Guide
Administering Oracle ASM Instances with SRVCTL in Oracle RAC
You can use the Server Control Utility (SRVCTL) to add or remove an Oracle ASM
instance.
To issue SRVCTL commands to manage Oracle ASM, log in as the operating system
user that owns the Oracle Grid Infrastructure home and issue the SRVCTL commands
from the bin directory of the Oracle Grid Infrastructure home.
Use the following syntax to add an Oracle ASM instance:
srvctl add asm
Use the following syntax to remove an Oracle ASM instance:
srvctl remove asm [-force]
You can also use SRVCTL to start, stop, and obtain the status of an Oracle ASM
instance as in the following examples.
Use the following syntax to start an Oracle ASM instance:
srvctl start asm [-node node_name] [-startoption start_options]
Use the following syntax to stop an Oracle ASM instance:
Administering Storage in Oracle RAC 2-7
Oracle Automatic Storage Management with Oracle RAC
srvctl stop asm [-node node_name] [-stopoption stop_options]
Use the following syntax to show the configuration of an Oracle ASM instance:
srvctl config asm -node node_name
Use the following syntax to display the state of an Oracle ASM instance:
srvctl status asm [-node node_name]
Related Topics:
Server Control Utility Reference
Oracle Automatic Storage Management Administrator's Guide
2-8 Oracle Real Application Clusters Administration and Deployment Guide
3
Administering Database Instances and
Cluster Databases
This chapter describes how to administer Oracle Real Application Clusters (Oracle
RAC) databases and database instances.
The topics in this chapter include:
•
Overview of Oracle RAC Database Administration
•
Starting and Stopping Instances and Oracle RAC Databases
•
Starting and Stopping PDBs in Oracle RAC
•
Verifying That Instances are Running
•
Terminating Sessions On a Specific Cluster Instance
•
Overview of Initialization Parameter Files in Oracle RAC
•
Initialization Parameter Use in Oracle RAC
•
Converting an Administrator-Managed Database to a Policy-Managed Database
•
Managing Memory Pressure for Database Servers
•
Quiescing Oracle RAC Databases
•
Administering Multiple Cluster Interconnects on Linux and UNIX Platforms
•
Customizing How Oracle Clusterware Manages Oracle RAC Databases
•
Advanced Oracle Enterprise Manager Administration
See Also:
The Oracle Enterprise Manager Cloud Control online help for more
information about Oracle Enterprise Manager Cloud Control
Overview of Oracle RAC Database Administration
Oracle RAC database administration requires certain privileges and involves either a
policy-managed or administrator-managed deployment model.
Required Privileges for Oracle RAC Database Administration
To increase security and further separate administrative duties, Oracle RAC database
administrators manage Oracle RAC databases with the SYSRAC administrative
privilege, and no longer require the SYSDBA administrative privilege. The SYSRAC
Administering Database Instances and Cluster Databases 3-1
Overview of Oracle RAC Database Administration
administrative privilege is the default mode of connecting to the database by the
Oracle Clusterware agent on behalf of Oracle RAC utilities, such as SRVCTL, meaning
that no SYSDBA connections to the database are necessary for everyday
administration of Oracle RAC database clusters.
Oracle RAC Database Depolyment Models
Oracle RAC databases support two different management styles and deployment
models:
•
Administrator-managed deployment is based on the Oracle RAC deployment
types that existed before Oracle Database 11g release 2 (11.2) and requires that you
statically configure each database instance to run on a specific node in the cluster,
and that you configure database services to run on specific instances belonging to
a certain database using the preferred and available designation.
•
Policy-managed deployment is based on server pools, where database services run
within a server pool as singleton or uniform across all of the servers in the server
pool. Databases are deployed in one or more server pools and the size of the
server pools determine the number of database instances in the deployment.
You can manage databases with either the administrator-managed or policy-managed
deployment model using the same commands or methods (such as DBCA or Oracle
Enterprise Manager). All commands and utilities maintain backward compatibility to
support the management of Oracle databases that only support administrator-based
management (Oracle databases before Oracle Database 11g release 2 (11.2)).
In general, a database is defined as a resource in Oracle Clusterware. The database
resource is automatically created when you create your database with DBCA or
provision a database using Rapid Home Provisioning, or you can manually create the
database resource by adding your database with SRVCTL. The database resource
contains the Oracle home, the SPFILE, one or more server pools, and one or more
Oracle ASM disk groups required for the database to start. You can specify the Oracle
ASM disk groups using either the srvctl add database or srvctl modify
database commands, or, when the database opens a data file on a disk group that is
not on this list, the disk group gets added to the list.
The database resource also has a weak start dependency on the listener type, which
means that the resource tries to start all listeners for the node when the database
instance starts. Oracle Clusterware tries to start listeners on the node where the
database instance starts. Starting the listeners in turn starts the VIP for the node.
When you review the database resource for an administrator-managed database, you
see a server pool defined with the same name as the Oracle database. This server pool
is part of a special Oracle-defined server pool called Generic. Oracle RAC manages the
Generic server pool to support administrator-managed databases. When you add or
remove an administrator-managed database using either SRVCTL or DBCA, Oracle
RAC creates or removes the server pools that are members of Generic. You cannot use
SRVCTL or CRSCTL commands to modify the Generic server pool.
Use policy-managed databases to simplify management of dynamic systems. Policy
management allows clusters and databases to expand or shrink as requirements
change. If you use policy-managed databases, then you must install the Oracle home
software on every node in your cluster. Policy-managed databases must use Oracle
Database 11g release 2 (11.2) or higher software and cannot coexist on the same servers
as administrator-managed databases.
3-2 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle RAC Database Administration
Note:
You cannot run more than one instance of the same database on the same
node.
A policy-managed database is defined by cardinality, which is the number of database
instances you want running during normal operations. A policy-managed database
runs in one or more database server pools that the cluster administrator creates in the
cluster, and it can run on different servers at different times. Every server pool of a
policy-managed database should have at least one database service. A database
instance starts on a server that is in the server pools defined for the database. If you
are using Oracle Automatic Storage Management (Oracle ASM) with Oracle Managed
Files for your database storage, then, when an instance starts and there is no redo
thread available, Oracle RAC automatically enables one and creates the required redo
log files and undo tablespace. Clients can connect to a policy-managed database using
the same SCAN-based connect string no matter which servers they happen to be
running on at the time.
Policy-managed databases are named db_unique_name_cardinality, where
cardinality is the cardinality ID of the server in the server pool. Use the srvctl
status database -sid command to retrieve the instance name on the local node.
You can also create a fixed mapping of nodes-to-instance name using the srvctl
modify instance command.
Using the Same Cluster for Administrator-Managed and Policy-Managed
Databases
If you want to create an administrator-managed database on a cluster that already
hosts policy-managed databases, then you must carefully select the nodes for the
administrator-managed database. This is because the nodes that you select for an
administrator-managed database that are in policy-managed server pools will be
moved into the Generic server pool as part of this process.
If you select nodes that already run other policy-managed database instances, then
DBCA prompts you with a message that lists the instances and services that will be
shut down when DBCA creates the administrator-managed database. If you select the
Yes button on the dialog box when DBCA asks "Do you want to continue?", then your
policy-managed database instances and services will be shut down because of the
administrator-managed database creation process.
Note:
This is also true if you use the srvctl add instance command, which
returns a similar error message indicating that the databases would be shut
down. If you also use the force option (-f) with the srvctl add instance
command, then this is the same as choosing Yes on the DBCA dialog. Doing
this shuts down any policy-managed databases that are running on the node
before moving the node into the Generic server pool.
Related Topics:
Oracle Database Security Guide
Oracle Clusterware Administration and Deployment Guide
Administering Database Instances and Cluster Databases 3-3
Overview of Oracle RAC Database Administration
Converting an Administrator-Managed Database to a Policy-Managed Database
You can convert an administrator-managed database to a policymanaged database.
Tools for Administering Oracle RAC
The following sections introduce Oracle RAC administration using the three tools that
you commonly use to manage Oracle RAC databases and instances: the SRVCTL
utility, Oracle Enterprise Manager, and SQL*Plus. In many cases, you use these tools
the same way to manage Oracle RAC environments as you would use them manage
noncluster Oracle databases:
•
Administering Oracle RAC with SRVCTL
•
Administering Oracle RAC with Oracle Enterprise Manager
•
Administering Oracle RAC with SQL*Plus
Administering Oracle RAC with SRVCTL
The Server Control Utility (SRVCTL) is a command-line interface that you can use to
manage Oracle Databases in a centralized manner.
Oracle made centralized, SRVCTL-based database management available in Oracle
Database 11g release 2 (11.2) for single-instance Oracle Databases, using Oracle ASM
in the Oracle Grid Infrastructure, for both a noncluster environment and Oracle RAC
databases, based on Oracle Grid Infrastructure for a cluster. This enables
homogeneous management of all Oracle Database types using SRVCTL. You can use
SRVCTL to start and stop the database and instances, and to delete or move instances
and services. You can also use SRVCTL to add services and manage configuration
information, in addition to other resources in the cluster.
When you use SRVCTL to perform configuration operations on your cluster, SRVCTL
stores configuration data in the Oracle Cluster Registry (OCR) in a cluster or Oracle
Local Registry (OLR) in Oracle Restart environments. SRVCTL performs other
operations, such as starting and stopping instances, by configuring and managing
Oracle Clusterware resources, which define agents that perform database startup and
shutdown operations using Oracle Call Interface APIs.
Note:
If you require your database (or database instance) to start using certain
environment variables, then use the srvctl setenv command to set those
variables for the database profile that is maintained for the database using
SRVCTL. You do not need to set the ORACLE_HOME and ORACLE_SID
environment variables, because SRVCTL maintains and sets those parameters,
automatically.
Related Topics:
Server Control Utility Reference
Administering Oracle RAC with Oracle Enterprise Manager
Oracle Enterprise Manager provides a central point of control for the Oracle RAC
environment, allowing you to perform administrative tasks simultaneously on
multiple cluster databases.
3-4 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Oracle RAC Database Administration
Based on the Oracle Enterprise Manager Cloud Control (Grid Control in Oracle
Enterprise Manager 11g) graphical user interface (GUI), you can manage both nonclustered and Oracle RAC environments.
In Oracle Enterprise Manager, Oracle RAC-specific administrative tasks generally
focus on two levels: tasks that affect an entire cluster database and tasks that affect
specific instances. For example, you can use Oracle Enterprise Manager to start, stop,
and monitor databases, cluster database instances, and their listeners, and to schedule
jobs or set up alert thresholds for metrics. Or you can perform instance-specific
commands such as setting parameters or creating resource plans. You can also use
Oracle Enterprise Manager to manage schemas, security, and cluster database storage
features.
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Advanced Oracle Enterprise Manager Administration
You can install, configure, and monitor an Oracle RAC database from a
single location using Oracle Enterprise Manager Cloud Control.
Administering Oracle RAC with SQL*Plus
Unlike SRVCTL or Oracle Enterprise Manager, SQL*Plus is an instance-oriented
management tool.
SQL*Plus commands operate on the current instance. The current instance can be
either the local default instance on which you initiated your SQL*Plus session, or it can
be a remote instance to which you connect with Oracle Net Services. For an Oracle
RAC environment that runs multiple instances on one database at the same time, this
implies that you need to consider the extent to which SQL*Plus can operate on this
instance. Due to those restrictions, you should not use SQL*Plus to manage policymanaged databases.
For example, when using pluggable databases (PDBs)—regardless of whether those
databases are managed in an administrator-managed or a policy-managed style—you
must consider that any alteration performed on the PDB using a SQL*Plus connection
will, by default, only affect the current instance. To make changes affecting all
instances that belong to the PDB, you must use the ALTER PLUGGABLE DATABASE
command with instance=all. When using PDBs you must connect, using a
dynamic database service (net_service_name), to an instance, as PDBs represent
themselves as dynamic database services associated with one or more instances of an
Oracle RAC database.
Because, by default, the SQL*Plus prompt does not identify the current instance, you
should direct your commands to the correct instance. Starting a SQL*Plus session and
connecting to the database without specifying an instance directs all SQL*Plus
commands to the local instance. In this case, the default instance is also the current
instance.
Since the SQL*Plus prompt does not identify the current instance by default, you
should direct your commands to the correct instance. Starting a SQL*Plus session and
connecting to the database without specifying an instance directs all SQL*Plus
commands to the local instance. In this case, the default instance is also the current
instance. To connect to a different instance in SQL*Plus, issue a new CONNECT
command and specify a remote instance net service name, as shown in the following
example, where password is the password:
Administering Database Instances and Cluster Databases 3-5
Overview of Oracle RAC Database Administration
CONNECT [email protected]_service_name
Enter password: password
Connecting as SYSOPER or SYSRAC enables you to perform privileged operations,
such as instance startup and shutdown. Multiple SQL*Plus sessions can connect to the
same instance at the same time. SQL*Plus automatically disconnects you from the first
instance whenever you connect to another one.
Note:
Use the SYSASM privilege instead of the SYSRAC privilege to connect to and
administer an Oracle ASM instance. If you use the SYSRAC privilege to
connect to an Oracle ASM instance, then Oracle Database writes warnings to
the alert log files because commands that run using the SYSRAC privilege on
an Oracle ASM instance are deprecated.
Related Topics:
Oracle Database Administrator’s Guide
Oracle Automatic Storage Management Administrator's Guide
Oracle Database Net Services Administrator's Guide
Oracle Database Administrator’s Guide
How SQL*Plus Commands Affect Instances
Most SQL statements affect the current instance. You can use SQL*Plus to start and
stop instances in the Oracle RAC database. You do not need to run SQL*Plus
commands as root on Linux and UNIX systems or as Administrator on Windows
systems. You need only the proper database account with the privileges that you
normally use for a noncluster Oracle database. Some examples of how SQL*Plus
commands affect instances are:
•
ALTER SYSTEM CHECKPOINT LOCAL affects only the instance to which you are
currently connected, rather than the default instance or all instances.
•
ALTER SYSTEM CHECKPOINT or ALTER SYSTEM CHECKPOINT GLOBAL affects
all instances in the cluster database.
•
ALTER SYSTEM SWITCH LOGFILE affects only the current instance.
–
To force a global log switch, use the ALTER SYSTEM ARCHIVE LOG
CURRENT statement.
–
The INSTANCE option of ALTER SYSTEM ARCHIVE LOG enables you to
archive each online redo log file for a specific instance.
Table 3-1 describes how SQL*Plus commands affect instances.
Table 3-1
How SQL*Plus Commands Affect Instances
SQL*Plus Command
ARCHIVE LOG
Associated Instance
Always affects the current instance.
3-6 Oracle Real Application Clusters Administration and Deployment Guide
Starting and Stopping Instances and Oracle RAC Databases
Table 3-1
(Cont.) How SQL*Plus Commands Affect Instances
SQL*Plus Command
Associated Instance
CONNECT
Affects the default instance if no instance is specified in the
CONNECT command.
HOST
Affects the node running the SQL*Plus session, regardless of the
location of the current and default instances.
RECOVER
SHOW INSTANCE
SHOW PARAMETER
Does not affect any particular instance, but rather the database.
Displays information about the current instance, which can be
different from the default local instance if you have redirected your
commands to a remote instance.
Displays parameter and SGA information from the current instance.
and
SHOW SGA
STARTUP
Always affects the current instance. These are privileged SQL*Plus
commands.
and
SHUTDOWN
Starting and Stopping Instances and Oracle RAC Databases
You can start and stop instances with Oracle Enterprise Manager, SQL*Plus, or
SRVCTL.
Both Oracle Enterprise Manager and SRVCTL provide options to start and stop all of
the instances in an Oracle RAC database with a single step.
Using any tool, you can choose the startup state to which you want to start the
database. The state of the database and database instance will determine what
operations you can perform. You can perform certain operations only when the
database is in the MOUNT (NOMOUNT) state. Performing other operations requires
that the database be in the OPEN state.
Note:
Oracle does not support running more than one instance of the same database
on the same node.
To start an Oracle RAC database instance on a node in the cluster, you must first start
the Oracle Grid Infrastructure stack on the node. An Oracle RAC database instance
will not start on a server on which the Oracle Grid Infrastructure stack is not running.
Administering Database Instances and Cluster Databases 3-7
Starting and Stopping Instances and Oracle RAC Databases
Oracle Database QoS Management Policy Workload Criticality Determines
Database Startup Order
If a user-created Oracle Database Quality of Service Management (Oracle Database
QoS Management) policy is active, then the ranked order of the performance classes
determines the order in which the associated Oracle RAC databases start or request
real-time LMS process slots. Using the performance class rankings ensures that
mission-critical databases running in a consolidated environment have their LMS
processes run in real time, thus eliminating a resource bottleneck within inter-node
communication. Because the Oracle Database QoS Management policy specifies the
rank of each workload, using the value of Max(Ranks) for each database provides a
consistent expression of the expressed business criticality of each database.
The procedures in the following sections discuss starting and stopping Oracle RAC
database instances:
•
Starting One or More Instances and Oracle RAC Databases Using SRVCTL
•
Stopping One or More Instances and Oracle RAC Databases Using SRVCTL
•
Stopping All Databases and Instances Using CRSCTL
•
Starting and Stopping Individual Instances Using SQL*Plus
Related Topics:
Oracle Database Concepts
Oracle Database 2 Day + Real Application Clusters Guide
Starting One or More Instances and Oracle RAC Databases Using SRVCTL
Use SRVCTL start Oracle RAC databases and instances.
Note:
This section assumes that you are using an SPFILE for your database.
Enter the following SRVCTL syntax from the command line, providing the required
database name and instance name, or include multiple instance names to start
multiple specific instances:
•
To start or stop your entire cluster database, that is, all of the instances and its
enabled services, enter the following SRVCTL commands:
$ srvctl start database -db db_unique_name [-startoption start_options]
$ srvctl stop database -db db_unique_name [-o stop_options]
The following SRVCTL command, for example, mounts all of the non-running
instances of an Oracle RAC database:
$ srvctl start database -db orcl -startoption mount
•
To start administrator-managed databases, enter a comma-delimited list of
instance names:
$ srvctl start instance -db db_unique_name -instance instance_name_list
[-startoption start_options]
3-8 Oracle Real Application Clusters Administration and Deployment Guide
Starting and Stopping Instances and Oracle RAC Databases
In Windows you must enclose a comma-delimited list in double quotation marks
("").
•
To start policy-managed databases, enter a single node name:
$ srvctl start instance -db db_unique_name -node node_name
[-startoption start_options]
Note that this command also starts all enabled and non-running services that have
AUTOMATIC management policy, and for which the database role matches one of
the service's roles.
•
To stop one or more instances, enter the following SRVCTL syntax from the
command line:
$ srvctl stop instance -db db_unique_name [-instance "instance_name_list" |
-node node_name] [-stopoption stop_options]
You can enter either a comma-delimited list of instance names to stop several
instances or you can enter a node name to stop one instance. In Windows you
must enclose a comma-delimited list in double quotation marks ("").
This command also stops the services related to the terminated instances on the nodes
where the instances were running. As an example, the following command shuts
down the two instances, orcl3 and orcl4, on the orcl database using the
immediate stop option:
$ srvctl stop instance -db orcl -instance "orcl3,orcl4" -stopoption immediate
Related Topics:
Server Control Utility Reference
Stopping One or More Instances and Oracle RAC Databases Using SRVCTL
Use SRVCTL to stop instances and Oracle RAC databases.
The procedure for shutting down Oracle RAC instances is identical to shutting down
instances in noncluster Oracle databases, with the following exceptions:
•
In Oracle RAC, shutting down one instance does not interfere with the operation
of other running instances.
•
To shut down an Oracle RAC database completely, shut down every instance that
has the database open or mounted.
•
After a NORMAL or IMMEDIATE shutdown, instance recovery is not required.
Recovery is required, however, after you issue the SHUTDOWN ABORT command
or after an instance terminates abnormally. An instance that is still running
performs instance recovery for the instance that shut down. If no other instances
are running, the next instance to open the database performs instance recovery for
any instances needing it.
•
Using the SHUTDOWN TRANSACTIONAL command with the LOCAL option is
useful to shut down a particular Oracle RAC database instance. Transactions on
other instances do not block this operation. If you omit the LOCAL option, then
this operation waits until transactions on all other instances that started before
you ran the SHUTDOWN command either commit or rollback, which is a valid
approach, if you intend to shut down all instances of an Oracle RAC database.
Administering Database Instances and Cluster Databases 3-9
Starting and Stopping Instances and Oracle RAC Databases
Note:
SHUTDOWN TRANSACTIONAL and SHUTDOWN TRANSACTIONAL LOCAL both
perform the same action on a nonclustered database but the two commands
are different on an Oracle RAC database.
Use SRVCTL to shut down an Oracle RAC database or database instance. The
respective SRVCTL commands (srvctl stop database or srvctl stop
instance) provide shutdown options to perform an optimized transactional
shutdown. Use the TRANSACTIONAL stop option with the srvctl stop database
command and the TRANSACTIONAL LOCAL stop option with the srvctl stop
instance command.
Related Topics:
srvctl stop database
The srvctl stop database command stops a database, its instances,
and its services.
srvctl stop instance
The srvctl stop instance command stops instances and stops any
services running on specified instances.
Oracle Database Concepts
Oracle Database Administrator’s Guide
Stopping All Databases and Instances Using CRSCTL
When you want to stop an entire node or cluster (for maintenance purposes, for
example), you run either the crsctl stop crs command on the node or the
crsctl stop cluster -all command, provided you have the required cluster
privileges. These commands stop all database instances running on a server or in the
cluster and ensure that their state is recovered after you restart the cluster. Using
CRSCTL also enables Oracle Clusterware to relocate services and other resources that
can run elsewhere.
Using either of these CRSCTL commands to stop all database instances on a server or
in the cluster can lead to the database instances being stopped similar to shutdown
abort, which requires an instance recovery on startup. If you use SRVCTL to stop the
database instances manually before stopping the cluster, then you can prevent a
shutdown abort, but this requires that you manually restart the database instances after
restarting Oracle Clusterware.
Starting and Stopping Individual Instances Using SQL*Plus
If you want to start or stop just one instance and you are connected to your local node,
then you must first ensure that your current environment includes the SID for the local
instance.
Note that any subsequent commands in your session, whether inside or outside a
SQL*Plus session, are associated with that same SID.
Note:
This section assumes you are using an SPFILE.
3-10 Oracle Real Application Clusters Administration and Deployment Guide
Starting and Stopping Instances and Oracle RAC Databases
To start or shutdown your local instance, initiate a SQL*Plus session and connect with
the SYSRAC or SYSOPER privilege and then issue the required command. For
example to start and mount an instance on your local node, run the following
commands in your SQL*Plus session:
CONNECT / AS SYSRAC
STARTUP MOUNT
Note:
If you use Oracle ASM disk groups, then use the SYSASM privilege instead of
the SYSRAC privilege to connect to and administer the Oracle ASM instances.
Oracle recommends that you do not use SQL*Plus to manage Oracle ASM
instances in an Oracle RAC environment. Oracle Clusterware automatically
manages Oracle ASM instances, as required. If manual intervention is
necessary, then use respective SRVCTL commands.
You can start multiple instances from a single SQL*Plus session on one node using
Oracle Net Services. Connect to each instance in turn by using a Net Services
connection string, typically an instance-specific alias from your tnsnames.ora file.
For example, you can use a SQL*Plus session on a local node to perform a
transactional shutdown for two instances on remote nodes by connecting to each in
turn using the instance's individual alias name. Assume the alias name for the first
instance is db1 and that the alias for the second instance is db2. Connect to the first
instance and shut it down as follows:
CONNECT /@db1 AS SYSRAC
SHUTDOWN TRANSACTIONAL
Note:
To ensure that you connect to the correct instance, you must use an alias in the
connect string that is associated with just one instance. If you use a connect
string that uses a TNS alias that connects to a service or an Oracle Net address
that lists multiple IP addresses, then you might not be connected to the
specific instance you want to shut down.
Then connect to and shutdown the second instance by entering the following from
your SQL*Plus session:
CONNECT /@db2 AS SYSRAC
SHUTDOWN TRANSACTIONAL
It is not possible to start or stop multiple instances, simultaneously, with SQL*Plus, so
you cannot start or stop all of the instances for a cluster database with a single
SQL*Plus command. You may want to create a script that connects to each instance in
turn and start it up and shut it down. However, you must maintain this script
manually if you add or drop instances.
Related Topics:
Oracle Automatic Storage Management Administrator's Guide
SQL*Plus User's Guide and Reference
Administering Database Instances and Cluster Databases 3-11
Starting and Stopping PDBs in Oracle RAC
Starting and Stopping PDBs in Oracle RAC
Administering a pluggable database (PDB) involves a small subset of the tasks
required to administer a non-CDB.
Administering an Oracle RAC-based multitenant container database (CDB) is
somewhat similar to administering a non-CDB. The differences are only that some
administrative tasks apply to the entire CDB, some apply only to the root, and some
apply to specific pluggable databases (PDBs). In this subset of tasks, most are the same
for a PDB and a non-CDB. There are some differences, however, such as when you
modify the open mode of a PDB. Also, a PDB administrator is limited to managing a
single PDB and is not affected by other PDBs in the CDB.
See Also:
Oracle Database Administrator's Guide for more information about managing
CDBs and PDBs
You manage PDBs in an Oracle RAC-based CDB by managing services, regardless of
whether the PDBs are policy managed or administrator managed. Assign one dynamic
database service to each PDB to coordinate start, stop, and placement of PDBs across
instances in a clustered container database.
For example, if you have a CDB called raccont with a policy-managed PDB called
spark, which is in a server pool called prod, then assign a service called plug to this
database using the following command:
srvctl add service –db raccont –pdb spark –service plug –serverpool prod
The service plug will be uniformly managed across all nodes in the server pool. If you
want to have this service running as a singleton service in the same server pool, use
the -cardinality singleton parameter with the preceding command.
To open the PDB spark, you must start the respective service, plug, as follows:
srvctl start service -db raccont -service plug
To stop the service, plug:
srvctl stop service -db raccont -service plug
The PDB spark remains open until you close the PDB using the SQL command
ALTER PLUGGABLE DATABASE PDB_NAME CLOSE IMMEDIATE;. You can check
the status of the database using the srvctl status service command.
Because PDBs are managed using dynamic database services, typical Oracle RACbased management practices apply. So, if the service plug is in the ONLINE state
when Oracle Clusterware is shut down on a server hosting this service, then the
service will be restored to its original state after the restart of Oracle Clusterware on
this server. This way, starting PDBs is automated as with any other Oracle RAC
database.
3-12 Oracle Real Application Clusters Administration and Deployment Guide
Verifying That Instances are Running
Note:
Unlike SQL*Plus, SRVCTL operates on a cluster database, as a whole. Starting
a PDB using services therefore applies to multiple instances of the clustered
CDB at the same time, if the service is defined to run on multiple servers
simultaneously, and the current status of the cluster allows for this placement.
Related Topics:
Workload Management with Dynamic Database Services
Verifying That Instances are Running
To verify that a database instance is available, use Oracle Enterprise Manager,
SRVCTL, or SQL*Plus.
•
Using SRVCTL to Verify That Instances are Running
•
Using SQL*Plus to Verify That Instances are Running
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
See Also:
Oracle Database 2 Day + Real Application Clusters Guide for information about
using Oracle Enterprise Manager to view the status of Oracle RAC database
instances
Using SRVCTL to Verify That Instances are Running
You can use SRVCTL to verify that instances are running on a particular database.
The following command provides an example of using SRVCTL to check the status of
the database instances for the Oracle RAC database named mail:
$ srvctl status database -db mail
This command returns output similar to the following:
Instance mail1 is running on node betal011Instance mail2 is running on node betal010
Additionally, you can check whether PDBs are running in the cluster by checking the
availability of their assigned services, as follows:
$ srvctl status service -db db_unique_name -service service_name
Using SQL*Plus to Verify That Instances are Running
You can use SQL*Plus to verify that database instances are running.
1.
On any node, from a SQL*Plus prompt, connect to a database instance by using a
Net Services connection string, typically an instance-specific alias from your
tnsnames.ora file.
Administering Database Instances and Cluster Databases 3-13
Terminating Sessions On a Specific Cluster Instance
CONNECT /@db1 as SYSRAC
2.
Query the V$ACTIVE_INSTANCES view, using the following statement:
CONNECT SYS/as SYSRAC
Enter password: password
SELECT * FROM V$ACTIVE_INSTANCES;
This query returns output similar to the following:
INST_NUMBER
----------1
2
3
INST_NAME
----------------db1-sun:db1
db2-sun:db2
db3-sun:db3
The output columns for this example are shown in the following table.
Table 3-2
Descriptions of V$ACTIVE_INSTANCES Columns
Column
Description
INST_NUMBER
Identifies the instance number.
INST_NAME
Identifies the host name and instance name as
host_name:instance_name.
Terminating Sessions On a Specific Cluster Instance
You can use the ALTER SYSTEM KILL SESSION statement to terminate a session on
a specific instance.
When a session is terminated, any session active transactions are rolled back, and
resources held by the session (such as locks and memory areas) are immediately
released and available to other sessions.
Using the ALTER SYSTEM KILL SESSION statement enables you to maintain strict
application service-level agreements in Oracle RAC environments. Often, the goal of a
service-level agreement is to carry out a transaction in a specified time limit. In an
Oracle RAC environment, this may require terminating a transaction on an instance,
and retrying the transaction on another instance within a specified time frame.
Note:
You can use Application Continuity to hide the cancellation of a transaction
from the user, if the application initially used an Application Continuityenabled dynamic database service to connect to the database instance.
For a more granular approach to service-level management, Oracle
recommends that you use Oracle Database Quality of Service Management
(Oracle Database QoS Management) for all Oracle RAC-based databases.
To terminate sessions, follow these steps:
1.
Query the value of the INST_ID column in the GV$SESSION dynamic
performance view to identify which session to terminate.
3-14 Oracle Real Application Clusters Administration and Deployment Guide
Terminating Sessions On a Specific Cluster Instance
2.
Issue the ALTER SYSTEM KILL SESSION and specify the session index number
(SID) and serial number of a session that you identified with the GV$SESSION
dynamic performance view.
KILL SESSION 'integer1, integer2[, @integer3]'
•
For integer1, specify the value of the SID column.
•
For integer2, specify the value of the SERIAL# column.
•
For the optional integer3, specify the ID of the instance where the session
to be killed exists. You can find the instance ID by querying the GV$ tables.
To use this statement, your instance must have the database open, and your
session and the session to be terminated must be on the same instance unless you
specify integer3.
If the session is performing some activity that must be completed, such as waiting for
a reply from a remote database or rolling back a transaction, then Oracle Database
waits for this activity to complete, marks the session as terminated, and then returns
control to you. If the waiting lasts a minute, then Oracle Database marks the session to
be terminated and returns control to you with a message that the session is marked to
be terminated. The PMON background process then marks the session as terminated
when the activity is complete.
Examples of Identifying and Terminating Sessions
The following examples provide three scenarios in which a user identifies and
terminates a specific session. In each example, the SYSDBA first queries the GV
$SESSION view for the SCOTT user's session to identify the session to terminate, and
then runs the ALTER SYSTEM KILL SESSION statement to terminate the session on
the instance.
Example 3-1
Identify and terminate the session on an busy instance
In this example, assume that the executing session is SYSDBA on the instance
INST_ID=1. The ORA-00031 message is returned because some activity must be
completed before the session can be terminated.
SQL> SELECT SID, SERIAL#, INST_ID FROM GV$SESSION WHERE USERNAME='SCOTT';
SID
SERIAL#
INST_ID
---------- ---------- ---------80
4
2
SQL> ALTER SYSTEM KILL SESSION '80, 4, @2';
alter system kill session '80, 4, @2'
*
ERROR at line 1:
ORA-00031: session marked for kill
SQL>
Example 3-2
Identify and terminate the session on an idle instance
In this example, assume that the executing session is SYSDBA on the instance
INST_ID=1. The session on instance INST_ID=2 is terminated immediately when
Oracle Database executes the statement within 60 seconds.
SQL> SELECT SID, SERIAL#, INST_ID FROM GV$SESSION WHERE USERNAME='SCOTT';
SID
SERIAL#
INST_ID
Administering Database Instances and Cluster Databases 3-15
Overview of Initialization Parameter Files in Oracle RAC
---------- ---------- ---------80
6
2
SQL> ALTER SYSTEM KILL SESSION '80, 6, @2';
System altered.
SQL>
Example 3-3
Using the IMMEDIATE parameter
The following example includes the optional IMMEDIATE clause to immediately
terminate the session without waiting for outstanding activity to complete.
SQL> SELECT SID, SERIAL#, INST_ID FROM GV$SESSION WHERE USERNAME='SCOTT';
SID
SERIAL#
INST_ID
---------- ---------- ---------80
8
2
SQL> ALTER SYSTEM KILL SESSION '80, 8, @2' IMMEDIATE;
System altered.
SQL>
Related Topics:
Oracle Database Administrator’s Guide
Oracle Database 2 Day + Performance Tuning Guide
Oracle Database Quality of Service Management User's Guide
About Application Continuity
Application Continuity masks many recoverable database outages
(when replay is successful) from applications and users by restoring the
database session: the full session, including all states, cursors, variables,
and the last transaction if there is one.
Overview of Initialization Parameter Files in Oracle RAC
When you create the database, Oracle Database creates an SPFILE in the file location
that you specify. This location can be either an Oracle ASM disk group or a cluster file
system. If you manually create your database, then Oracle recommends that you
create an SPFILE from an initialization parameter file (PFILE).
Note:
Oracle RAC uses a traditional PFILE only if an SPFILE does not exist or if you
specify PFILE in your STARTUP command. Oracle recommends that you use
an SPFILE to simplify administration, to maintain parameter setting
consistency, and to guarantee parameter setting persistence across database
shutdown and startup events. In addition, you can configure RMAN to back
up your SPFILE.
All instances in the cluster database use the same SPFILE at startup. Because the
SPFILE is a binary file, do not directly edit the SPFILE with an editor. Instead, change
3-16 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Initialization Parameter Files in Oracle RAC
SPFILE parameter settings using Oracle Enterprise Manager or ALTER SYSTEM SQL
statements.
When creating an SPFILE, if you include the FROM MEMORY clause (for example,
CREATE PFILE FROM MEMORY or CREATE SPFILE FROM MEMORY), then the
CREATE statement creates a PFILE or SPFILE using the current system-wide parameter
settings. In an Oracle RAC environment, the created file contains the parameter
settings from each instance. Because the FROM MEMORY clause requires all other
instances to send their parameter settings to the instance that is trying to create the
parameter file, the total execution time depends on the number of instances, the
number of parameter settings on each instance, and the amount of data for these
settings.
This section includes the following topics:
•
Setting SPFILE Parameter Values for Oracle RAC
•
Parameter File Search Order in Oracle RAC
•
Backing Up the Server Parameter File
Setting SPFILE Parameter Values for Oracle RAC
You can change SPFILE settings with Oracle Enterprise Manager or by using the SET
clause of the ALTER SYSTEM statement.
Note:
Modifying the SPFILE using tools other than Oracle Enterprise Manager or
SQL*Plus can corrupt the file and prevent database startup. To repair the file,
you might be required to create a PFILE and then regenerate the SPFILE.
The examples in this section appear in ASCII text although the SPFILE is a binary file.
Assume that you start an instance with an SPFILE containing the following entries:
*.OPEN_CURSORS=500
prod1.OPEN_CURSORS=1000
The value before the period (.) in an SPFILE entry identifies the instance to which the
particular parameter value belongs. When an asterisk (*) precedes the period, the
value is applied to all instances that do not have a subsequent, individual value listed
in the SPFILE.
For the instance with the Oracle system identifier (SID) prod1, the OPEN_CURSORS
parameter is set to 1000 even though it has a database-wide setting of 500. Parameter
file entries that have the asterisk (*) wildcard character only affect the instances
without an instance-specific entry. This gives you control over parameter settings for
instance prod1. These two types of settings can appear in any order in the parameter
file.
If another DBA runs the following statement, then Oracle Database updates the setting
on all instances except the instance with SID prod1:
ALTER SYSTEM SET OPEN_CURSORS=1500 sid='*' SCOPE=SPFILE;
The SPFILE now has the following entries for OPEN_CURSORS:
Administering Database Instances and Cluster Databases 3-17
Overview of Initialization Parameter Files in Oracle RAC
*.OPEN_CURSORS=1500
prod1.OPEN_CURSORS=1000
Run the following statement to reset OPEN_CURSORS to its default value for all
instances except prod1:
ALTER SYSTEM RESET OPEN_CURSORS SCOPE=SPFILE;
The SPFILE now has just the following entry for prod1:
prod1.OPEN_CURSORS=1000
Run the following statement to reset the OPEN_CURSORS parameter to its default
value for instance prod1 only:
ALTER SYSTEM RESET OPEN_CURSORS SCOPE=SPFILE SID='prod1';
Parameter File Search Order in Oracle RAC
Oracle Database searches for your parameter file in a particular order depending on
your platform. For Oracle RAC databases, you can easily determine the location of the
parameter file by using the srvctl config database command.
On Linux and UNIX platforms, the search order is as follows:
1.
$ORACLE_HOME/dbs/spfilesid.ora
2.
$ORACLE_HOME/dbs/spfile.ora
3.
$ORACLE_HOME/dbs/initsid.ora
On Windows platforms, the search order is as follows:
1.
%ORACLE_HOME%\database\spfilesid.ora
2.
%ORACLE_HOME%\database\spfile.ora
3.
%ORACLE_HOME%\database\initsid.ora
Note:
Oracle recommends that you do not use the default SPFILE names because all
instances must use the same file and they all have different SIDs. Instead, store
the SPFILE on Oracle ASM. If you store the SPFILE on a cluster file system,
then use the following naming convention for the SPFILE:
$ORACLE_HOME/dbs/spfiledb_unique_name.ora. Create a PFILE
named $ORACLE_HOME/dbs/initsid.ora that contains the name
SPFILE=ORACLE_HOME/dbs/spfiledb_unique_name.ora.
Related Topics:
srvctl config database
Displays the configuration for an Oracle RAC database or lists all
configured databases that are registered with Oracle Clusterware.
Backing Up the Server Parameter File
Oracle recommends that you regularly back up the server parameter file for recovery
purposes.
3-18 Oracle Real Application Clusters Administration and Deployment Guide
Initialization Parameter Use in Oracle RAC
Do this using Oracle Enterprise Manager (as described in the Oracle Database 2 Day +
Real Application Clusters Guide) or use the CREATE PFILE statement. For example:
CREATE PFILE='/u01/oracle/dbs/test_init.ora'
FROM SPFILE='/u01/oracle/dbs/test_spfile.ora';
You can use Recovery Manager (RMAN) to create backups of the server parameter
file. You can also recover an SPFILE by starting an instance using a client-side
initialization parameter file. Then re-create the server parameter file using the CREATE
SPFILE statement. Note that if the parameter file that you use for this operation was
for a single instance, then the parameter file does not contain instance-specific values,
even those that must be unique in Oracle RAC instances. Therefore, ensure that your
parameter file contains the appropriate settings as described earlier in this chapter.
To ensure that your SPFILE (and control files) are automatically backed up by RMAN
during typical backup operations, use Oracle Enterprise Manager or the RMAN
CONTROLFILE AUTOBACKUP statement to enable the RMAN autobackup feature
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Oracle Database SQL Language Reference
Oracle Database Backup and Recovery Reference
Initialization Parameter Use in Oracle RAC
By default, most parameters are set to a default value and this value is the same across
all instances.
However, many initialization parameters can also have different values on different
instances as described in Table 3-3. Other parameters must either be unique or
identical as described in the following sections
•
Parameters That Must Have Identical Settings on All Instances
•
Parameters That Have Unique Settings on All Instances
•
Parameters That Should Have Identical Settings on All Instances
Table 3-3 summarizes the initialization parameters used specifically for Oracle RAC
databases.
Table 3-3
Initialization Parameters Specific to Oracle RAC
Parameter
Description
ACTIVE_INSTANCE_COUNT
This initialization parameter was deprecated in Oracle RAC 11g release 2 (11.2).
Instead, use a service with one preferred and one available instance.
ASM_PREFERRED_READ_FAI
LURE_GROUPS
Specifies a set of disks to be the preferred disks from which to read mirror data
copies. The values you set for this parameter are instance specific and need not
be the same on all instances.
CLUSTER_DATABASE
Enables a database to be started in cluster mode. Set this parameter to TRUE.
Administering Database Instances and Cluster Databases 3-19
Initialization Parameter Use in Oracle RAC
Table 3-3
(Cont.) Initialization Parameters Specific to Oracle RAC
Parameter
Description
CLUSTER_DATABASE_INSTA
NCES
Oracle RAC uses this parameter to allocate adequate memory resources. It must
be set to the same value on all instances.
•
•
For policy-managed databases, Oracle internally sets this parameter to 16
For administrator-managed databases, Oracle internally sets it to the
number of configured Oracle RAC instances
You can set this parameter to a value that is greater than the current number of
instances, if you are planning to add instances. For policy-managed databases,
you should set this parameter to a higher value only if you intend to run a
database with more than 16 instances. In this case, set the parameter to the
expected maximum number of instances on which this database will run.
CLUSTER_INTERCONNECTS
Specifies an alternative cluster interconnect for the private network when there
are multiple interconnects.
Notes:
•
•
•
Oracle recommends that all Oracle databases and Oracle Clusterware use
the same interconnect network.
Oracle does not recommend setting the CLUSTER_INTERCONNECTS
parameter except in certain situations. See "Administering Multiple Cluster
Interconnects on Linux and UNIX Platforms" for more details.
This parameter is stored in the Grid Plug and Play profile in a Grid Plug
and Play environment.
DB_NAME
If you set a value for DB_NAME in instance-specific parameter files, the setting
must be identical for all instances.
DISPATCHERS
Set the DISPATCHERS parameter to enable a shared server configuration, that is
a server that is configured to enable many user processes to share very few
server processes. With shared server configurations, many user processes
connect to a dispatcher. The DISPATCHERS parameter may contain many
attributes.
Oracle recommends that you configure at least the PROTOCOL and LISTENER
attributes. PROTOCOL specifies the network protocol for which the dispatcher
process generates a listening end point. LISTENER specifies an alias name for
the Oracle Net Services listeners. Set the alias to a name that is resolved through
a naming method such as a tnsnames.ora file. The tnsnames.ora file
contains net service names. Clients, nodes, and the Oracle Performance Manager
node need this file. Oracle Enterprise Manager does not require tnsnames.ora
entries on the client for Cloud Control.
See Also: Oracle Database Net Services Administrator's Guide for complete
information about configuring the DISPATCHERS parameter and its attributes
and for configuring the shared server
GCS_SERVER_PROCESSES
This static parameter specifies the initial number of server processes for an
Oracle RAC instance's Global Cache Service (GCS). The GCS processes manage
the routing of interinstance traffic among Oracle RAC instances. The default
number of GCS server processes is calculated based on system resources with a
minimum setting of 2. For systems with one CPU, there is one GCS server
process. For systems with two to eight CPUs, there are two GCS server
processes. For systems with more than eight CPUs, the number of GCS server
processes equals the number of CPUs divided by 4, dropping any fractions. For
example, if you have 10 CPUs, then 10 divided by 4 means that your system has
2 GCS processes. You can set this parameter to different values on different
instances.
3-20 Oracle Real Application Clusters Administration and Deployment Guide
Initialization Parameter Use in Oracle RAC
Table 3-3
(Cont.) Initialization Parameters Specific to Oracle RAC
Parameter
Description
INSTANCE_NAME
Specifies the unique name of an instance. Clients can use this name to force their
session to be connected to a specific instance in the cluster. The format of the
INSTANCE_NAME parameter is generally
db_unique_name_instance_number, such as orcldb_2.
Note: In Grid Plug and Play environments, the INSTANCE_NAME parameter is
not required and defaults to db_unique_name_instance_number if not
specified.
RESULT_CACHE_MAX_SIZE
In a clustered database, you can either set RESULT_CACHE_MAX_SIZE=0 on
every instance to disable the result cache, or use a nonzero value on every
instance to enable the result cache. To switch between enabled and disabled
result cache requires that you restart every instance:
•
Enabling the result cache: Set RESULT_CACHE_MAX_SIZE to a value
greater than 0, or leave the parameter unset. You can size the cache
differently on individual instances.
•
Disabling the result cache: Set RESULT_CACHE_MAX_SIZE=0 on all
instances to disable the result cache. If you set
RESULT_CACHE_MAX_SIZE=0 upon startup of any one instance, then you
must set the parameter to zero on all instance startups because disabling
the result cache must done clusterwide. Disabling the result cache on some
instances may lead to incorrect results.
If you do not set the RESULT_CACHE_MAX_SIZE parameter, the parameter
resolves to a default, nonzero value.
SERVICE_NAMES
When you use services, Oracle recommends that you do not set a value for the
SERVICE_NAMES parameter but instead you should create cluster managed
services through the Cluster Managed Services page in Oracle Enterprise
Manager Cloud Control. This is because Oracle Clusterware controls the setting
for this parameter for the services that you create and for the default database
service. The service features described in Workload Management with Dynamic
Database Services are not directly related to the features that Oracle provides
when you set SERVICE_NAMES. In addition, setting a value for this parameter
may override some benefits of using services.
Note: Oracle recommends that client connections use services rather than
instance names. Entries in the SERVICE_NAMES parameter may be used by
client connections rather than the INSTANCE_NAME parameter value. The
SERVICE_NAMES parameter may include one or more names and different
instances may share one or more names with other instances, enabling a client to
connect to either a specific instance or to any one of a set of instances, depending
on the service name chosen in the connection string.
SPFILE
When you use an SPFILE, all Oracle RAC database instances must use the
SPFILE and the file must be on shared storage.
THREAD
Specifies the number of the redo threads to be used by an instance. You can
specify any available redo thread number if that thread number is enabled and
is not used. If specified, this parameter must have unique values on all
instances. The best practice is to use the INSTANCE_NAME parameter to specify
redo log groups.
Related Topics:
Oracle Database Reference
Administering Database Instances and Cluster Databases 3-21
Initialization Parameter Use in Oracle RAC
Parameters That Must Have Identical Settings on All Instances
Certain initialization parameters that are critical at database creation or that affect
certain database operations must have the same value for every instance in an Oracle
RAC database. Specify these parameter values in the SPFILE or in the individual
PFILEs for each instance. The following list contains the parameters that must be
identical on every instance:
COMPATIBLE
CLUSTER_DATABASE
CONTROL_FILES
DB_BLOCK_SIZE
DB_DOMAIN
DB_FILES
DB_NAME
DB_RECOVERY_FILE_DEST
DB_RECOVERY_FILE_DEST_SIZE
DB_UNIQUE_NAME
INSTANCE_TYPE (RDBMS or ASM)
PARALLEL_EXECUTION_MESSAGE_SIZE
REMOTE_LOGIN_PASSWORDFILE
UNDO_MANAGEMENT
The following parameters must be identical on every instance only if the parameter
value is set to zero:
DML_LOCKS
RESULT_CACHE_MAX_SIZE
Parameters That Have Unique Settings on All Instances
When it is necessary to set parameters that have unique settings on a policy-managed
database, you can ensure that instances always use the same name on particular nodes
by running the srvctl modify instance -n node_name -i instance_name
command for each server that can be assigned to the database's server pool. Then a
unique value of the parameter can be specified for instance_name that is used
whenever the database runs on node_name.
Specify the ORACLE_SID environment variable, which consists of the database name
and the number of the INSTANCE_NAME assigned to the instance.
Use the CLUSTER_INTERCONNECTS initialization parameter to specify an alternative
interconnect to the one Oracle Clusterware is using for the private network. Each
instance of the Oracle RAC database gets a unique value when setting the
CLUSTER_INTERCONNECTS initialization parameter.
Oracle Database uses the INSTANCE_NUMBER parameter to distinguish among
instances at startup and the INSTANCE_NAME parameter to assign redo log groups to
specific instances. The instance name can take the form
db_unique_name_instance_number and when it has this form of name and
number separated by an underscore, the number after the underscore is used as the
INSTANCE_NUMBER. With Oracle Database 11.2 using Grid Plug and Play, you no
longer have to explicitly assign instance numbers for policy-managed databases and
the instance name defaults to db_unique_name_instance_number, where Oracle
Database assigns the instance number.
3-22 Oracle Real Application Clusters Administration and Deployment Guide
Initialization Parameter Use in Oracle RAC
When you specify UNDO_TABLESPACE with automatic undo management enabled,
then set this parameter to a unique undo tablespace name for each instance.
If you use the ROLLBACK_SEGMENTS parameters, then Oracle recommends setting
unique values for it by using the SID identifier in the SPFILE. However, you must set
a unique value for INSTANCE_NUMBER for each instance and you cannot use a default
value.
Using the ASM_PREFERRED_READ_FAILURE_GROUPS initialization parameter, you
can specify a list of preferred read failure group names. The disks in those failure
groups become the preferred read disks. Thus, every node can read from its local
disks. This results in higher efficiency and performance and reduced network traffic.
The setting for this parameter is instance-specific, and the values need not be the same
on all instances.
Related Topics:
Administering Multiple Cluster Interconnects on Linux and UNIX Platforms
In Oracle RAC environments that run on Linux and UNIX platforms,
you can use the CLUSTER_INTERCONNECTS initialization parameter to
specify an alternative interconnect to the one Oracle Clusterware is using
for the private network.
Parameters That Should Have Identical Settings on All Instances
Oracle recommends that the parameters listed here have identical settings on all
instances.
Oracle recommends that you set the values for the parameters in Table 3-4 to the same
value on all instances. Although you can have different settings for these parameters
on different instances, setting each parameter to the same value on all instances
simplifies administration.
Table 3-4
Parameters That Should Have Identical Settings on All Instances
Parameter
Description
ARCHIVE_LAG_TARGET
Different values for instances in your Oracle RAC database are
likely to increase overhead because of additional automatic
synchronization performed by the database processing.
When using either Oracle Streams downstream capture or Oracle
GoldenGate integrated capture mode in a downstream capture
configuration with your Oracle RAC database, the value must be
greater than zero.
CLUSTER_DATABASE_I
NSTANCES
While it is preferable for this parameter to have identical settings
across all Oracle RAC database instances, it is not required.
LICENSE_MAX_USERS
Because this parameter determines a database-wide limit on the
number of users defined in the database, it is useful to have the
same value on all instances of your database so you can see the
current value no matter which instance you are using. Setting
different values may cause Oracle Database to generate additional
warning messages during instance startup, or cause commands
related to database user management to fail on some instances.
Administering Database Instances and Cluster Databases 3-23
Converting an Administrator-Managed Database to a Policy-Managed Database
Table 3-4
(Cont.) Parameters That Should Have Identical Settings on All Instances
Parameter
Description
LOG_ARCHIVE_FORMAT
If you do not use the same value for all your instances, then you
unnecessarily complicate media recovery. The recovering instance
expects the required archive log file names to have the format
defined by its own value of LOG_ARCHIVE_FORMAT, regardless of
which instance created the archive log files.
Databases that support Oracle Data Guard, either to send or
receive archived redo log files, must use the same value of
LOG_ARCHIVE_FORMAT for all instances.
SPFILE
If this parameter does not identify the same file to all instances,
then each instance may behave differently and unpredictably in
fail over, load-balancing, and during normal operations.
Additionally, a change you make to the SPFILE with an ALTER
SYSTEM SET or ALTER SYSTEM RESET command is saved only
in the SPFILE used by the instance where you run the command.
Your change is not reflected in instances using different SPFILEs.
If the SPFILE values are different in instances for which the values
were set by the server, then you should restart the instances that
are not using the default SPFILE.
TRACE_ENABLED
If you want diagnostic trace information to be always available for
your Oracle RAC database, you must set TRACE_ENABLED to
TRUE on all of your database instances. If you trace on only some
of your instances, then diagnostic information might not be
available when required should the only accessible instances be
those with TRACE_ENABLED set to FALSE.
UNDO_RETENTION
By setting different values for UNDO_RETENTION in each instance,
you are likely to reduce scalability and encounter unpredictable
behavior following a failover. Therefore, you should carefully
consider whether there are any benefits before you assign
different values for this parameter to the instances in your Oracle
RAC database.
Related Topics:
Oracle Streams Replication Administrator's Guide
Converting an Administrator-Managed Database to a Policy-Managed
Database
You can convert an administrator-managed database to a policy-managed database.
Note:
If the administrator-managed database is configured for a low-privileged user
and you attempt to convert the database to a policy-managed database, then
you must manually add a wallet (if one does not already exist) for this low
privileged user, so that a Windows service for Oracle Database can be created.
To convert an administrator-managed database:
3-24 Oracle Real Application Clusters Administration and Deployment Guide
Converting an Administrator-Managed Database to a Policy-Managed Database
1.
Check the current configuration of all services and the database (if you make a
mistake and need to recover, then you can know what the configuration looked
like when you began), as follows:
srvctl config database -db db_unique_name
srvctl config service -db db_unique_name
2.
Create a server pool for the policy-managed database (you must be a cluster
administrator to do this), as follows:
srvctl add srvpool -serverpool server_pool -min 0 -max n
In the preceding command, 0 is the minimum number of servers you want in the
server pool and n is the maximum.
Note:
This step does not necessarily place servers in the newly-created server pool.
If there are no servers in the Free pool from which the new server pool can
allocate servers, for example, then you may have to use the srvctl
relocate server command to relocate a server from another server pool
once the conversion is complete.
3.
Stop the database using Oracle Enterprise Manager or SRVCTL, as follows:
srvctl stop database -db db_unique_name
4.
Modify the database to be in the new server pool, as follows:
srvctl modify database -db db_unique_name -serverpool server_pool
5.
Add a service user to the wallet, as follows:
crsctl add wallet -type OSUSER -user user_name -passwd
6.
Check the status of the database to confirm that it is now policy managed by
repeating the commands in step 1.
Configure Oracle Enterprise Manager to recognize the change you made in the
previous procedure, as follows:
1.
In order for Oracle Enterprise Manager Cloud Control to recognize the new
database instances, you must change the instance name from db_unique_name#
to db_unique_name_# (notice the additional underscore (_) before the number
sign (#) character).
2.
Rename the orapwd file in the dbs/database directory (or create a new orapwd
file by running the orapwd command).
By default, there is an orapwd file with the instance name appended to it, such as
orapwdORCL1. You must change the name of the file to correspond to the
instance name you changed in the previous step. For example, you must change
orapwdORCL1 to orapwdORCL_1 or create a new orapwd file.
You cannot directly convert a policy-managed database to an administrator-managed
database. Instead, you can remove the policy-managed configuration using the
srvctl remove database and srvctl remove service commands, and then
register the same database as an administrator-managed database using the srvctl
add database and srvctl add instance commands. Once you register the
Administering Database Instances and Cluster Databases 3-25
Managing Memory Pressure for Database Servers
database and instance, you must use the srvctl add service command to add
back the services as you removed them.
Services for administrator-managed databases continue to be defined by the
PREFERRED and AVAILABLE definitions. For policy-managed databases, a service is
defined to a database server pool and can either be uniform (running on all instances in
the server pool) or singleton (running on only one instance in the server pool). If you
change the management policy of the database, then you must recreate the database
services to be either uniform/singleton or PREFERRED/AVAILABLE, depending upon
which database management policy you choose.
Related Topics:
Server Control Utility Reference
Service Deployment Options
Managing Memory Pressure for Database Servers
Enterprise database servers can use all available memory due to too many open
sessions or runaway workloads. Running out of memory can result in failed
transactions or, in extreme cases, a restart of the server and the loss of a valuable
resource for your applications. Memory Guard detects memory pressure on a server
in real time and redirects new sessions to other servers to prevent using all available
memory on the stressed server.
When Oracle Database QoS Management is enabled and managing an Oracle
Clusterware server pool, Cluster Health Monitor sends a metrics stream that provides
real-time information about memory resources for the cluster servers to Memory
Guard. This information includes the following:
•
Amount of available memory
•
Amount of memory currently in use
If Memory Guard determines that a node is experiencing memory pressure, then the
database services managed by Oracle Clusterware are stopped on that node,
preventing new connections from being created. After the memory stress is relieved,
the services on that node are restarted automatically, and the listener starts sending
new connections to that server. The memory pressure can be relieved in several ways
(for example, by closing existing sessions or by user intervention).
Rerouting new sessions to different servers protects the existing workloads on the
memory-stressed server and enables the server to remain available. Memory Guard is
a feature of Oracle RAC that manages the memory pressure for servers, adding a new
resource protection capability in managing service levels for applications hosted on
Oracle RAC databases.
Quiescing Oracle RAC Databases
The procedure for quiescing Oracle RAC databases is identical to quiescing a
noncluster database.
You use the ALTER SYSTEM QUIESCE RESTRICTED statement from one instance.
You cannot open the database from any instance while the database is in the process of
being quiesced. When all non-DBA sessions become inactive, the ALTER SYSTEM
QUIESCE RESTRICTED statement finishes, and the database is considered as in a
quiesced state. In an Oracle RAC environment, this statement affects all instances, not
just the one from which the statement is issued.
3-26 Oracle Real Application Clusters Administration and Deployment Guide
Administering Multiple Cluster Interconnects on Linux and UNIX Platforms
To successfully issue the ALTER SYSTEM QUIESCE RESTRICTED statement in an
Oracle RAC environment, you must have the Database Resource Manager feature
activated, and it must have been activated since instance startup for all instances in the
cluster database. It is through the facilities of the Database Resource Manager that
non-DBA sessions are prevented from becoming active. Also, while this statement is in
effect, any attempt to change the current resource plan is queued until after the system
is unquiesced.
These conditions apply to Oracle RAC:
•
If you issued the ALTER SYSTEM QUIESCE RESTRICTED statement but Oracle
Database has not finished processing it, you cannot open the database.
•
You cannot open the database if it is in a quiesced state.
•
The ALTER SYSTEM QUIESCE RESTRICTED and ALTER SYSTEM UNQUIESCE
statements affect all instances in an Oracle RAC environment, not just the instance
that issues the command.
Note:
You cannot use the quiesced state to take a cold backup. This is because Oracle
Database background processes may still perform updates for Oracle
Database internal purposes even while the database is in quiesced state. In
addition, the file headers of online data files continue to look like they are
being accessed. They do not look the same as if a clean shutdown were done.
You can still take online backups while the database is in a quiesced state.
Related Topics:
Oracle Database Administrator’s Guide
Oracle Database SQL Language Reference
Administering Multiple Cluster Interconnects on Linux and UNIX
Platforms
In Oracle RAC environments that run on Linux and UNIX platforms, you can use the
CLUSTER_INTERCONNECTS initialization parameter to specify an alternative
interconnect to the one Oracle Clusterware is using for the private network.
Note:
The CLUSTER_INTERCONNECTS initialization parameter should not be set to
highly available IP (HAIP) addresses provided by Redundant Interconnect
Usage. HAIP addresses are recognized automatically.
If you set multiple values for CLUSTER_INTERCONNECTS, then Oracle Database uses
all of the network interfaces that you specify for the interconnect, providing load
balancing if all of the listed interconnects remain operational. You must use identical
values, including the order in which the interconnects are listed, on all instances of
your database when defining multiple interconnects with this parameter.
Administering Database Instances and Cluster Databases 3-27
Administering Multiple Cluster Interconnects on Linux and UNIX Platforms
Note:
Oracle does not recommend setting the CLUSTER_INTERCONNECTS
initialization parameter, which overrides the default interconnect settings at
the operating system level.
Instead, the best practice is to use Redundant Interconnect Usage, available with
Oracle Grid Infrastructure 11g release 2 (11.2) for Oracle RAC and Oracle Real
Application Clusters One Node 11g release 2 (11.2) databases, and later. For databases
that precede Oracle Database 11g release 2 (11.2), use operating system-based network
bonding technologies to enable high availability (and load balancing) for network
interface cards meant to be used as the cluster interconnect. If you want to use
multiple database versions in one cluster, you can combine both techniques.
Redundant Interconnect Usage will use the interfaces as presented on the operating
system level, regardless of bonding. For more information regarding bonding
technologies contact your operating system vendor.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Use Cases for Setting the CLUSTER_INTERCONNECTS Parameter
The CLUSTER_INTERCONNECTS initialization parameter requires an IP address. It
enables you to specify multiple IP addresses, separated by colons. Oracle RAC
network traffic is distributed between the specified IP addresses.
Note:
•
Oracle does not recommend setting the CLUSTER_INTERCONNECTS
parameter when using a policy-managed database.
•
Oracle recommends that all databases and Oracle Clusterware use the
same interconnect network.
Typically, you set the CLUSTER_INTERCONNECTS parameter only in the following
situations:
•
The cluster is running multiple databases and you need the interconnect traffic to
be separated and you do not use Redundant Interconnect Usage.
•
You have a single IP address that is made highly available by the operating
system, and it does not have a stable interface name (for example, the name can
change when you restart).
Do not set the CLUSTER_INTERCONNECTS parameter for the following common
configurations:
•
If you want to use Redundant Interconnect Usage.
•
If you have only one cluster interconnect.
•
If the default cluster interconnect meets the bandwidth requirements of your
Oracle RAC database, which is typically the case.
3-28 Oracle Real Application Clusters Administration and Deployment Guide
Customizing How Oracle Clusterware Manages Oracle RAC Databases
Consider the following important points when specifying the
CLUSTER_INTERCONNECTS initialization parameter:
•
The CLUSTER_INTERCONNECTS initialization parameter is useful only in Linux
and UNIX environments where UDP IPC is enabled.
•
Specify a different value for each instance of the Oracle RAC database when
setting the CLUSTER_INTERCONNECTS initialization parameter in the parameter
file.
•
The IP addresses you specify for the different instances of the same database on
different nodes must belong to network adapters that connect to the same
interconnect network.
•
If you specify multiple IP addresses for this parameter, then list them in the same
order for all instances of the same database. For example, if the parameter for the
first instance on node1 lists the IP addresses of the alt0:, fta0:, and ics0:
devices in that order, then the parameter for the second instance on node2 must
list the IP addresses of the equivalent network adapters in the same order.
•
If an operating system error occurs while Oracle Database is writing to the
interconnect that you specify with the CLUSTER_INTERCONNECTS parameter,
then Oracle Database returns an error even if some other interfaces are available.
This is because the communication protocols between Oracle Database and the
interconnect can vary greatly depending on your platform. See your Oracle
Database platform-specific documentation for more information.
Example
Consider setting CLUSTER_INTERCONNECTS when a single cluster interconnect
cannot meet your bandwidth requirements. You may need to set this parameter in
data warehouse environments with high interconnect bandwidth demands from one
or more databases that cannot use Redundant Interconnect Usage.
For example, if you have two databases with high interconnect bandwidth
requirements, then you can override the default interconnect provided by your
operating system and nominate a different interconnect for each database using the
following syntax in each server parameter file where ipn is an IP address in standard
dot-decimal format, for example: 144.25.16.214:
Database One: crm1.CLUSTER_INTERCONNECTS = ip1
Database Two: ext1.CLUSTER_INTERCONNECTS = ip2
If you have one database with high bandwidth demands, then you can nominate
multiple interconnects using the following syntax:
CLUSTER_INTERCONNECTS = ip1:ip2:...:ipn
Related Topics:
Oracle Database Reference
Customizing How Oracle Clusterware Manages Oracle RAC Databases
Use these examples to minimize Oracle Clusterware control over Oracle RAC
databases, which you may need to do during upgrades.
By default, Oracle Clusterware controls database restarts in Oracle RAC
environments. In some cases, you may need to minimize the level of control that
Administering Database Instances and Cluster Databases 3-29
Customizing How Oracle Clusterware Manages Oracle RAC Databases
Oracle Clusterware has over your Oracle RAC database, for example, during database
upgrades.
Note:
When using third-party clusterware, Oracle recommends that you use Oracle
Clusterware to manage the Oracle RAC instances. If you set the instance to
manual and start it with third-party clusterware, then do not use the thirdparty clusterware to monitor and restart database instances because Oracle
Clusterware must do that.
To prevent Oracle Clusterware from restarting your Oracle RAC database when you
restart your system, or to avoid restarting failed instances more than once, configure a
management policy to define the degree of control. There are two management
policies: AUTOMATIC, which is the default, and MANUAL. If the management
policy is set to AUTOMATIC, the database is automatically restored to its previous
running condition (started or stopped) upon restart of the database host computer. If
MANUAL, the database is never automatically restarted upon restart of the database
host computer. A MANUAL setting does not prevent Oracle Restart from monitoring
the database while it is running and restarting it if a failure occurs.
Use SRVCTL commands to display and change the Oracle Clusterware management
policies, as shown in the following examples:
Example 1: Display the Current Management Policy
Use the following command syntax to display the current management policy where
db_unique_name is the name of the database for which you want to change
management policies:
srvctl config database -db db_unique_name -all
Example 2: Change the Current Management Policy to Another Management
Policy
Use the following SRVCTL command syntax to change the current management
policy to either AUTOMATIC, MANUAL, or NORESTART:
srvctl modify database -db db_unique_name -policy [AUTOMATIC | MANUAL | NORESTART]
This command syntax sets the resource attribute of the database resource.
Example 3: Specify a Management Policy for a New Database
When you add a new database using the srvctl add database command, you can
use the -policy parameter to specify the management policy as either AUTOMATIC,
MANUAL, or NORESTART, as shown in the following example where db_unique_name
is the name of the database:
srvctl add database -db db_unique_name -policy [AUTOMATIC | MANUAL | NORESTART]
-oraclehome $ORACLE_HOME -dbname DATA
This command syntax places the new database under the control of Oracle
Clusterware. If you do not provide a management policy option, then Oracle Database
uses the default value of automatic. After you change the management policy, the
Oracle Clusterware resource records the new value for the affected database.
3-30 Oracle Real Application Clusters Administration and Deployment Guide
Advanced Oracle Enterprise Manager Administration
Related Topics:
srvctl config database
Displays the configuration for an Oracle RAC database or lists all
configured databases that are registered with Oracle Clusterware.
srvctl modify database
Modifies the configuration for a database.
srvctl add database
Adds a database configuration to Oracle Clusterware.
Advanced Oracle Enterprise Manager Administration
You can install, configure, and monitor an Oracle RAC database from a single location
using Oracle Enterprise Manager Cloud Control.
This section provides advanced administration tasks that are not covered inOracle
Database 2 Day + Real Application Clusters Guide or in "Overview of Monitoring and
Tuning Oracle RAC Databases".
This section includes the following topics:
•
Using Oracle Enterprise Manager Cloud Control to Discover Nodes and Instances
•
Other Oracle Enterprise Manager Capabilities
•
Administering Jobs and Alerts in Oracle RAC
Using Oracle Enterprise Manager Cloud Control to Discover Nodes and Instances
Discovering Oracle RAC database and instance targets in Oracle Enterprise Manager
enables monitoring and administration.
Oracle Enterprise Manager Cloud Control enables you to use the Oracle Enterprise
Manager console interface to discover Oracle RAC database and instance targets.
If the Oracle Enterprise Manager Cloud Control agents are installed on a cluster that
has an Oracle RAC database, then Oracle RAC database targets are discovered at
install time. You can use the console interface to discover targets if a database is
created after agents are installed or if a database is not automatically discovered at
agent install time.
To discover nodes and instances, use Oracle Enterprise Manager Cloud Control as
follows:
1.
Log in to Oracle Enterprise Manager and click the Targets tab.
2.
Click the Database tab to view all of the available targets. The column labeled
Types shows the Oracle RAC databases using the entry Cluster Database.
3.
Add the database target by selecting the target name, then clicking Add. The Add
Database Target: Specify Host page appears, which enables you to add databases,
listeners, and Oracle ASM as monitored targets.
4.
Click the flashlight icon to display the available host names, select a host, then
click Continue. The Add Database: Specify Source page appears.
5.
Either request Oracle Enterprise Manager to discover only noncluster databases
and listeners, or to discover all cluster databases, noncluster databases, and
listeners on the cluster, then click Continue.
Administering Database Instances and Cluster Databases 3-31
Advanced Oracle Enterprise Manager Administration
6.
If this procedure did not discover your reconfigured cluster database and all of its
instances, you can use the Targets Discovered on Cluster page to manually
configure your cluster database and noncluster databases.
Other Oracle Enterprise Manager Capabilities
This section lists Oracle Enterprise Manager capabilities available with Oracle
Enterprise Manager 12c.
•
The Oracle Grid Infrastructure/Oracle RAC Provisioning deployment procedure
provisions Oracle RAC 12c and Oracle Grid Infrastructure. This procedure also
has a feature called Profiles, which enables you to record the inputs and
subsequently use them for repeated deployments.
•
Dynamic prerequisites for the new procedures enable Oracle Enterprise Manager,
when connected to My Oracle Support (formerly OracleMetaLink), to download
the latest prerequisites and tools for Oracle RAC provisioning.
•
The existing One-Click Extend Cluster Database capability now supports Oracle
RAC 12c stack.
•
The existing Delete/Scale down Oracle Real Application Clusters capability is certified
with Oracle RAC 12c clusters.
•
The existing Oracle Database Provisioning procedure now supports provisioning of
single instances of Oracle Database 12c.
•
A new deployment procedure—Oracle Grid Infrastructure Provisioning for
Standalone Servers—has been introduced to provision Oracle Grid Infrastructure
12c for noncluster databases.
Administering Jobs and Alerts in Oracle RAC
The Cluster Database Home page shows all of the instances in the Oracle RAC
database and provides an aggregate collection of several Oracle RAC-specific statistics
that are collected by the Automatic Workload Repository (AWR) for server
manageability.
You do not need to navigate to an instance-specific page to see these details. However,
on the Cluster Database Home page, if an instance is down that should be operating,
or if an instance has a high number of alerts, then you can drill down to the instancespecific page for each alert.
To perform specific administrative tasks as described in the remainder of this section,
log in to the target Oracle RAC database, navigate to the Cluster Database Home page,
and click the Administration tab.
This section includes the following topics:
•
Administering Jobs in Oracle RAC
•
Administering Alerts in Oracle RAC with Oracle Enterprise Manager
•
Using Defined Blackouts in Oracle Enterprise Manager
Administering Jobs in Oracle RAC
You can administer Oracle Enterprise Manager jobs at both the database and instance
levels. For example, you can create a job at the cluster database level to run on any
3-32 Oracle Real Application Clusters Administration and Deployment Guide
Advanced Oracle Enterprise Manager Administration
active instance of the target Oracle RAC database. Or you can create a job at the
instance level to run on the specific instance for which you created it. If there is a
failure, then recurring jobs can run on a surviving instance.
Because you can create jobs at the instance level, cluster level, or cluster database level,
jobs can run on any available host in the cluster database. This applies to scheduled
jobs as well. Oracle Enterprise Manager also displays job activity in several categories,
including, Active, History, and Library.
Use the Jobs tab to submit operating system scripts and SQL scripts and to examine
scheduled jobs. For example, to create a backup job for a specific Oracle RAC database:
1.
Click Targets and click the database for which you want to create the job.
2.
Log in to the target database.
3.
When Oracle Enterprise Manager displays the Database Home page, click
Maintenance.
4.
Complete the Enterprise Manage Job Wizard pages to create the job.
Administering Alerts in Oracle RAC with Oracle Enterprise Manager
You can use Oracle Enterprise Manager to configure Oracle RAC environment alerts.
You can also configure special Oracle RAC database tests, such as global cache
converts, consistent read requests, and so on.
Oracle Enterprise Manager distinguishes between database- and instance-level alerts
in Oracle RAC environments. Alert thresholds for instance-level alerts, such as archive
log alerts, can be set at the instance target level. This function enables you to receive
alerts for the specific instance if performance exceeds your threshold. You can also
configure alerts at the database level, such as setting alerts for tablespaces, to avoid
receiving duplicate alerts at each instance.
Related Topics:
Oracle Database PL/SQL Packages and Types Reference
See Also:
Oracle Technology Network for an example of configuring alerts in Oracle
RAC, and Oracle Database PL/SQL Packages and Types Reference for information
about using packages to configure thresholds
Using Defined Blackouts in Oracle Enterprise Manager
You can define blackouts (which are time periods in which database monitoring is
suspended so that maintenance operations do not skew monitoring data or generate
needless alerts) for all managed targets of an Oracle RAC database to prevent alerts
from occurring while performing maintenance. You can define blackouts for an entire
cluster database or for specific cluster database instances.
Administering Database Instances and Cluster Databases 3-33
Advanced Oracle Enterprise Manager Administration
3-34 Administration and Deployment Guide
4
Administering Oracle RAC One Node
Oracle Real Application Clusters One Node (Oracle RAC One Node) is a single
instance of an Oracle Real Application Clusters (Oracle RAC) database that runs on
one node in a cluster. This option adds to the flexibility that Oracle offers for database
consolidation. You can consolidate many databases into one cluster with minimal
overhead while also providing the high availability benefits of failover protection,
online rolling patch application, and rolling upgrades for the operating system and
Oracle Clusterware.
This chapter includes the following topics:
•
Creating an Oracle RAC One Node Database
•
Converting Databases
•
Online Database Relocation
Creating an Oracle RAC One Node Database
You can create Oracle RAC One Node databases by using Rapid Home Provisioning
or the Database Configuration Assistant (DBCA), as with any other Oracle database
(manually created scripts are also a valid alternative).
You can create an Oracle RAC One Node database using Rapid Home Provisioning
and the rhpctl add database command with the -dbtype RACONENODE
paramater. You can also include an Oracle RAC One Node database using the rhpctl
add workingcopy command.
Oracle RAC One Node databases may also be the result of a conversion from either a
single-instance Oracle database (using rconfig, for example) or an Oracle RAC
database. Typically, Oracle-provided tools register the Oracle RAC One Node
database with Oracle Clusterware. Depending on your configuration, automatic
registration of an Oracle RAC One Node database with Oracle Clusterware may not
have happened. If this is the case, then follow the steps in this section to register the
Oracle RAC One Node database with Oracle Clusterware.
Note:
Oracle recommends that you manage Oracle RAC One Node databases with
Server Control Utility (SRVCTL). You can only perform certain operations
(such as Online Database Relocation) using SRVCTL.
If your Oracle RAC One Node database did not register automatically with Oracle
Clusterware, then use the srvctl add database command to add an Oracle RAC
One Node database to your cluster. For example:
Administering Oracle RAC One Node 4-1
Converting Databases
$ srvctl add database -dbtype RACONENODE [-server server_list]
[-instance instance_name] [-timeout timeout]
Use the -server option and the -instance option when adding an administratormanaged Oracle RAC One Node database.
For Oracle RAC One Node databases, you must configure at least one dynamic
database service (in addition to and opposed to the default database service). When
using an administrator-managed Oracle RAC One Node database, service registration
is performed as with any other Oracle RAC database. When you add services to a
policy-managed Oracle RAC One Node database, SRVCTL does not accept any
placement information, but instead configures those services using the value of the
SERVER_POOLS attribute.
Note:
When adding an administrator-managed Oracle RAC One Node database,
you can optionally supply an instance prefix with the -instance
instance_name option of the srvctl add database command. The
name of the instance will then be prefix_1. If you do not specify an instance
prefix, then the first 12 characters of the unique name of the database becomes
the prefix. The instance name changes to prefix_2 during an online database
relocation and reverts back to prefix_1 during a subsequent online database
relocation. The same instance name is used on failover.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
srvctl add database
Adds a database configuration to Oracle Clusterware.
Using DBCA in Interactive Mode to Add Database Instances to Target Nodes
Converting Databases
Using SRVCTL, you can convert an Oracle RAC database with one instance to an
Oracle RAC One Node database and vice versa.
This section includes the following topics:
•
Converting a Database from Oracle RAC to Oracle RAC One Node
•
Converting a Database from Oracle RAC One Node to Oracle RAC
Converting a Database from Oracle RAC to Oracle RAC One Node
Use SRVCTL to convert an Oracle RAC database to an Oracle RAC One Node
database.
Before converting an Oracle RAC database to an Oracle RAC One Node database, you
must first ensure that the Oracle RAC database has only one instance. If your Oracle
RAC database is administrator managed and has more than one instance, then you
must remove all instances except one using the srvctl remove instance
command. If your Oracle RAC database is policy managed and has more than one
instance, then you must stop all instances except one using the srvctl stop
instance command.
4-2 Oracle Real Application Clusters Administration and Deployment Guide
Converting Databases
If the Oracle RAC database is administrator managed, then you must change the
configuration of all services to set the preferred instance to the instance that you want
to keep as an Oracle RAC One Node database after conversion. If any service had a
PRECONNECT TAF policy, then its TAF policy must be updated to BASIC or NONE
before starting the conversion process. These services must no longer have any
available instance.
If the Oracle RAC database is policy managed, then you must change the
configuration of all services so that they all use the same server pool before you
convert the Oracle RAC database to an Oracle RAC One Node database.
You can convert an Oracle RAC database with one instance to an Oracle RAC One
Node database using the srvctl convert database command, as follows:
$ srvctl convert database -db db_unique_name -dbtype RACONENODE
[-instance instance_name -timeout timeout]
-w timeout]
Note:
An Oracle RAC database that you want to convert to Oracle RAC One Node
must either use Oracle Managed Files (to enable automatic thread allocation)
or have at least two redo threads.
Related Topics:
srvctl remove instance
srvctl stop instance
srvctl convert database
Converting a Database from Oracle RAC One Node to Oracle RAC
You can convert an Oracle RAC One Node database to an Oracle RAC database by
logging in as the Oracle RAC One Node database owner and entering the following
SRVCTL command:
srvctl convert database -db db_unique_name -dbtype RAC
If you are relocating the database you want to convert to Oracle RAC using online
database relocation, or an online database relocation has failed, then you must either
quit or complete the relocation before you run the srvctl convert database
command.
After you run this command, you must create server pools for each database service,
in addition to the database server pool. The values for SERVER_NAMES for the server
pools used by the database services must be set to the node that you converted from
an Oracle RAC One Node to an Oracle RAC node. You can use the CRSCTL utility or
Oracle Enterprise Manager to create and configure the server pools.
Converting an administrator-managed Oracle RAC One Node database to an Oracle
RAC database configures all database services so that the single-instance database is
the preferred instance for that service. After you convert the database, you can add
instances to your database by using the srvctl add instance command.
Converting a policy-managed Oracle RAC One Node database to an Oracle RAC
database sets all database services to UNIFORM cardinality. It also results in reusing
the server pool in which the database currently runs. The conversion reconfigures the
Administering Oracle RAC One Node 4-3
Online Database Relocation
database to run on all nodes in the server pool. The command does not start any
additional instances but running the srvctl start database command starts the
database on all nodes in the server pool.
Related Topics:
srvctl convert database
Online Database Relocation
You can relocate an Oracle RAC One Node database to another node while still
maintaining service availability using the online database relocation feature.
Only during a planned online database relocation is a second instance of an Oracle
RAC One Node database created, so that any database sessions can continue while the
database is relocated to a new node. You can only use online database relocation with
Oracle RAC One Node databases but you cannot use online database relocation with
Oracle RAC databases regardless of their management style (either administrator or
policy managed).
You can use the srvctl relocate database command configure the amount of
time after the relocated database starts and services are migrated, before the former
instance of the database stops. This configured amount of time is not an upper bound
on the amount of time taken by the entire operation, but only controls how long the
relocated database waits for connections to migrate from the former instance to the
new instance, before stopping the former instance.
Online database relocation occurs, as follows:
1.
Start a new database instance in a different location.
2.
Move all the services to the relocated instance.
3.
Wait for all the connections to migrate to the relocated instance.
4.
Shut down the former database instance, forcing any remaining connections to
move to the relocated instance.
The online relocation timeout is the amount of time you configure to complete step 3.
If your Oracle RAC One Node database is administrator managed, then the target
node to which you want to relocate the database instance must be part of the Free
server pool at the moment you initiate the relocation. If you have a spare target node
in the Free server pool, then this node is added to the candidate list for the Oracle RAC
One Node database.
4-4 Oracle Real Application Clusters Administration and Deployment Guide
Online Database Relocation
Note:
•
When you relocate a database instance to a target node that is not
currently in the candidate server list for the database, you must copy the
password file, if configured, to the target node, unless you use shared
password files stored in Oracle ASM.
When you use password file-based authentication for remote
management of Oracle RAC One Node databases without any shared
password file, you must have two password files on each node where the
database can run: one named SID_prefix_1 and the other named
SID_prefix_2. You must recopy both of these files to all candidate
nodes every time you update the password file. This is true for both
policy-managed and administrator-managed databases.
Oracle recommends using Oracle Clusterware to start and stop the
database, and defining users in the data dictionary for other management.
•
Before you relocate a database instance, you must ensure that the
database service user is added to the wallet. Run crsctl query
wallet -type OSUSER -all to check whether the database service
user is in the wallet. If not, then run crsctl add wallet -type
OSUSER -user user_name -passwd to add the database service user
to the wallet.
Use the srvctl relocate database command to initiate relocation of an Oracle
RAC One Node database. For example:
$ srvctl relocate database -d rac1 -n node7
Related Topics:
Oracle Database Administrator’s Guide
srvctl relocate database
Administering Oracle RAC One Node 4-5
Online Database Relocation
4-6 Administration and Deployment Guide
5
Workload Management with Dynamic
Database Services
Workload management includes load balancing, enabling clients for Oracle Real
Application Clusters (Oracle RAC), distributed transaction processing, and services.
This chapter includes the following topics:
•
Connection Load Balancing
•
Load Balancing Advisory
•
Enabling Clients for Oracle RAC
•
Distributed Transaction Processing in Oracle RAC
•
Automatic Workload Repository
•
Measuring Performance by Service Using the Automatic Workload Repository
•
Automatic Workload Repository Service Thresholds and Alerts
•
Using Oracle Services
•
Service Deployment Options
•
Administering Services
•
Global Services
•
Connecting to a Service: An Example
Connection Load Balancing
Oracle Net Services provides the ability to distribute client connections across the
instances in an Oracle RAC configuration.
There are two types of load balancing that you can implement: client-side and serverside load balancing. Client-side load balancing distributes the connection requests
across the listeners, independently at each client. With server-side load balancing, the
SCAN listener directs a connection request to the best instance currently providing the
service, based on the -clbgoal and -rlbgoal settings for the service.
The SCAN listener is aware of the HTTP protocol so that it can redirect HTTP clients
to the appropriate handler, which can reside on different nodes in the cluster than the
node on which the SCAN listener resides.
In an Oracle RAC database, client connections should use both types of connection
load balancing.
•
Server-Side Load Balancing
Workload Management with Dynamic Database Services 5-1
Connection Load Balancing
•
Generic Database Clients
•
Client-Side Load Balancing
•
Client-Side Connection Configuration for Older Clients
Related Topics:
Oracle Database Net Services Administrator's Guide
Server-Side Load Balancing
When you create an Oracle RAC database with DBCA, it automatically:
•
Configures and enables server-side load balancing
•
Creates a sample client-side load balancing connection definition in the
tnsnames.ora file on the server
The Oracle Clusterware Database Agent is responsible for managing the
LISTENER_NETWORKS parameter.
Note:
Note: If you set the REMOTE_LISTENER parameter manually, then set this
parameter to scan_name:scan_port.
FAN, Fast Connection Failover, and the load balancing advisory depend on an
accurate connection load balancing configuration that includes setting the connection
load balancing goal for the service. You can use a goal of either LONG or SHORT for
connection load balancing. These goals have the following characteristics:
•
SHORT: Use the SHORT connection load balancing method for applications that
use run-time load balancing. When using connection pools that are integrated
with Load Balancing Advisory, set the CLB_GOAL to SHORT. The following
example modifies the service known as oltpapp, using SRVCTL to set the
connection load balancing goal to SHORT:
$ srvctl modify service -db db_unique_name -service oltpapp -clbgoal SHORT
•
LONG: Use the LONG connection load balancing method if run-time load
balancing is not required. This is typical for batch operations. LONG is the default
connection load balancing goal. The following is an example of modifying a
service, batchconn, using SRVCTL to define the connection load balancing goal
for long-lived sessions:
$ srvctl modify service -db db_unique_name -service batchconn -clbgoal LONG
Generic Database Clients
Oracle Net Services enables you to add the CONNECT_TIMEOUT, RETRY_COUNT, and
TRANSPORT_CONNECT_TIMEOUT parameters to the tnsnames.ora connection
string.
For example, when using SCAN addresses for the remote listeners at the database:
jdbc:oracle:thin:@(DESCRIPTION =
(TRANSPORT_CONNECT_TIMEOUT=3)(CONNECT_TIMEOUT=60)
5-2 Oracle Real Application Clusters Administration and Deployment Guide
Connection Load Balancing
(RETRY_COUNT=3)(FAILOVER=ON)
(ADDRESS_LIST =(ADDRESS=(PROTOCOL=tcp)
(HOST=CLOUD-SCANVIP.example.com)(PORT=5221))
(CONNECT_DATA=(SERVICE_NAME=orcl)))
Remote_listeners=CLOUD-SCANVIP.example.com:5221
For example, when using remote listeners pointing to VIPs at the database:
jdbc:oracle:thin:@(DESCRIPTION =
(TRANSPORT_CONNECT_TIMEOUT=3)
(CONNECT_TIMEOUT=60)(RETRY_COUNT=20)
(RETRY_DELAY=3)(FAILOVER=ON)
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=CLOUD-VIP1)(PORT=1521) )
(ADDRESS=(PROTOCOL=tcp)(HOST=CLOUD-VIP2)(PORT=1521) )
(ADDRESS=(PROTOCOL=tcp)(HOST=CLOUD-VIP3)(PORT=1521) ))
(CONNECT_DATA=(SERVICE_NAME=GOLD)))
The value of these parameters is expressed in seconds. In the preceding examples,
Oracle Net waits for 60 seconds for each full connection to receive a response, after
which it assumes that a failure occurred and retries the next address in the
ADDRESS_LIST. Oracle Net retries the address list 3 times before it returns a failure
message to the client. The TRANSPORT_CONNECT_TIMEOUT parameter establishes the
time to wait to establish a TCP connection to the database server.
For SCAN, Oracle Net Services tries all three addresses (returned by the SCAN
address) before returning a failure to the client. EZConnect with SCAN includes this
connection failover feature.
This behavior is called Oracle Net connection failover. If an error is returned from a
chosen address in the list, then Oracle Net Services tries the next address in the list
until it is either successful or it has exhausted all addresses in its list.
Client-Side Connection Configuration for Older Clients
In addition to client-side load balancing, Oracle Net Services include connection
failover. If an error is returned from the chosen address in the list, Oracle Net Services
tries the next address in the list until it is either successful or it has exhausted all
addresses in its list. For SCAN, Oracle Net Services tries all three addresses before
returning a failure to the client. EZConnect with SCAN includes this connection
failover feature.
To increase availability, you can specify a timeout that specifies how long Oracle Net
waits for a response from the listener before returning an error. The method of setting
this timeout parameter depends on the type of client access. Oracle Net maintains
these parameters for backward compatibility.
This section includes the following topics:
•
JDBC-Thin Clients
•
OCI Clients
JDBC-Thin Clients
You can avoid delays by setting the
oracle.net.ns.SQLnetDef.TCP_CONNTIMEOUT_STR property, as follows:
Properties prop = new Properties ();
prop.put (oracle.net.ns.SQLnetDef.TCP_CONNTIMEOUT_STR,
Workload Management with Dynamic Database Services 5-3
Connection Load Balancing
"" + (1 * 1000)); // 1 second
dbPools[ poolIndex ].setConnectionProperties ( prop );
The parameter value is specified in milliseconds. Therefore, it is possible to reduce the
timeout to 500Ms if the application retries connecting.
OCI Clients
For OCI clients, create a local sqlnet.ora file on the client side.
Configure the connection timeout in this file by adding the following line:
sqlnet.outbound_connect_timeout = number_of_seconds
The granularity of the timeout value for the OCI client is in seconds. The sqlnet.ora
file affects all connections using this client.
Note:
Do not configure the connection timeout in the sqlnet.ora file on the server.
Related Topics:
Oracle Call Interface Programmer's Guide
Client-Side Load Balancing
Client-side load balancing is defined in your client connection definition
(tnsnames.ora file, for example) by setting the parameter LOAD_BALANCE=ON.
When you set this parameter to ON, Oracle Database randomly selects an address in
the address list, and connects to that node's listener. This balances client connections
across the available SCAN listeners in the cluster.
If you configured SCAN for connection requests, then client-side load balancing is not
relevant for those clients that support SCAN access. When clients connect using
SCAN, Oracle Net automatically balances the load of client connection requests across
the three IP addresses you defined for the SCAN, unless you are using EZConnect.
The SCAN listener redirects the connection request to the local listener of the instance
that is least loaded (if -clbgoal is set to SHORT) and provides the requested service.
When the listener receives the connection request, the listener connects the user to an
instance that the listener knows provides the requested service. To see what services a
listener supports, run the lsnrctl services command.
When clients connect using SCAN, Oracle Net automatically load balances client
connection requests across the three IP addresses you defined for the SCAN, unless
you are using EZConnect.
If you are using clients that do not support SCAN (for example, the client version is
pre-Oracle Database 11g release 2 (11.2)), then, to use SCAN you must change the
client tnsnames.ora to include the SCAN VIPs, and set LOAD_BALANCE=ON to
balance requests across the VIPs. For example:
Sales.example.com=(DESCRIPTION=
(ADDRESS_LIST=(LOAD_BALANCE=ON)(FAILOVER=ON)
(ADDRESS=(PROTOCOL=TCP)(HOST=172.22.67.192)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=172.22.67.193)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=172.22.67.194)(PORT=1521))
5-4 Oracle Real Application Clusters Administration and Deployment Guide
Load Balancing Advisory
(CONNECT_DATA=(SERVICE_NAME=salesservice.example.com))
))
Note:
If your database is not Oracle Database 11g release 2 (11.2), or later, and you
want to use SCAN, then you must add SCAN VIPs to the REMOTE_LISTENER
parameter to enable correct listener cross-registration.
Related Topics:
Oracle Database Reference
Load Balancing Advisory
This section describes the load balancing advisory under the following topics:
•
Overview of the Load Balancing Advisory
•
Configuring Your Environment to Use the Load Balancing Advisory
•
Load Balancing Advisory FAN Events
•
Monitoring Load Balancing Advisory FAN Events
Overview of the Load Balancing Advisory
Load balancing distributes work across all of the available Oracle RAC database
instances. Oracle recommends that applications use connection pools with persistent
connections that span the instances that offer a particular service. When using
persistent connections, connections are created infrequently and exist for a long
duration. Work comes into the system with high frequency, borrows these
connections, and exists for a relatively short duration. The load balancing advisory
provides advice about how to direct incoming work to the instances that provide the
optimal quality of service for that work. This minimizes the need to relocate the work
later.
By using the Load Balancing Advisory and run-time connection load balancing goals,
feedback is built in to the system. Work is routed to provide the best service times
globally, and routing responds gracefully to changing system conditions. In a steady
state, the system approaches equilibrium with improved throughput across all of the
Oracle RAC instances.
Standard architectures that can use the load balancing advisory include connection
load balancing, transaction processing monitors, application servers, connection
concentrators, hardware and software load balancers, job schedulers, batch schedulers,
and message queuing systems. All of these applications can allocate work.
The load balancing advisory is deployed with key Oracle clients, such as a listener, the
JDBC universal connection pool, OCI session pool, Oracle WebLogic Server Active
GridLink for Oracle RAC, and the ODP.NET Connection Pools. Third-party
applications can also subscribe to load balancing advisory events by using JDBC and
Oracle RAC FAN API or by using callbacks with OCI.
Workload Management with Dynamic Database Services 5-5
Load Balancing Advisory
Configuring Your Environment to Use the Load Balancing Advisory
You can configure your environment to use the load balancing advisory by defining
service-level goals for each service for which you want to enable load balancing.
Configuring a service-level goal enables the load balancing advisory and the
publishing of FAN load balancing events for that service. There are two types of
service-level goals for run-time connection load balancing:
•
SERVICE_TIME: Attempts to direct work requests to instances according to
response time. Load balancing advisory data is based on elapsed time for work
done in the service plus available bandwidth to the service. An example for the
use of SERVICE_TIME is for workloads such as internet shopping where the rate
of demand changes. The following example shows how to set the goal to
SERVICE_TIME for connections using the online service:
$ srvctl modify service -db db_unique_name -service online
-rlbgoal SERVICE_TIME -clbgoal SHORT
•
THROUGHPUT: Attempts to direct work requests according to throughput. The
load balancing advisory is based on the rate that work is completed in the service
plus available bandwidth to the service. An example for the use of THROUGHPUT
is for workloads such as batch processes, where the next job starts when the last
job completes. The following example shows how to set the goal to THROUGHPUT
for connections using the sjob service:
$ srvctl modify service -db db_unique_name -service sjob
-rlbgoal THROUGHPUT -clbgoal LONG
Setting the run-time connection load balancing goal to NONE disables load balancing
for the service. You can see the goal settings for a service in the data dictionary by
querying the DBA_SERVICES, V$SERVICES, and V$ACTIVE_SERVICES views. You
can also review the load balancing settings for a service using Oracle Enterprise
Manager.
Related Topics:
Administering Services
Oracle Database 2 Day + Real Application Clusters Guide
Load Balancing Advisory FAN Events
The load balancing advisory FAN events provide metrics for load balancing
algorithms.
The easiest way to take advantage of these events is to use the run-time connection
load balancing feature of an Oracle integrated client such as JDBC, Universal
Connection Pool (or the deprecated Implicit Connection Cache), ODP.NET Connection
Pools, OCI session pools, or Oracle WebLogic Server Active GridLink for Oracle RAC.
Other client applications can take advantage of FAN programatically by using the
Oracle RAC FAN API to subscribe to FAN events and execute event-handling actions
upon receipt. Table 5-1 describes the load balancing advisory FAN event parameters.
5-6 Oracle Real Application Clusters Administration and Deployment Guide
Load Balancing Advisory
See Also:
Oracle Database JDBC Developer’s Guide for more information about the Oracle
RAC FAN API
Table 5-1
Parameter
VERSION
EVENT_TYPE
SERVICE
DATABASE
INSTANCE
PERCENT
FLAG
TIMESTAMP
Load Balancing Advisory FAN Events
Description
Version of the event record. Used to identify release changes.
A load balancing advisory event is always of the SERVICEMETRICS event type.
The service name; matches the value of NAME in DBA_SERVICES.
The unique database supporting the service; matches the initialization parameter value
for DB_UNIQUE_NAME, which defaults to the value of the initialization parameter
DB_NAME.
The name of the instance that supports the service; matches the ORACLE_SID value.
The percentage of work requests to send to this database instance.
Indication of the service quality relative to the service goal. Valid values are GOOD,
VIOLATING, NO DATA, and BLOCKED.
The local time zone to use when ordering notification events.
Note:
The INSTANCE, PERCENT, and FLAG event parameters are generated for each
instance offering the service. Each set of instance data is enclosed within
braces ({}).
Related Topics:
Oracle Database JDBC Developer’s Guide
Monitoring Load Balancing Advisory FAN Events
You can use the following query against the internal queue table for load balancing
advisory FAN events to monitor load balancing advisory events generated for an
instance:
SET PAGES 60 COLSEP '|' LINES 132 NUM 8 VERIFY OFF FEEDBACK OFF
COLUMN user_data HEADING "AQ Service Metrics" FORMAT A60 WRAP
BREAK ON service_name SKIP 1
SELECT
Workload Management with Dynamic Database Services 5-7
Enabling Clients for Oracle RAC
TO_CHAR(enq_time, 'HH:MI:SS') Enq_time, user_data
FROM sys.sys$service_metrics_tab
ORDER BY 1 ;
The results of this query contain rows similar to the following:
02:56:05|SYS$RLBTYP('hr', 'VERSION=1.0 database=sales service=hr
{ {instance=sales_4 percent=38 flag=GOOD aff=TRUE}{instance=sales_1
percent=62 flag=GOOD aff=TRUE} } timestamp=2012-07-16 07:56:05')
Following is an example of a load balancing advisory event for the lba_serv service
offered on two instances (orcl1 and orcl2), as captured from Oracle Notification
Service using the Oracle RAC FAN API:
Notification Type: database/event/servicemetrics/lba_serv.example.com
VERSION=1.0 database=orcl service=lba_serv.example.com { {instance=orcl2
percent=50 flag=UNKNOWN aff=FALSE}{instance=orcl1 percent=50 flag=UNKNOWN
aff=FALSE} } timestamp=2012-07-06 13:19:12
Note:
The SERVICMETRICS events are not visible through the FAN callout
mechanism.
Enabling Clients for Oracle RAC
Oracle has integrated FAN with many of the common client application environments
that are used to connect to Oracle RAC databases. Therefore, the easiest way to use
FAN is to use an integrated Oracle Client.
The following sections discuss how FAN is integrated with Oracle Clients and how to
enable FAN events for the several specific client development environments:
•
Overview of Oracle Integrated Clients and FAN
•
Enabling JDBC-Thin Clients for Fast Connection Failover
•
Enabling JDBC Clients for Run-time Connection Load Balancing
•
Configuring JDBC-Thin Clients for Application Continuity for Java
•
Configuring JDBC-Thin Clients for Transaction Guard
•
Enabling OCI Clients for Fast Connection Failover
•
Enabling OCI Clients for Run-time Connection Load Balancing
•
Configuring OCI Clients to use Transaction Guard
•
Enabling ODP.NET Clients to Receive FAN High Availability Events
•
Enabling ODP.NET Clients to Receive FAN Load Balancing Advisory Events
•
Configuring ODP.NET Clients to use Transaction Guard
Overview of Oracle Integrated Clients and FAN
The overall goals of FAN are to enable end-to-end, lights-out recovery of applications
and load balancing based on real transaction performance.
5-8 Oracle Real Application Clusters Administration and Deployment Guide
Enabling Clients for Oracle RAC
Applications use the FAN high availability (HA) events to achieve very fast detection
of failures, balancing of connection pools following failures, and distribution of
connections again when the failed components are repaired.
The FAN events carrying load balancing advice help connection pools consistently
deliver connections to available instances that provide the best service. FAN HA is
integrated with the JDBC-thin and OCI drivers. FAN HA and FAN load balancing are
both integrated with the JDBC Universal Connection Pool (and the deprecated Implicit
Connection Cache), the OCI session pools, the ODP.NET connection pool, and Oracle
WebLogic Server Active GridLink for Oracle RAC.
Due to the integration with FAN, Oracle integrated clients are more aware of the
current status of an Oracle RAC cluster. This prevents client connections from waiting
or trying to connect to instances or services that are no longer available. When
instances start, Oracle RAC uses FAN to notify the connection pool so that the
connection pool can create connections to the recently started instance and take
advantage of the additional resources that this instance provides.
Oracle client drivers that are integrated with FAN can:
•
Remove terminated connections immediately when a service is declared DOWN at
an instance, and immediately when nodes are declared DOWN
•
Report errors to clients immediately when Oracle Database detects the NOT
RESTARTING state, instead of making the client wait while the service repeatedly
attempts to restart
Oracle connection pools that are integrated with FAN can:
•
Balance connections across all of the Oracle RAC instances when a service starts;
this is preferable to directing the sessions that are defined for the connection pool
to the first Oracle RAC instance that supports the service
•
Balance work requests at run time using load balancing advisory events
The use of client drivers or connection pools and FAN requires that you properly
configure the Oracle Notification Service to deliver the FAN events to the clients. In
addition, for load balancing, configure database connection load balancing across all
of the instances that provide the services used by the connection pool. Oracle
recommends that you configure both client-side and server-side load balancing with
Oracle Net Services. If you use DBCA to create your database, then both client-side
and server-side load balancing are configured by default.
Related Topics:
Connection Load Balancing
Oracle Net Services provides the ability to distribute client connections
across the instances in an Oracle RAC configuration.
Enabling JDBC-Thin Clients for Fast Connection Failover
Enabling Fast Connection Failover (FCF) for Universal Connection Pool and Oracle
WebLogic Server Active GridLink for Oracle RAC enables the use of FAN HA and
load balancing advisory events.
For Universal Connection Pool to use FAN, your application can use the JDBC
development environment for either JDBC OCI or JDBC Thin clients. The Java
Database Connectivity Oracle Call Interface (JDBC/OCI) driver connection pooling
Workload Management with Dynamic Database Services 5-9
Enabling Clients for Oracle RAC
functionality is part of the JDBC-thin client. This functionality is provided by the
OracleOCIConnectionPool class.
To enable FCF for the JDBC-thin client, call the method
setFastConnectionFailoverEnabled(true) of the OracleDataSource class
in the oracle.jdbc.pool package before making the first getConnection()
request. When you enable FCF for the JDBC-thin client, the failover property applies
to every connection in the connection pool. Enabling FCF with JDBC-thin driver or
JDBC/OCI clients enables the connection pool to receive and react to all FAN events.
JDBC application developers can programmatically integrate with FAN by using a set
of APIs introduced in Oracle Database 11g release 2 (11.2). The Oracle RAC FAN APIs
enable application code to receive and respond to FAN event notifications sent by
Oracle RAC in the following ways:
•
Listening for Oracle RAC service down, service up, and node down events
•
Listening for load balancing advisory events and responding to them
Related Topics:
Oracle Database JDBC Developer’s Guide
Oracle Database 2 Day + Real Application Clusters Guide
Oracle Notification Service for JDBC-Thin Clients
FCF relies on Oracle Notification Service to propagate database events between the
connection pool and the Oracle RAC database. At run time, the connection pool must
be able to setup an Oracle Notification Service environment. Oracle Notification
Service (ons.jar) is included as part of the Oracle Client software. Oracle
Notification Service can be configured using either remote configuration or client-side
Oracle Notification Service daemon configuration. Remote Oracle Notification Service
subscription offers the following advantages:
•
Support for an All Java mid-tier software
•
An Oracle Notification Service daemon is not necessary on the client system, so
you do not have to manage this process
•
Simple configuration by way of a DataSource property
Configuring FCF for JDBC/OCI and JDBC-Thin Driver Clients
You can enable FCF for Universal Connection Pool or Implicit Connection Cache.
Oracle recommends using the Universal Connection Pool for Java because the Implicit
Connection Cache is deprecated. You can also use Oracle WebLogic Server Active
GridLink for Oracle RAC.
This procedure explains how to enable FCF for JDBC. For JDBC/OCI clients, if you
enable FCF, then do not use the method used with Oracle Database 11g release 2 (11.2)
of enabling FAN for OCI clients (setting notification to TRUE on the service), and
do not configure TAF, either on the client or for the service. You can also configure
Application Continuity and Transaction Guard.
To enable FCF, you must first enable the Universal Connection Pool, as described in
the following procedure:
1.
Create the connection pool and set
setFastConnectionFailoverEnabled(true).
5-10 Oracle Real Application Clusters Administration and Deployment Guide
Enabling Clients for Oracle RAC
The following example creates a connection pool and enables FCF. The ucp.jar
library must be included in the classpath of an application to use this example.
PoolDataSource pds = PoolDataSourceFactory.getPoolDataSource();
pds.setFastConnectionFailoverEnabled(true);
2.
Determine the ports to use for Oracle Notification Service remote subscriptions.
Use the following command to view the Oracle Notification Service configuration
on each node that is running Oracle Clusterware as in the following example:
srvctl config nodeapps -onsonly
The output of this command lists the local and remote ports configured for Oracle
Notification Service.
Note:
Oracle Notification Service configuration should have been automatically
completed during the Oracle Clusterware installation.
3.
Configure the remote Oracle Notification Service subscription.
When using the Universal Connection Pool, an application calls
setONSConfiguration for an OracleDataSource instance and specifies the
nodes and port numbers to use. The port numbers used for each node are the
same as the remote port displayed for each node in Step 2, as shown in the
following example. The ons.jar library must be included in the classpath of an
application to use this example.
pds.setONSConfiguration("nodes=racnode1:6200,racnode2:6200");
Applications that use remote Oracle Notification Service configuration must set
the oracle.ons.oraclehome system property to the location of ORACLE_HOME
before starting the application, for example:
java -Doracle.ons.oraclehome=$ORACLE_HOME ...
4.
Configure the connection URL.
A connection factory's connection URL must use the service name syntax when
using FCF. The service name is used to map the connection pool to the service.
The following example demonstrates configuring the connection URL:
pds.setConnectionFactoryClassName("oracle.jdbc.pool.OracleDataSource");
pds.setURL("jdbc:oracle:[email protected]//SCAN_name:service_name");...
Related Topics:
Oracle Database JDBC Developer’s Guide
Oracle Universal Connection Pool Developer’s Guide
Enabling JDBC Clients for Run-time Connection Load Balancing
Run-time connection load balancing requires the use of an Oracle JDBC driver and an
Oracle RAC database.
Workload Management with Dynamic Database Services 5-11
Enabling Clients for Oracle RAC
Oracle JDBC Universal Connection Pool and Oracle WebLogic Server Active GridLink
for Oracle RAC leverage the load balancing functionality provided by an Oracle RAC
database.
The Universal Connection Pool and Oracle WebLogic Server Active GridLink for
Oracle RAC are integrated to take advantage of Load Balancing Advisory information.
Oracle introduced the Universal Connection Pool for JDBC in Oracle Database 11g
release 11.1.0.7.0. Consequently, Oracle deprecated the existing JDBC connection pool,
the Implicit Connection Cache, which was introduced in Oracle Database 10g release 1
for use with Oracle RAC databases. In addition to Oracle Database 12c, you can also
use the Universal Connection Pool with Oracle Database 10g or Oracle Database 11g.
Run-time connection load balancing requires that FCF is enabled and configured
properly. In addition, the Oracle RAC load balancing advisory must be configured
with service-level goals for each service used by the connection pool. The connection
load balancing goal should be set to SHORT, for example:
srvctl modify service -db db_unique_name -service service_name
-rlbgoal SERVICE_TIME -clbgoal SHORT
Related Topics:
Configuring FCF for JDBC/OCI and JDBC-Thin Driver Clients
You can enable FCF for Universal Connection Pool or Implicit
Connection Cache.
Oracle Universal Connection Pool Developer’s Guide
Configuring JDBC-Thin Clients for Application Continuity for Java
The Replay data source (oracle.jdbc.replay.OracleDataSource) is a JDBCthin data source that Application Continuity requires for Java.
This data source serves as the connection factory that produces new physical JDBC
connections, for both Universal Connection Pool and Oracle WebLogic Server Active
GridLink for Oracle RAC data sources. The JDBC replay driver maintains a history of
calls during a client conversation with Oracle Database 12c, in collaboration with
Oracle Database. Following any outage of the session caused by a loss of database
service, planned or unplanned, under the direction of the database, the JDBC replay
driver attempts to rebuild the non-transactional and transactional database session
states, so that the outage appears as a delayed execution.
To use Application Continuity for Java and the JDBC replay driver, you must use an
Oracle Database 12c client and connect to an Oracle Database 12c database.
Application Continuity for Java is supported in the following configurations:
•
JDBC applications using Oracle JDBC Replay data source and using neither
Universal Connection Pool or Oracle WebLogic Server Active GridLink—typical
third-party, JDBC-based connection pools
•
JDBC applications using Universal Connection Pool data sources—standalone or
third-party application servers configured to use a Universal Connection Pool
data source
•
JDBC applications using only Oracle WebLogic Server Active GridLink but not
Universal Connection Pool data sources—typical Oracle WebLogic Server J2EE
cases
5-12 Oracle Real Application Clusters Administration and Deployment Guide
Enabling Clients for Oracle RAC
To configure JDBC-thin clients to use the JDBC Replay Driver:
1.
Ensure that you are using an application that is certified for replay.
2.
Use SRVCTL to create a service for use by the application, if one does not already
exist. Set the -failovertype parameter to TRANSACTION and the commit_outcome parameter to TRUE for this service.
3.
Configure the connection element using the replayDataSource object, as
shown in the following example:
replayDataSource rds = PoolDataSourceFactory.getreplayDataSource();
rds.setConnnectionPoolName("replayExample");
rds.setONSConfiguration("nodes=racnode1:4200,racnode2:4200");
rds.setFastConnectionFailoverEnabled(true);
rds.setConnectionFactoryClassName("oracle.jdbc.replay.OracleDataSource");
Connection conn = replayDataSource.getConnection();
4.
When connecting to the database, use a URL that can access all instances offering
the service.
Related Topics:
About Application Continuity
Application Continuity masks many recoverable database outages
(when replay is successful) from applications and users by restoring the
database session: the full session, including all states, cursors, variables,
and the last transaction if there is one.
Creating Services for Application Continuity and Transaction Guard
To configure services for Application Continuity, when you create a
service using SRVCTL, set the -failovertype parameter to
TRANSACTION and -commit_outcome to TRUE.
Configuring FCF for JDBC/OCI and JDBC-Thin Driver Clients
You can enable FCF for Universal Connection Pool or Implicit
Connection Cache.
Oracle Database JDBC Developer’s Guide
Oracle Universal Connection Pool Developer’s Guide
See Also:
Oracle Database JDBC Developer’s Guide for information about configuring
Transaction Guard without enabling Application Continuity
Configuring JDBC-Thin Clients for Transaction Guard
Transaction Guard provides a protocol and a generic tool for applications to use for atmost-once execution in case of planned and unplanned outages.
Applications use the logical transaction ID to determine the outcome of the last
transaction open in a database session following an outage. Without Transaction
Guard, end users or applications that attempt to retry operations following outages
can cause logical corruption by committing duplicate transactions or committing
transactions out of order.
Workload Management with Dynamic Database Services 5-13
Enabling Clients for Oracle RAC
Related Topics:
Oracle Database JDBC Developer’s Guide
Oracle Database Development Guide
Oracle Call Interface Programmer's Guide
Enabling OCI Clients for Fast Connection Failover
OCI clients can enable FCF by registering to receive notifications for Oracle RAC high
availability FAN events and responding when events occur. Using FCF improves the
session failover response time in OCI applications and also removes connections to
nonfunctioning instances from connection and session pools. FCF can be used in OCI
applications that also use TAF, OCI drivers (including your own connection pools),
OCI connection pool, and OCI session pools. FAN is posted over the Oracle
Notification Service for both high availability and load balancing events.
To use FCF, you must use a service with FAN enabled. FAN is published over Oracle
Notification Service. Client applications can also register callbacks that are used
whenever an event occurs. This reduces the time that it takes to detect a connection
failure.
During DOWN event processing, OCI:
•
Terminates affected connections at the client and returns an error
•
Removes connections from the OCI connection pool and the OCI session pool—
the session pool maps each session to a physical connection in the connection
pool, and there can be multiple sessions for each connection
•
Fails over the connection if you have configured TAF. If TAF is not configured,
then the client only receives an error if the instance it is connected to fails.
If your application is using TAF, then you must enable the TAF properties for the
service using SRVCTL or Oracle Enterprise Manager. Configure your OCI client
applications to connect to an Oracle RAC database using the configured service.
Note:
OCI does not manage UP events.
Configuring FCF for OCI Clients
OCI applications must connect to an Oracle RAC instance to enable HA event
notification. Furthermore, these applications must perform the following steps to
configure FCF for an OCI client:
1.
Configure the service for your OCI connection pool to enable FAN, connection
load balancing, and run-time connection load balancing, as shown in the
following example:
$ srvctl modify service -db crm -service ociapp.example.com -notification TRUE
2.
Link the application with a thread library.
3.
After linking with the thread library, the applications can register a callback that is
invoked whenever a FAN event occurs.
5-14 Oracle Real Application Clusters Administration and Deployment Guide
Enabling Clients for Oracle RAC
Related Topics:
Oracle Database Net Services Administrator's Guide
Oracle Call Interface Programmer's Guide
Enabling OCI Clients for Run-time Connection Load Balancing
As of Oracle Database 12c, OCI session pooling enables multiple threads of an
application to use a dynamically managed set of pre-created database sessions.
In connection pooling, the pool element is a connection, but in session pooling, the
pool element is a session. Oracle Database continually reuses the sessions in the
session pool to form nearly permanent channels to the instances, thus saving the
overhead of creating and closing sessions every time applications need them.
Run-time connection load balancing is enabled by default in an Oracle Database 11g
release 11.1, or later, client communicating with a server of Oracle Database 10g
release 10.2, or later. For Oracle RAC environments, session pools use service metrics
received from the Oracle RAC load balancing advisory1 through Fast Application
Notification (FAN) events to balance application session requests. The work requests
coming into the session pool can be distributed across the instances of Oracle RAC
offering a service, using the current service performance.
Configuring OCI Clients to Receive Load Balancing Advisory FAN Events
For Oracle RAC environments, session pools use service metrics received from the
Oracle RAC load balancing advisory through Fast Application Notification (FAN)
events to balance application session requests. To enable your application to receive
the service metrics based on the service time, ensure that you configure FAN, the load
balancing advisory goal (-rlbgoal parameter), and the connection load balancing
goal (-clbgoal parameter) for a service that is used by the session pool, as shown in
the following example:
$ srvctl modify service -db crm -service ociapp.example.com -rlbgoal SERVICE_TIME
-clbgoal SHORT -notification TRUE
Related Topics:
Oracle Call Interface Programmer's Guide
Configuring OCI Clients to use Transaction Guard
OCI supports FAN messages and Transaction Guard. FAN is designed to quickly
notify an OCI-based application of outages at the node, database, instance, service,
and public network levels.
Once notified of the failure, an application can leverage Transaction Guard to reliably
determine the outcome of the last in-flight transaction.
Transaction Guard avoids the costs of ambiguous errors that lead to user frustration,
customer support calls, and lost opportunities. Transaction Guard is safer and
performs better, with lower overheads, than home grown solutions for a known
outcome.
1
Run-time connection load balancing is basically routing work requests to sessions in a session pool that can best
serve the work. It comes into effect when selecting a session from an existing session pool. Thus, run-time
connection load balancing is a very frequent activity.
Workload Management with Dynamic Database Services 5-15
Enabling Clients for Oracle RAC
Related Topics:
Fast Application Notification
The Oracle RAC high availability framework monitors a database and its
services and sends event notifications using Fast Application
Notification (FAN).
Enabling Clients for Oracle RAC
Oracle Call Interface Programmer's Guide
Enabling ODP.NET Clients to Receive FAN High Availability Events
ODP.NET connection pools can subscribe to FAN HA notifications that indicate when
nodes, services, and service members are down.
After a DOWN event, Oracle Database cleans up sessions in the connection pool that go
to the instance and ODP.NET proactively removes connections that are no longer
valid. ODP.NET establishes additional connections to existing Oracle RAC instances if
the removal of invalid connections reduces the total number of connections to below
the value for the Min Pool Size parameter.
When connecting to Oracle Database 12c and later, ODP.NET uses Oracle Notification
Service, rather than Advanced Queuing.
Enable Fast Connection Failover for ODP.NET connection pools by subscribing to
FAN high availability events. To enable Fast Connection Failover, include "HA
Events=true" and "pooling=true" (the default value) in the connection string, as
shown in the following example where user_name is the name of the database user
and password is the password for that user:
con.ConnectionString =
"User Id=user_name;Password=password;Data Source=odpnet;" +
"Min Pool Size=10;Connection Lifetime=120;Connection Timeout=60;" +
"HA Events=true;Incr Pool Size=5;Decr Pool Size=2";
Related Topics:
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
Enabling ODP.NET Clients to Receive FAN Load Balancing Advisory Events
When connecting to Oracle Database 12c and later, ODP.NET uses Oracle Notification
Service, rather than Advanced Queuing.
Use the following procedure to enable ODP.NET clients or applications to receive
FAN load balancing advisory events:
1.
Enable Oracle Notification Service notifications by using SRVCTL, and set the
run-time load balancing goal, as shown in the following example:
$ srvctl modify service -db crm -service odpapp.example.com
-notification TRUE -clbgoal LONG -rlbgoal SERVICE_TIME
2.
Ensure Oracle Notification Service (ONS) is configured for FAN events including
run-time load balancing advice.
3.
To take advantage of load balancing events with ODP.NET connection pools, set
the load balancing attribute in the ConnectionString to TRUE (the default is
FALSE). You can do this at connect time. This only works if you are using
connection pools, or when the pooling attribute is set to TRUE which is the default.
5-16 Oracle Real Application Clusters Administration and Deployment Guide
Distributed Transaction Processing in Oracle RAC
The following example demonstrates how to configure the ConnectionString to
enable load balancing, where user_name is the name of the user and password
is the password:
con.ConnectionString =
"User Id=user_name;Password=password;Data Source=odpapp;" +
"Min Pool Size=10;Connection Lifetime=120;Connection Timeout=60;" +
"Load Balancing=true;Incr Pool Size=5;Decr Pool Size=2";
Note:
ODP.NET does not support connection redistribution when a node starts (UP
events). However, if you have enabled failover on the server-side, then
ODP.NET can migrate connections to newly available instances.
Related Topics:
srvctl modify service
Modifies service configuration.
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
Configuring ODP.NET Clients to use Transaction Guard
ODP.NET supports FAN messages and Transaction Guard. FAN is designed to
quickly notify an ODP.NET-based application of outages at the node, database,
instance, service, and public network levels.
Once notified of the failure, an application can leverage Transaction Guard to reliably
determine the outcome of the last in-flight transaction.
Transaction Guard avoids the costs of ambiguous errors that lead to user frustration,
customer support calls, and lost opportunities. Transaction Guard is safer and
performs better, with lower overheads, than home grown solutions for a known
outcome.
Related Topics:
Fast Application Notification
The Oracle RAC high availability framework monitors a database and its
services and sends event notifications using Fast Application
Notification (FAN).
Administering Services
Creating Services for Application Continuity and Transaction Guard
To configure services for Application Continuity, when you create a
service using SRVCTL, set the -failovertype parameter to
TRANSACTION and -commit_outcome to TRUE.
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
Distributed Transaction Processing in Oracle RAC
The X/Open Distributed Transaction Processing (DTP) architecture defines a standard
architecture or interface that enables multiple application programs (APs) to share
Workload Management with Dynamic Database Services 5-17
Distributed Transaction Processing in Oracle RAC
resources provided by multiple, and possibly different, resource managers (RMs). It
coordinates the work between APs and RMs into global transactions.
The following sections discuss how Oracle RAC supports global (XA) transactions and
DTP processing:
•
Overview of XA Transactions and Oracle RAC
•
Using Global Transactions and XA Affinity for XA Transactions
•
Using Services with XA Transactions on Oracle RAC
•
Configuring Services for XA Applications
•
Relocating Services in Administrator-Managed Databases
Overview of XA Transactions and Oracle RAC
A global (XA) transactioncan span Oracle RAC instances by default, allowing any
application that uses the Oracle XA library to take full advantage of the Oracle RAC
environment to enhance the availability and scalability of the application.
GTXn background processes support XA transactions in an Oracle RAC environment.
The GLOBAL_TXN_PROCESSES initialization parameter, which is set to 1 by default,
specifies the initial number of GTXn background processes for each Oracle RAC
instance. Use the default value for this parameter clusterwide to allow distributed
transactions to span multiple Oracle RAC instances. Using the default value allows the
units of work performed across these Oracle RAC instances to share resources and act
as a single transaction (that is, the units of work are tightly coupled). It also allows 2PC
requests to be sent to any node in the cluster.
Before Oracle RAC 11g release 1 (11.1), the way to achieve tight coupling in Oracle
RAC was to use distributed transaction processing (DTP) services, that is, services
whose cardinality (one) ensured that all tightly-coupled branches landed on the same
instance—regardless of whether load balancing was enabled. If the XA application
does not use suspend and resume on the same transaction branch, and does not issue
savepoints that span branches, then tightly coupled XA transactions no longer require
the special type of singleton services to be deployed on Oracle RAC databases. If your
application cannot determine whether a transaction branch has been suspended and
resumed, then the application must continue to use DTP services or preferably use XA
affinity.
XA affinity (placing all branches of the same XA transaction at the same Oracle RAC
instance) is a requirement when suspending and resuming the same XA branch or if
using savepoints across branches. It also provides much better performance because
different transactions can be balanced. XA affinity is available with Oracle WebLogic
Server Active GridLink for Oracle RAC, JDBC Universal Connection Pool, and Oracle
Tuxedo.
Note:
Occasionally, transaction processing monitors continue to require either XA
affinity or DTP services because the applications that use them suspend and
resume the same branch or use save points.
An external transaction manager, such as Oracle Services for Microsoft Transaction
Server (OraMTS), coordinates XA transactions. However, an internal Oracle
5-18 Oracle Real Application Clusters Administration and Deployment Guide
Distributed Transaction Processing in Oracle RAC
transaction manager coordinates distributed SQL transactions. They can both use
singleton services or uniform services. Singleton services provide XA affinity and can
be drained for maintenance, taking advantage of global transactions.
Related Topics:
Using Global Transactions and XA Affinity for XA Transactions
To provide improved application performance with distributed
transaction processing (DTP) in Oracle RAC, you can take advantage of
XA affinity.
Oracle Database Reference
Using Global Transactions and XA Affinity for XA Transactions
To provide improved application performance with distributed transaction processing
(DTP) in Oracle RAC, you can take advantage of XA affinity.
Using XA affinity, you can direct all branches of a distributed transaction to a single
instance in the cluster. To implement XA affinity you can use an application server
that provides XA affinity, such as WebLogic Server and Universal Connection Pool. If
your application server does not have XA affinity, then you can also use singleton
services across Oracle RAC.
Connection pools at the application server tier that load balance across multiple
connections to an Oracle RAC database use XA affinity to ensure that all tightlycoupled branches of a global distributed transaction run on only one Oracle RAC
instance. When using a connection pool with XA affinity, your services using XA can
span Oracle RAC. This is also true in distributed transaction environments using
protocols such as X/Open Distributed Transaction Processing or the Microsoft
Distributed Transaction Coordinator.
To enhance the performance of distributed transactions, you use services to manage
DTP environments. A singleton service runs on one Oracle RAC instance at time in an
Oracle RAC database. This service still allows draining for maintenance, so has better
high-availability characteristics than an older DTP service. To load balance across the
cluster, it is better to have several groups of smaller application servers with each
group directing its transactions to a single service, or set of services, than it is to have
one or two larger application servers. Using singleton services, global distributed
transactions performed through the services have their tightly-coupled branches
running on a single Oracle RAC instance. This has the following benefits:
•
The changes are available locally within one Oracle RAC instance when tightly
coupled branches need information about changes made by each other
•
Relocation and failover of services are fully supported using global transactions
•
By using more singleton services than there are Oracle RAC instances, Oracle
Database can balance the load by services across all of the Oracle RAC database
instances
Note: The DTP service attribute or XA affinity is required, if the application
suspend and resumes the same XA branch.
Workload Management with Dynamic Database Services 5-19
Distributed Transaction Processing in Oracle RAC
Using Services with XA Transactions on Oracle RAC
Most applications using XA on Oracle RAC can use uniform or (all preferred) services
with XA affinity provided by the connection pool or transaction processing monitor.
The application may also use singleton services to provide XA affinity.
When using singleton services, to leverage all of the instances in a cluster, create one
or more singleton services for each Oracle RAC instance that hosts distributed
transactions. Choose different services for application servers to balance the workload
among the Oracle RAC database instances. Because all of the branches of a distributed
transaction are on one instance, you can leverage all of the instances to balance the
load of many distributed transaction processing (DTP) transactions through multiple
singleton services, thereby maximizing application throughput.
If you add or delete nodes from your cluster database, then you may have to identify
and relocate services to ensure that you maintain optimum performance levels. Using
singleton services, current work can complete. If you use DTP services, then current
work is aborted.
You only need to use DTP services for XA applications that suspend and resume the
same branch. When you are using DTP, the same approach applies as that for
singletons, but you cannot drain the work when relocating services.
Configuring Services for XA Applications
To create distributed transaction processing (DTP) services for distributed transaction
processing, perform the following steps:
1.
Create a singleton service using Oracle Enterprise Manager or SRVCTL.
For an administrator-managed database, define only one instance as the preferred
instance. You can have as many available instances as you want, for example:
$ srvctl add service -db crm -service xa_01.example.com -preferred RAC01
-available RAC02,RAC03
For a policy-managed database, specify the server pool to use, and set the
cardinality of the service to SINGLETON, for example:
$ srvctl add service -db crm -service xa_01.example.com -serverpool dtp_pool
-cardinality SINGLETON
2.
Set the DTP parameter (-dtp) for the service to TRUE (the default value is
FALSE). You can use Oracle Enterprise Manager or SRVCTL to modify the DTP
property of the singleton service. The following example shows how to modify
the xa_01.example.com service using SRVCTL:
$ srvctl modify service -db crm -service xa_01.example.com -dtp TRUE
Note: If the application does require DTP services, then use the -dtp
parameter. If not, then use the preceding example with no -dtp parameter.
Related Topics:
srvctl add service
Adds services to a database and assigns them to instances.
5-20 Oracle Real Application Clusters Administration and Deployment Guide
Automatic Workload Repository
srvctl modify service
Modifies service configuration.
Relocating Services in Administrator-Managed Databases
Beginning with Oracle Real Application Clusters 11g release 1 (11.1), global
transactions and XA affinity replace the need for distributed transaction processing
(DTP) services.
Most XA deployments should be using global transactions with XA affinity for
improved load balancing and flexibility rather than the DTP attribute.
If the instance that provides a DTP service, for example XA_01, fails, then the service
fails over in the same manner as any other service. Because there is a requirement that
sessions exist on exactly one instance, however, the -f (force kill) option for database
sessions always applies.
If services migrate to other instances, then you might have to force the relocation of
the service back to the preferred instance after it is restarted to evenly re-balance the
load on all of the available hardware. You can use data from the GV
$ACTIVE_SERVICES view to determine whether you need to relocate the DTP
service.
Automatic Workload Repository
The Automatic Workload Repository (AWR) collects, processes, and maintains
performance statistics for the database.
The gathered data can be displayed in both reports and views. If you use services with
your database, then AWR tracks metrics at the service level.
Metrics can be measured against a variety of units, including time, transactions, or
database calls. For example, the number of database calls per second is a metric. Server
generated alerts can be placed on these metrics when they exceed or fail to meet userspecified thresholds. The database or system administrator can then respond, for
example, by:
•
Using the Oracle Database Resource Manager to configure the service level for
one service to have priorities relative to other services
•
Stopping overloaded processes
•
Modifying a service level requirement
•
Implementing recovery scenarios in response to service quality changes
Using AWR metrics and performance alerts enables you to maintain continued service
availability despite service level changes. It also enables you to measure the quality of
service provided by the database services.
The AWR ensures that the Oracle Clusterware workload management framework and
the database resource manager have persistent and global representations of
performance data. This information helps Oracle Database schedule job classes by
service and to assign priorities to consumer groups. If necessary, you can rebalance
workloads manually with either Oracle Enterprise Manager or SRVCTL. You can also
disconnect a series of sessions, but leave the service running.
Workload Management with Dynamic Database Services 5-21
Measuring Performance by Service Using the Automatic Workload Repository
Note:
Oracle does not recommend using the DBMS_SERVICE package for use with
services used by an Oracle RAC database. Use SRVCTL or Oracle Enterprise
Manager to create database services for Oracle RAC.
Related Topics:
Oracle Database 2 Day + Performance Tuning Guide
Oracle Database Performance Tuning Guide
Oracle Database PL/SQL Packages and Types Reference
Measuring Performance by Service Using the Automatic Workload
Repository
Services add a new dimension for performance tuning because workloads are visible
and measurable, and therefore resource consumption and wait times are attributable
by application.
Tuning by using "service and SQL" replaces tuning by "session and SQL" in the
majority of systems where all sessions are anonymous and shared.
The AWR maintains performance statistics that include information about response
time, throughput, resource consumption, and wait events for all services and work
that a database performs. Oracle Database also maintains metrics, statistics, wait
events, wait classes, and SQL-level traces for services. You can optionally augment
these statistics by defining modules within your application to monitor certain
statistics. You can also define the actions within those modules that business critical
transactions should execute in response to particular statistical values.
Enable module and action monitoring using the DBMS_MONITOR PL/SQL package.
For example, for connections that use the erp service, the following command enables
monitoring for the exceptions pay action in the payroll module:
EXECUTE DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE(SERVICE_NAME => 'ERP',
MODULE_NAME=> 'PAYROLL', ACTION_NAME => 'EXCEPTIONS PAY');
For connections that use the erp service, the following command enables monitoring
for all actions in the payroll module:
EXECUTE DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE(SERVICE_NAME => 'ERP',
MODULE_NAME=> 'PAYROLL', ACTION_NAME => NULL);
Use the DBA_ENABLED_AGGREGATIONS view to verify that you have enabled
monitoring for application modules and actions.
Statistics aggregation and tracing by service are global in scope for Oracle RAC
databases. In addition, these statistic aggregations are persistent across instance
restarts and service relocations for both Oracle RAC and noncluster Oracle databases.
The service, module, and action names are visible in V$SESSION, V
$ACTIVE_SESSION_HISTORY, and V$SQL views. The call times and performance
statistics are visible in V$SERVICE_STATS, V$SERVICE_EVENT, V
$SERVICE_WAIT_CLASS, V$SERVICEMETRIC, and V$SERVICEMETRIC_HISTORY.
When you enable statistics collection for an important transaction, you can see the call
5-22 Oracle Real Application Clusters Administration and Deployment Guide
Automatic Workload Repository Service Thresholds and Alerts
speed for each service, module, and action name at each database instance using the V
$SERV_MOD_ACT_STATS view.
The following sample SQL*Plus script provides service quality statistics for a five
second interval. You can use these service quality statistics to monitor the quality of a
service, to direct work, and to balance services across Oracle RAC instances:
SET PAGESIZE 60 COLSEP '|' NUMWIDTH 8 LINESIZE 132 VERIFY OFF FEEDBACK OFF
COLUMN service_name FORMAT A20 TRUNCATED HEADING 'Service'
COLUMN begin_time HEADING 'Begin Time' FORMAT A10
COLUMN end_time HEADING 'End Time' FORMAT A10
COLUMN instance_name HEADING 'Instance' FORMAT A10
COLUMN service_time HEADING 'Service Time|mSec/Call' FORMAT 999999999
COLUMN throughput HEADING 'Calls/sec'FORMAT 99.99
BREAK ON service_name SKIP 1
SELECT
service_name
, TO_CHAR(begin_time, 'HH:MI:SS') begin_time
, TO_CHAR(end_time, 'HH:MI:SS') end_time
, instance_name
, elapsedpercall service_time
, callspersec throughput
FROM
gv$instance i
, gv$active_services s
, gv$servicemetric m
WHERE s.inst_id = m.inst_id
AND s.name_hash = m.service_name_hash
AND i.inst_id = m.inst_id
AND m.group_id = 10
ORDER BY
service_name
, i.inst_id
, begin_time ;
Automatic Workload Repository Service Thresholds and Alerts
Service level thresholds enable you to compare actual service levels against required
levels of service. This provides accountability for the delivery or the failure to deliver
an agreed service level. The end goal is a predictable system that achieves service
levels. There is no requirement to perform as fast as possible with minimum resource
consumption; the requirement is to meet the quality of service.
AWR enables you to explicitly specify two performance thresholds for each service:
the response time for calls (ELAPSED_TIME_PER_CALL), and the CPU time for calls
(CPU_TIME_PER_CALL). The response time threshold indicates that the elapsed time
for each user call for each service should not exceed a certain value, and the CPU time
for calls threshold indicates that the time spent using the CPU for each call for each
service should not exceed a certain value. Response time is a fundamental measure
that reflects all delays and faults that might be blocking the call from running on
behalf of the user. Response time can also indicate differences in node power across
the nodes of an Oracle RAC database.
You must set these thresholds on each instance of an Oracle RAC database. The
elapsed time and CPU time are calculated as the moving average of the elapsed,
server-side call time. The AWR monitors the elapsed time and CPU time and
publishes AWR alerts when the performance exceeds the thresholds. You can schedule
actions using Oracle Enterprise Manager jobs for these alerts, or you can schedule
actions to occur programmatically when the alert is received. You can respond to these
alerts by changing the priority of a job, stopping overloaded processes, or by
Workload Management with Dynamic Database Services 5-23
Automatic Workload Repository Service Thresholds and Alerts
relocating, starting or stopping a service. This permits you to maintain service
availability despite changes in demand.
This section includes the following topics:
•
Example of Services and Thresholds Alerts
•
Enable Service_ Module_ and Action Monitoring
Example of Services and Thresholds Alerts
In this scenario, you need to check the thresholds for the payroll service. You can use
the AWR report to get this information. You should compare the results from reports
run over several successive intervals during which time the system is running
optimally. For example, assume that for servers accessed by a payroll application, the
AWR report runs each Thursday during the peak usage times of 1:00 p.m. to 5:00 p.m.
The AWR report contains the response time, or elapsed database time, and the CPU
consumption time, or CPU time, for calls for each server, including the payroll
service. The AWR report also provides a breakdown of the work done and the wait
times that are contributing to the response times.
Using DBMS_MONITOR, you set a warning threshold for the elapsed time per call for
the payroll service at 0.5 seconds (500000 microseconds). You also set a critical
threshold for the elapsed time per call for the payroll service at 0.75 seconds (750000
microseconds).
In this example, thresholds are added for the payroll service as follows:
EXECUTE DBMS_SERVER_ALERT.SET_THRESHOLD(
METRICS_ID => DBMS_SERVER_ALERT.ELAPSED_TIME_PER_CALL
, warning_operator => DBMS_SERVER_ALERT.OPERATOR_GE
, warning_value => '500000'
, critical_operator => DBMS_SERVER_ALERT.OPERATOR_GE
, critical_value => '750000'
, observation_period => 30
, consecutive_occurrences => 5
, instance_name => NULL
, object_type => DBMS_SERVER_ALERT.OBJECT_TYPE_SERVICE
, object_name => 'payroll');
You can verify the threshold configuration is set on all the instances using the
following SELECT statement:
SELECT METRICS_NAME, INSTANCE_NAME, WARNING_VALUE, CRITICAL_VALUE,
OBSERVATION_PERIOD FROM dba_thresholds ;
Enable Service, Module, and Action Monitoring
You can enable performance data tracing for important modules and actions within
each service. The performance statistics are available in the V$SERV_MOD_ACT_STATS
view. For example, you might decide to set the following:
•
For the ERP service, enable monitoring for the exceptions pay action in the
payroll module.
•
For the ERP service, enable monitoring for the all actions in the payroll module.
•
For the HOT_BATCH service, enable monitoring for all actions in the posting
module.
5-24 Oracle Real Application Clusters Administration and Deployment Guide
Using Oracle Services
The following commands show how to enable the module and action monitoring for
the services:
EXECUTE DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE(service_name => 'erp', module_name=>
'payroll', action_name => 'exceptions pay');
EXECUTE DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE(service_name => 'erp', module_name=>
'payroll');
EXECUTE DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE(service_name => 'hot_batch',
module_name =>'posting');
To verify monitoring is enabled for the service, module, and actions, use the following
SELECT statement:
COLUMN
COLUMN
COLUMN
COLUMN
SELECT
AGGREGATION_TYPE FORMAT A21 TRUNCATED HEADING 'AGGREGATION'
PRIMARY_ID FORMAT A20 TRUNCATED HEADING 'SERVICE'
QUALIFIER_ID1 FORMAT A20 TRUNCATED HEADING 'MODULE'
QUALIFIER_ID2 FORMAT A20 TRUNCATED HEADING 'ACTION'
* FROM DBA_ENABLED_AGGREGATIONS ;
The output is similar to the following:
AGGREGATION
-----------SERVICE_MODULE_ACTION
SERVICE_MODULE
SERVICE_MODULE
SERVICE
-------------------erp
erp
hot_batch
MODULE
---------payroll
payroll
posting
ACTION
------------exceptions pay
Using Oracle Services
To manage workloads or a group of applications, you can define services that you
assign to a particular application or to a subset of an application's operations. You can
also group work by type under services. For example, online users can use one service,
while batch processing can use another and reporting can use yet another service to
connect to the database.
Oracle recommends that all users who share a service have the same service level
requirements. You can define specific characteristics for services and each service can
represent a separate unit of work. There are many options that you can take advantage
of when using services. Although you do not have to implement these options, using
them helps optimize application performance.
Service Deployment Options
This section describes the following service deployment topics:
•
Service Usage in an Oracle RAC Database
•
Service Characteristics
•
Default Service Connections
•
Restricted Service Registration
Service Usage in an Oracle RAC Database
Services provide location transparency. A service name can identify multiple database
instances, and an instance can belong to multiple services. Several database features
use services for an Oracle RAC database:
This section includes the following topics:
Workload Management with Dynamic Database Services 5-25
Service Deployment Options
•
Oracle Clusterware Resources for a Service
•
Database Resource Manager Consumer Group Mappings for Services
•
Performance Monitoring by Service with AWR
•
Parallel Operations and Services
•
Oracle Streams and Oracle RAC
Oracle Clusterware Resources for a Service
Resource profiles are automatically created when you define a service. A resource
profile describes how Oracle Clusterware should manage the service and which
instance the service should failover to if the preferred instance stops. Resource profiles
also define service dependencies for the instance and the database. Due to these
dependencies, if you stop a database, then the instances and services are automatically
stopped in the correct order.
Database Resource Manager Consumer Group Mappings for Services
Services are integrated with Oracle Resource Manager, which enables you to restrict
the resources that users use to connect to an instance by using a service. Oracle
Resource Manager enables you to map a consumer group to a service so that users
who connect to an instance using that service are members of the specified consumer
group. Oracle Resource Manager operates at an instance level.
Performance Monitoring by Service with AWR
The metric data generated by Automatic Workload Repository (AWR) is organized
into various groups, such as event, event class, session, service, and tablespace metrics.
Typically, you view the AWR data using Oracle Enterprise Manager or AWR reports.
Related Topics:
Oracle Database Performance Tuning Guide
Parallel Operations and Services
By default, in an Oracle RAC environment, a SQL statement executed in parallel can
run across all of the nodes in the cluster. For this cross-node or inter-node parallel
execution to perform well, the interconnect in the Oracle RAC environment must be
sized appropriately because inter-node parallel execution may result in a lot of
interconnect traffic. To limit inter-node parallel execution, you can control parallel
execution in an Oracle RAC environment using the PARALLEL_FORCE_LOCAL
initialization parameter. By setting this parameter to TRUE, the parallel execution
servers can only execute on the same Oracle RAC node where the SQL statement was
started.
Services are used to limit the number of instances that participate in a parallel SQL
operation. When the default database service is used, the parallel SQL operation can
run on all available instances. You can create any number of services, each consisting
of one or more instances. When a parallel SQL operation is started, the parallel
execution servers are only spawned on instances which offer the specified service used
in the initial database connection.
PARALLEL_INSTANCE_GROUP is an Oracle RAC parameter that, when used with
services, lets you restrict parallel query operations to a limited number of instances.To
restrict parallel query operations to a limited number of instances, set the
5-26 Oracle Real Application Clusters Administration and Deployment Guide
Service Deployment Options
PARALLEL_INSTANCE_GROUP initialization parameter to the name of a service. This
does not affect other parallel operations such as parallel recovery or the processing of
GV$ queries.
Oracle Streams and Oracle RAC
Oracle Streams takes advantage of Oracle RAC features.
When Oracle Streams is configured in an Oracle RAC environment, each queue table
has an owning instance. If the instance that hosts a queue table fails, another instance
in the Oracle RAC database becomes the owning instance for the queue table, allowing
Oracle Streams to continue operating.
Also, on an Oracle RAC database, a service is created for each buffered queue. This
service always runs on the owner instance of the destination queue and follows the
ownership of this queue if the ownership switches because of instance startup,
instance shutdown, and so on. This service is used by queue-to-queue propagations.
Related Topics:
Oracle Streams Concepts and Administration
Service Characteristics
When you create new services for your database, you should define the automatic
workload management characteristics for each service. The characteristics of a service
include:
•
Service Name
•
Service Edition
•
Service Management Policy
•
Database Role for a Service
•
Instance Preference
•
Server Pool Assignment
•
Load Balancing Advisory Goal for Run-time Connection Load Balancing
•
Connection Load Balancing Goal
•
Distributed Transaction Processing
•
Failing Over OCI Clients with TAF
Service Name
Each service has a service name. The service name is used by clients to connect to one
or more instances. The service name must be unique throughout your system.
Service Edition
Edition-based redefinition of database objects enables you to upgrade an application's
objects while these objects are in use. You can set the edition attribute of a database
service when you create it, or modify an existing service to set the edition. When you
set the service edition, connections that use this service use this edition as the initial
session edition. If the service does not specify the edition name, then the initial session
edition is the database default edition.
Workload Management with Dynamic Database Services 5-27
Service Deployment Options
You can set the service edition using SRVCTL, as follows:
$ srvctl modify service –db hr –s crmsrv –edition e2
Service Management Policy
When you use Oracle Clusterware to manage your database, you can configure
startup options for each individual database service when you add the service using
the srvctl add service command with the -policy parameter.
If you set the management policy for a service to AUTOMATIC (the default), then the
service starts automatically when you start the database with SRVCTL. If you set the
management policy to MANUAL, then the service does not automatically start, and you
must manually start it with SRVCTL. A MANUAL setting does not prevent Oracle
Clusterware from monitoring the service when it is running and restarting it if a
failure occurs. Before Oracle RAC 11g release 2 (11.2), all services worked as though
they were defined with a MANUAL management policy.
Using CRSCTL to stop and restart Oracle Clusterware is treated as a failure and the
service is restarted if it was previously running.
Note:
When you use automatic services in an administrator-managed database,
during planned database startup, services may start on the first instances to
start rather than their preferred instances, provided that the started instances
are in the (combined) preferred and available services list.
Related Topics:
srvctl add service
Adds services to a database and assigns them to instances.
Database Role for a Service
If you configured Oracle Data Guard in your environment, then you can define a role
for services when you add or modify a service using SRVCTL and the -role
parameter with the appropriate command.
When you specify a role for a service, Oracle Clusterware automatically starts the
service only when the database role matches the role you specified for the service.
Valid roles are PRIMARY, PHYSICAL_STANDBY, LOGICAL_STANDBY, and
SNAPSHOT_STANDBY and you can specify more than one role for a service.
Note:
The service role only controls automatic startup of services. Using SRVCTL to
manually start a service will succeed even if the roles do not match.
Redo Apply (physical standby database) can run on all or some standby instances that
you can configure. This enables Redo Apply performance to scale, if necessary, by
adding additional standby instances.
If multiple databases in the cluster offer the same service name, then Oracle RAC
balances connections to that service across all such databases. This is useful for
standby and active Oracle Data Guard databases, but if you want client connections to
5-28 Oracle Real Application Clusters Administration and Deployment Guide
Service Deployment Options
a service to be directed to a particular database, then the service name must be unique
within the cluster (not offered by any other database).
Related Topics:
Oracle Data Guard Concepts and Administration
Instance Preference
When you define a service for an administrator-managed database, you define which
instances normally support that service using SRVCTL with the -preferred
parameter.
These are known as the preferred instances. You can also define other instances to
support a service if the service's preferred instance fails using SRVCTL with the available parameter. These are known as available instances.
When you specify preferred instances, you are specifying the number of instances on
which a service normally runs. This is the maximum cardinality of the service. Oracle
Clusterware attempts to ensure that the service always runs on the number of
instances for which you have configured the service. Afterwards, due to either
instance failure or planned service relocations, a service may be running on an
available instance.
If an instance fails, then you cannot control to which available instance Oracle
Clusterware relocates the services if there are multiple instances in the list. During a
planned operation, however, you can manually direct the service to any instance in
either the preferred or the available list not currently offering the service.
When a service moves to an available instance, Oracle Database does not move the
service back to the preferred instance when the preferred instance restarts because:
•
The service is running on the desired number of instances.
•
Maintaining the service on the current instance provides a higher level of service
availability.
•
Not moving the service back to the initial preferred instance prevents a second
outage.
You can, however, easily automate fail back to the preferred instance by using FAN
callouts.
Related Topics:
Tools for Administering Oracle RAC
Server Pool Assignment
When you define services for a policy-managed database, you assign the service to a
server pool in which the database is hosted using SRVCTL with the -serverpool
parameter.
You can define the service as either UNIFORM (running on all instances in the server
pool) or SINGLETON (running on only one instance in the server pool) using the cardinality parameter. For singleton services, Oracle RAC chooses on which
instance in the server pool the service is active. If that instance fails, then the service
fails over to another instance in the server pool. A service can only run in one server
pool and Oracle recommends that every server pool has at least one service.
Workload Management with Dynamic Database Services 5-29
Service Deployment Options
Note:
Oracle Database Quality of Service Management (Oracle Database QoS
Management) manages singleton services in a server pool, if the maximum
size of that server pool is one.
Related Topics:
Tools for Administering Oracle RAC
Load Balancing Advisory Goal for Run-time Connection Load Balancing
With run-time connection load balancing, applications can use load balancing
advisory events to provide better service to users. Oracle JDBC, Oracle Universal
Connection Pool for Java, OCI session pool, ODP.NET, and Oracle WebLogic Server
Active GridLink for Oracle RAC clients are automatically integrated to take advantage
of load balancing advisory events. The load balancing advisory informs the client
about the current service level that an instance is providing for a service. To enable the
load balancing advisory, use SRVCTL with the -rlbgoal parameter when creating or
modifying the service.
The load balancing advisory also recommends how much of the workload should be
sent to that instance. The goal determines whether connections are made to the service
based on best service quality (how efficiently a single transaction completes) or best
throughput (how efficiently a complete job or long-running query completes).
Connection Load Balancing Goal
Oracle Net Services provides connection load balancing to enable you to spread user
connections across all of the instances that are supporting a service.
For each service, you can use SRVCTL to define the method you want the listener to
use for load balancing by setting the connection load balancing goal, specified with the
-clbgoal parameter. Connections are classified as LONG (such as connection pools
and SQL*FORMS), which tells the listener to use session count, or SHORT, which tells
the listener to use response-time or throughput statistics.
If load balancing advisory is enabled (the -rlbgoal parameter does not equal NONE),
then connection load balancing attempts to use load balancing advisory (whether it is
set to SHORT or LONG). If load balancing advisory is set to SHORT, then it will use the
GOODNESS value of a service to try to prevent all connection requests from going to
one instance. If load balancing advisory is set to LONG, then it uses run queue
length if the service is non-uniform, or session count if there is uniform service
distribution.
Distributed Transaction Processing
Oracle XA applications have unique requirements. Oracle provides global transactions
across Oracle RAC. For best performance, use XA affinity (all branches at the same
instance) for most transactions, and global transactions when needed. You can use XA
affinity with connection pools, such as Universal Connection Pools and WebLogic
Server. You can also use singleton services that you create using SRVCTL. Use
SRVCTL, as well, to set the distributed transaction processing parameter (-dtp) to
TRUE if you are suspending and resuming the same Oracle XA branch. Do not use this
in general, however, because it does not offer rolling planned maintenance.
5-30 Oracle Real Application Clusters Administration and Deployment Guide
Service Deployment Options
Related Topics:
Distributed Transaction Processing in Oracle RAC
srvctl add service
Adds services to a database and assigns them to instances.
Default Service Connections
Your Oracle RAC database includes an Oracle database service identified by
DB_UNIQUE_NAME, if set, or DB_NAME or PDB_NAME, if not. This default service is
always available on all instances in an Oracle RAC environment, unless an instance is
in restricted mode. You cannot alter this service or its properties. Additionally, the
database supports the following two internal services:
•
SYS$BACKGROUND is used by the background processes only
•
SYS$USERS is the default service for user sessions that are not associated with
any application service
All of these services are used for internal management. You cannot stop or disable any
of these internal services to do planned outages or to failover to Oracle Data Guard.
Do not use these services for client connections.
Note:
You can explicitly manage only the services that you create. If a feature of the
database creates an internal service, you cannot manage it using the
information in this chapter.
Restricted Service Registration
This feature allows listener registration only from local IP addresses, by default, and
provides the ability to configure and dynamically update a set of IP addresses or
subnets from which registration requests are allowed by the listener.
Security is a high priority to all enterprises, and network security and controlling
access to the database is a critical component of overall security endeavours. Database
Instance registration with a listener succeeds only when the request originates from a
valid node. The network administrator can specify a list of valid nodes, excluded
nodes, or disable valid node checking. The list of valid nodes explicitly lists the nodes
and subnets that can register with the database. The list of excluded nodes explicitly
lists the nodes that cannot register with the database. The control of dynamic
registration results in increased manageability and security of Oracle RAC
deployments.
By default, valid node checking for registration (VNCR) is enabled. In the default
configuration, registration requests are only allowed from nodes within the cluster,
because they are redirected to the private subnet, and only nodes within the cluster
can access the private subnet. Non-SCAN listeners only accept registration from
instances on the local node. You must manually include remote nodes or nodes
outside the subnet of the SCAN listener on the list of valid nodes by using the
registration_invited_nodes_alias parameter in the listener.ora file or
by modifying the SCAN listener using SRVCTL, as follows:
$ srvctl modify scan_listener -invitednodes node_list -invitedsubnets subnet_list
Workload Management with Dynamic Database Services 5-31
Administering Services
Related Topics:
Oracle Database Net Services Administrator's Guide
Administering Services
You can create and administer services with Oracle Enterprise Manager and the
SRVCTL utility. The following sections describe how to perform service-related tasks
using these tools:
This section includes the following topics:
•
Overview of Service Administration
•
Administering Services with Oracle Enterprise Manager
•
Administering Services with SRVCTL
Note:
You can also use the DBMS_SERVICE package to create or modify services
and service attributes, but SRVCTL will override any settings made using this
package. The DBMS_SERVICE package is not recommended for use with
services used by an Oracle RAC database, nor when Oracle Restart is used,
nor when Oracle Clusterware is managing a single-instance database.
Overview of Service Administration
When you create and administer services, you are dividing the work that your
database performs into manageable units.
The goal of using services is to achieve optimal utilization of your database
infrastructure. You can create and deploy services based on business requirements.
Oracle Database can measure the performance for each service. Using the
DBMS_MONITOR package, you can define both the application modules within a
service and the individual actions for a module and monitor thresholds for these
actions, enabling you to manage workloads to deliver capacity on demand.
When you create new services for your database, you should define the automatic
workload management characteristics for each service, as described in "Service
Characteristics".
See Also:
Oracle Database Quality of Service Management User's Guide if you are using
Oracle Database QoS Management with your Oracle cluster for details on how
to configure the database services
In addition to creating services, you can:
•
Delete a service. You can delete services that you created. However, you cannot
delete or modify the properties of the default database service that Oracle
Database created.
5-32 Oracle Real Application Clusters Administration and Deployment Guide
Administering Services
•
Check the status of a service. A service can be assigned different roles among the
available instances. In a complex database with many services, you may not
remember the details of every service. Therefore, you may have to check the
status on an instance or service basis. For example, you may have to know the
status of a service for a particular instance before you make modifications to that
instance or to the Oracle home from which it runs.
•
Start or stop a service for a database or an instance. A service must be started
before it can be used for client connections to that instance. If you shut down your
database, for example, by running the SRVCTL command srvctl stop
database -db db_unique_name where db_unique_name is the name of the
database you want to stop, then Oracle Database stops all services for that
database. Depending on the service management policy, you may have to
manually restart the services when you start the database. Both the srvctl stop
database and srvctl stop service commands accept the -force option to
forcibly disconnect connections. To drain sessions for planned outages do not use
the -force option.
Note:
If Oracle Database QoS Management is enabled for the Oracle RAC database,
then the services are automatically restarted after they are stopped.
•
Map a service to a consumer group. You can map services to Resource Manager
Consumer groups to limit the amount of resources that services can use in an
instance. You must create the consumer group and then map the service to the
consumer group.
•
Enable or disable a service for a database or an instance. By default, Oracle
Clusterware attempts to restart a service automatically after failures. You can
prevent this behavior by disabling a service. Disabling a service is useful when
you must perform database or instance maintenance, such as when you are
performing an upgrade and you want to prevent connection requests from
succeeding.
•
Relocate a service to a different instance. You can move a service from one
instance to another instance to re-balance workloads, for example, after adding or
deleting cluster nodes.
Workload Management with Dynamic Database Services 5-33
Administering Services
Note:
•
When you use services, do not set a value for the SERVICE_NAMES
parameter; Oracle Database controls the setting for this parameter for the
services that you create and for the default database service. The service
features that this chapter describes are not directly related to the features
that Oracle Database provides when you set SERVICE_NAMES. In
addition, setting a value for this parameter may override some benefits of
using services.
•
Service status information must be obtained from SRVCTL or from the
service-related database views, such as dba_services.
•
If you specify a service using the DISPATCHERS initialization parameter,
it overrides any service in the SERVICE_NAMES parameter, and cannot be
managed. (For example, stopping the service with a SRVCTL command
does not stop users connecting with the service.)
Related Topics:
Oracle Database Quality of Service Management User's Guide
Enabling Clients for Oracle RAC
Oracle Database PL/SQL Packages and Types Reference
Administering Services with Oracle Enterprise Manager
The Cluster Managed Database Services page is the master page for beginning all
tasks related to services.
Access this page, as follows:
1.
In Oracle Enterprise Manager, go to the Cluster Database Home page.
See Also:
Oracle Database 2 Day DBA for details on logging in to Oracle Enterprise
Manager.
2.
From the Availability menu, select Cluster Managed Database Services to
display the Cluster Managed Database Services page.
3.
Enter or confirm the credentials for the Oracle RAC database and host operating
system and click Continue to display the Cluster Managed Database Services
page.
From the Cluster Managed Database Services page you can drill down to perform the
following tasks:
•
View a list of services for the cluster
•
View the instances on which each service is currently running
•
View the server pool and nodes offering the service in a policy-managed
environment
5-34 Oracle Real Application Clusters Administration and Deployment Guide
Administering Services
•
View the status for each service
•
Create or edit a service
•
Start or stop a service
•
Enable or disable a service
•
Perform instance-level tasks for a service
•
Delete a service
Note:
You must have SYSDBA credentials to access a cluster database. Cluster
Managed Database Services does not permit you to connect as anything other
than SYSDBA.
Related Topics:
Oracle Database 2 Day DBA
Oracle Database 2 Day + Real Application Clusters Guide
See Also:
•
Oracle Enterprise Manager online help for more information about
administering services with Oracle Enterprise Manager
•
Oracle Database 2 Day + Real Application Clusters Guide for more
information about using Oracle Enterprise Manager to manage services
Administering Services with SRVCTL
When you create a service using SRVCTL, you must start the service with a separate
SRVCTL command.
However, you may later have to manually stop or restart the service. You may also
have to disable the service to prevent automatic restarts, to manually relocate the
service, or obtain status information about the service. The following sections explain
how to use SRVCTL to perform the following administrative tasks:
•
Creating Services with SRVCTL
•
Creating Services for Application Continuity and Transaction Guard
•
Starting and Stopping Services with SRVCTL
•
Enabling and Disabling Services with SRVCTL
•
Relocating Services with SRVCTL
•
Obtaining the Status of Services with SRVCTL
•
Obtaining the Configuration of Services with SRVCTL
Workload Management with Dynamic Database Services 5-35
Administering Services
Creating Services with SRVCTL
To create a service with SRVCTL, use the srvctl add service command on the
command line.
Related Topics:
srvctl add service
Adds services to a database and assigns them to instances.
Creating Services for Application Continuity and Transaction Guard
To configure services for Application Continuity, when you create a service using
SRVCTL, set the -failovertype parameter to TRANSACTION and commit_outcome to TRUE.
When using Application Continuity and Transaction Guard with your applications,
you must configure a service. This section describes how to configure these
application services depending on the functionality you plan to implement.
Creating Services for Application Continuity
Additionally, you can set values for these other service parameters for Application
Continuity and load balancing:
•
-replay_init_time: Specifies how long, in seconds, you allow replay to start.
Oracle recommends that you choose a value based on how long you will allow
replay to be initiated. The default value is 300 seconds.
•
-retention: Specifies the time (in seconds) that the commit outcome
information is stored in the database. The default value is 86400 (1 day).
•
-session_state: After a COMMIT has executed, if the state was changed in
that transaction, then it is not possible to replay the transaction to reestablish that
state if the session is lost. When configuring Application Continuity, the
applications are categorized depending on whether the session state after the
initial setup is dynamic or static, and then whether it is correct to continue past a
COMMIT operation within a request.
–
Dynamic: (default) A session has a dynamic state if the session state changes
are not fully encapsulated by the initialization, and cannot be fully captured
in a callback at failover. Once the first transaction in a request commits,
failover is internally disabled until the next request begins. This is the default
mode that almost all applications should use for requests.
–
Static: (special—on request) A session has a static state if all session state
changes, such as NLS settings and PL/SQL package state, can be repeated in
an initialization callback. This setting is used only for database diagnostic
applications that do not change session state. Do not specify STATIC if there
are any non-transactional state changes in the request that cannot be
reestablished by a callback. If you are unsure what state to specify, use
DYNAMIC.
•
-failoverretry: Number of connection retries for each connection attempt;
recommended value is 30.
•
-failoverdelay: Delay in seconds between each connection attempt;
recommended value is 10.
5-36 Oracle Real Application Clusters Administration and Deployment Guide
Administering Services
•
-notification: FAN is highly recommended—set this value to TRUE to enable
FAN for OCI and ODP.Net clients.
•
-clbgoal: For connection load balancing, use SHORT when using run-time load
balancing.
•
-rlbgoal: For run-time load balancing, set to SERVICE_TIME.
To create a service for Application Continuity for a policy-managed Oracle RAC
database, use a command similar to the following, where racdb is the name of your
Oracle RAC database, app2 is the name of the service you are modifying, and
Svrpool1 is the name of the server pool in which the service is offered:
$ srvctl add service -db racdb -service app2 -serverpool Srvpool1
-failovertype TRANSACTION -commit_outcome TRUE -replay_init_time 1800
-retention 86400 -notification TRUE -rlbgoal SERVICE_TIME -clbgoal SHORT
-failoverretry 30 -failoverdelay 10
You can use SRVCTL to modify an existing service for Application Continuity, similar
to the following command, where racdb is the name of your Oracle RAC database,
and app1 is the name of the service you are modifying:
$ srvctl modify service -db racdb -service app1 -clbgoal SHORT
-rlbgoal SERVICE_TIME -failoverretry 30 -failoverdelay 10
-failovertype TRANSACTION -commit_outcome TRUE -replay_init_time 1800
-retention 86400 -notification TRUE
Creating Services for Transaction Guard
To enable Transaction Guard, but not Application Continuity, create the service using
SRVCTL and set only -commit_outcome TRUE.
You can use SRVCTL to modify an existing service to enable Transaction Guard,
similar to the following command, where racdb is the name of your Oracle RAC
database, and app2 is the name of the service you are modifying:
$ srvctl modify service -db racdb -service app2 -commit_outcome TRUE
-retention 86400 -notification TRUE
In the preceding example, the -retention parameter specifies how long, in seconds,
to maintain the history. Additionally the –notification parameter is set to TRUE,
enabling FAN events.
To use Transaction Guard, a DBA must grant permission, as follows:
GRANT EXECUTE ON DBMS_APP_CONT;
Related Topics:
Oracle Database Development Guide
Starting and Stopping Services with SRVCTL
For applications to connect using a server, the service must be started. If you stop a
service, then it is temporarily unavailable, but is still subject to automatic restart and
failover.
Enter the following SRVCTL syntax at the command line to start or stop a service:
$ srvctl start service -db db_unique_name [-service service_name_list]
[-instance inst_name] [-startoption start_options]
Workload Management with Dynamic Database Services 5-37
Administering Services
$ srvctl stop service -db db_unique_name -service service_name_list
[-instance inst_name] [-startoption start_options]
Enabling and Disabling Services with SRVCTL
If you disable a service, then Oracle Clusterware does not consider the service for
automatic startup, failover, or restart. You might disable a service when performing
application maintenance, to ensure the service is not accidentally restarted by Oracle
Clusterware until your maintenance operations are complete. To make the service
available for normal operation again, you enable the service.
Use the following SRVCTL syntax from the command line to enable and disable
services:
$ srvctl enable service -db db_unique_name -service service_name_list
[-instance inst_name]
$ srvctl disable service -db db_unique_name -service service_name_list
[-instance inst_name]
Relocating Services with SRVCTL
Run the srvctl relocate service command from the command line to relocate
a service. You might use this command when a service has failed over to an available
instance, but you want to move it back to the preferred instance after that instance is
restarted.
The following command relocates the crm service from instance apps1 to instance
apps3:
$ srvctl relocate service -db apps -service crm -oldinst apps1 -newinst apps3
The following command relocates the crm service from node1 to node3 using node
syntax:
$ srvctl relocate service -db apps -service crm -currentnode node1
-targetnode node3
Obtaining the Status of Services with SRVCTL
Run the srvctl status service command from the command line to obtain the
status of a service. For example, the following command returns the status of the
services that are running on the apps database:
$ srvctl status service -db apps
Service erp is running on nodes: apps02,apps03
Service hr is running on nodes: apps02,apps03
Service sales is running on nodes: apps01,apps04
Obtaining the Configuration of Services with SRVCTL
Run the srvctl config service command from the command line to obtain the
high availability configuration of a service. For example, the following command
returns the configuration of the erp service that is running on the apps database:
$ srvctl config service -db apps -service erp
Service name: erp
Service is enabled
Server pool: pool1
5-38 Oracle Real Application Clusters Administration and Deployment Guide
Global Services
Cardinality: 1
Disconnect: false
Service role: PRIMARY
Management policy: AUTOMATIC
DTP transaction: false
AQ HA notifications: true
Global: false
Commit Outcome: true
Failover type: TRANSACTION
Failover method: NONE
TAF failover retries: 30
TAF failover delay: 10
Connection Load Balancing Goal: LONG
Runtime Load Balancing Goal: SERVICE_TIME
TAF policy specification: NONE
Edition:
Pluggable database name:
Maximum lag time: ANY
SQL Translation Profile:
Retention: 86400 seconds
Replay Initiation Time: 1800 seconds
Session State Consistency: STATIC
Preferred instances: apps
Available instances:
Global Services
Oracle RAC supports database services and enables service-level workload
management across instances in a single cluster.
Global services provide dynamic load balancing, failover, and centralized service
management for a set of replicated databases that offer common services. The set of
databases may include Oracle RAC and non-clustered Oracle databases
interconnected by Oracle Data Guard, Oracle GoldenGate, or any other replication
technology.
When you create and use global services, the following workload management
features are available:
•
Ability to specify preferred and available databases for a global service
•
Handling of replication lag
•
Geographical affinity between clients and servers
•
Connection load balancing
•
Run-time load balancing
•
Inter-database service failover
•
Fast connection failover
•
Connect-time failover
•
Application Continuity
•
Transaction Guard
•
Backward compatibility with existing clients
Workload Management with Dynamic Database Services 5-39
Service-Oriented Buffer Cache Access
Note:
You can manage instance placement of a global service within an Oracle RAC
database with SRVCTL but you can only manage other global service
attributes with GDSCTL.
Related Topics:
Oracle Database Global Data Services Concepts and Administration Guide
Service-Oriented Buffer Cache Access
Service-oriented buffer cache access improves performance by managing data with the
service to which the data belongs.
Access of an object, over time, through a service is mapped and persisted to the
database, and this information can be used to improve performance. Blocks that are
accessed through the service are cached in the instances where the services are
running and, more importantly, the information is not cached where the services are
not running.
This information can also be used to pre-warm the cache prior to a service starting.
The service start-up can be triggered either by instance start-up or by service
relocation. Service-oriented buffer cache access provides consistent performance to
any user of that service because the blocks that the service user accesses are cached in
the new relocated instance.
Connecting to a Service: An Example
The following example illustrates how to create a service and then gives several
examples of connecting to that service using different client methods.
In this example the service is enabled for run-time load balancing, as follows:
•
Service Name: HR.example.com
–
Running on database named CRM
–
The system consists of 4 nodes
•
Specifying SERVICE_TIME as the value for the -rlbgoal parameter
•
SCAN address of the listener is rws3010104-scan.example.com
•
Listener port is 1585
The service has a cardinality of two, but if needed, can be offered by any of the CRM
database instances. The service configuration is as follows:
•
Preferred Instances: CRM1, CRM2
•
Available Instances: CRM3, CRM4
•
Specifying SHORT as the value for the -clbgoal parameter
The application using this service takes advantage of Application Continuity, so you
must set -failovertype and -commit_outcome. Use the default retention
parameters, but set a 10 second delay between connection attempts, and up to 40
retries before failing to get a connection.
5-40 Oracle Real Application Clusters Administration and Deployment Guide
Connecting to a Service: An Example
Creating the HR Service Using SRVCTL
Create the HR service using SRVCTL, as follows:
$ srvctl add service –db CRM –service HR.example.com –preferred CRM1,CRM2
–available CRM3,CRM4 –clbgoal SHORT –failovertype TRANSACTION
–commit_outcome TRUE –failoverdelay 10 –failoverretry 40
Start the HR.example.com service, as follows:
$ srvctl start service –db CRM –service HR.example.com
The service is now be available on up to two instances, and CRM1 and CRM2 are the
preferred instances.
Connecting to the HR Service from a JDBC Application
The application that connects to the HR service, in this example, is a JDBC application
using the JDBC Universal Connection Pool with the JDBC thin driver.
In this example, a URL is constructed specifying the thin-style service name format for
the database specifier. Fast Connection Failover is enabled, and remote Oracle
Notification Service is configured, where the Oracle Notification Service daemon on
the cluster listens on port 6200.
//import packages and register the driver
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import oracle.ucp.jdbc.PoolDataSourceFactory;
import oracle.ucp.jdbc.PoolDataSource;
PoolDataSource pds = PoolDataSourceFactory.getPoolDataSource();
//set the connection properties on the data source.
pds.setConnectionPoolName("FCFPool");
pds.setFastConnectionFailoverEnabled(true);
pds.setONSConfiguration("nodes=rws3010104-scan.example.com:6200");
pds.setConnectionFactoryClassName("oracle.jdbc.pool.OracleDataSource");
pds.setURL("jdbc:oracle:thin:@//rws3010104-scan.example.com:1585/HR.example.com");
pds.setUser("HR");
pds.setPassword("hr");
//Override any pool properties.
pds.setInitialPoolSize(5);
//Get a database connection from the datasource.
Connection conn = pds.getConnection();
// do some work
//return connection to pool
conn.close();
conn=null
Related Topics:
Oracle Universal Connection Pool Developer’s Guide
Workload Management with Dynamic Database Services 5-41
Connecting to a Service: An Example
5-42 Administration and Deployment Guide
6
Ensuring Application Continuity
Application Continuity is a feature that enables the replay, in a non-disruptive and
rapid manner, of a request against the database after a recoverable error that makes
the database session unavailable so an outage appears to the user as no more than a
delayed execution of the request.
The request can contain transactional and non-transactional work. After a successful
replay, the application can continue where that database session left off, instead of
having users left in doubt, not knowing what happened to their funds transfers, flight
bookings, and so on, and avoiding the need to reboot mid-tier servers to recover from
an overload of log ins when the application comes back online. With Application
Continuity, the end-user experience is improved by masking many outages, planned
and unplanned, without the application developer needing to attempt to recover the
request.
Without Application Continuity, it can be almost impossible for an application to
mask outages in a safe way, for reasons that include the following:
•
The state at the client remains at present time, with entered data, returned data,
and variables cached.
•
If a COMMIT has been issued, then the COMMIT failure message cannot be retrieved
if it is not received by the client or the application.
•
Checking the status of an in-doubt tansaction at a point in time is no guarantee
that it will not COMMIT later.
•
Non-transactional database session state that the application needs to operate is
lost.
•
If the request can continue, the database and the database session must be in the
right state.
With Application Continuity, however, Oracle Database, the Oracle drivers, and the
Oracle connection pools all collaborate to mask many outages in a safe and reliable
way.
Application Continuity improves developer productivity by attempting to mask
outages that can be masked. However, applications still must include error handling
for these cases:
•
Nonrecoverable errors, such as invalid input data. (Application Continuity applies
only to recoverable errors.)
•
Recoverable errors when replay has encountered a restriction, such as use of
concrete classes in the application, or when replay has not been able to restore the
client-visible state to that on which the client may have made decisions so far.
Ensuring Application Continuity 6-1
Fast Application Notification
Introduced in Oracle Database 12c Release 1 (12.1.0.1), Application Continuity
strengthens the fault tolerance of systems and applications that use an Oracle
database.
This chapter assumes that you are familiar with the major relevant concepts and
techniques of the technology or product environment in which you are using
Application Continuity, such as Oracle WebLogic Server, Oracle RAC, or Oracle
Active Data Guard (Oracle ADG).
This chapter includes the following topics:
•
About Application Continuity
•
Application Continuity Operation and Usage
•
Potential Side Effects of Application Continuity
•
Restrictions and Other Considerations for Application Continuity
•
Fast Application Notification
•
Transaction Guard for Improving Client Failover
•
Failing Over OCI Clients with TAF
Fast Application Notification
The Oracle RAC high availability framework monitors a database and its services and
sends event notifications using Fast Application Notification (FAN).
Oracle Database focuses on maintaining the highest possible service availability. In
Oracle RAC, services are designed to be continuously available with loads shared
across one or more instances. The Oracle RAC high-availability framework maintains
service availability by using Oracle Clusterware and resource profiles. Oracle
Clusterware recovers and balances services according to business rules and the service
attributes.
This includes the following topics:
•
Overview of Fast Application Notification
•
Managing Unplanned Outages
•
Managing Planned Maintenance
•
Fast Application Notification High Availability Events
•
Subscription to High Availability Events
•
Using Fast Application Notification Callouts
Related Topics:
Enabling Clients for Oracle RAC
Overview of Fast Application Notification
FAN provides immediate interrupt of clients following outages related to the
database, nodes, and networks.
6-2 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
FAN is essential to break clients out of TCP/IP timeouts immediately following
failures. FAN notifies clients immediately when resources become available and
initiates draining of database sessions so clients experience no outages during planned
maintenance. FAN also includes notifying configuration- and service-level
information that includes changes in service status.
The Oracle client drivers and Oracle connection pools respond to FAN events and take
immediate action. FAN UP and DOWN events apply to services, databases, instances,
networks, and nodes.
Note: FAN is supported from Oracle Database 10g release 2 (10.2), on.
Oracle connection pools, for example, use FAN to receive very fast notification of
failures, to balance connections following failures, and to balance connections again
after the failed components are repaired. So, when a service at an instance starts, the
connection pool uses the FAN event to route work to that resource, immediately.
When a service at an instance or node fails, the connection pool uses the FAN event to
immediately interrupt applications to recover. FAN is essential to prevent applications
from hanging on TCP/IP timeouts.
Importance of FAN
Applications can waste time in many critical ways:
•
Waiting for TCP/IP timeouts when a node fails without closing sockets, and for
every subsequent connection while that IP address is down.
•
Attempting to connect when services are down.
•
Not connecting when services resume.
•
Processing the last result at the client when the server goes down.
•
Attempting to execute work on sub-optimal nodes.
When a node fails without closing sockets, all sessions that are blocked in an I/O wait
(read or write) wait for tcp_keepalive. This wait status is the typical condition for
an application connected by a socket. Sessions processing the last result are even
worse off, not receiving an interrupt until the next data is requested. Using FAN
events eliminates applications waiting on TCP timeouts, time wasted processing the
last result at the client after a failure has occurred, and time wasted executing work on
slow, hung, or dead nodes.
For cluster configuration changes, the Oracle RAC high availability framework
publishes a FAN event immediately when a state change occurs in the cluster. Instead
of waiting for the application to time out against the database and detect a problem,
applications can receive FAN events and react immediately. With FAN, in-flight
transactions are immediately terminated and the client notified when the instance
fails.
FAN also publishes load balancing advisory events. Applications can take advantage
of the load balancing advisory FAN events to direct work requests to the instance in
the cluster that is currently providing the best service quality.
Oracle Database 12c release 2 (12.2) client drivers are FAN-aware, and FAN is enabled,
by default. This includes the JDBC Thin driver (12.2.0.1) and Oracle Data Provider for
Net (ODP.NET) drivers. A client driver can detect planned and unplanned FAN
events and take action beneath the application.
Ensuring Application Continuity 6-3
Fast Application Notification
For planned maintenance and applications using OCI or Pro* (and not using the OCI
session pool or Tuxedo), an application must check OCI_ATTR_SERVER_STATUS.
Add this check when sessions are returned to your own connection pool, and for idle
connections, regularly.
Following a FAN down event with planned maintenance, this attribute is set to
OCI_SERVER_NOT_CONNECTED. The application closes the connection after reading
this disconnected status. The session remains open for draining of active work until
the application closes, providing error-free failover.
You can take advantage of FAN events in the following ways:
•
Applications can use FAN without programmatic changes if you use an
integrated Oracle client. The integrated clients for FAN events include Oracle
JDBC Universal Connection Pool, ODP.NET connection pool, OCI session pool,
Oracle WebLogic Server Active Gridlink for Oracle RAC, and OCI and ODP.NET
clients. The integrated Oracle clients must be Oracle Database 10g release 2 (10.2)
or later to take advantage of the FAN high-availability events. The pooled clients
can also take advantage of the load balancing advisory FAN events.
•
You can configure third-party application containers, such as those provided by
Apache Tomcat and WebSphere, to use the built-in FAN support offered by using
the Universal Connection Pool in place of the default pool, which is certified as a
connection pool for third-party Java application servers including Apache Tomcat
and WebSphere.
•
Use the FAN-aware capability of the Oracle drivers by using standard interfaces
to test connections on get or release from the third-party connection pools in use by
third-party application servers or custom applications.
–
This solution applies to standard Java applications through the use of the
standard TNS connect string and ensures that the ons.jar and
simpleFAN.jar files are available on the application CLASSPATH.
–
For the OCI/OCCI driver, the OCI_ATTR_SERVER_STATUS server context
handle attribute is sensitive to FAN events and will return
OCI_SERVER_NOT_CONNECTED if the connection has been affected by a FAN
event.
•
You can implement FAN with server-side callouts on your database tier.
•
Applications can use FAN programmatically by using the JDBC and Oracle RAC
FAN application programming interface (API) or by using callbacks with OCI and
ODP.NET to subscribe to FAN events and to run event handling actions upon the
receipt of an event.
If you use one of the integrated clients listed in the first item of the preceding list, then,
for DOWN events, the disruption to the application is minimized because the FANaware client terminates the connections to the failed instance or node before they are
reused. Active work can be allowed to complete and, if there is a surviving instance,
then continuous service can be maintained for ongoing work. Any sessions active
when the instance or service stops are terminated and the application user is
immediately notified. Incomplete transactions can be protected by Application
Continuity, if it is enabled. Application users who request connections are directed to
available instances, only.
For UP events, when services and instances are started, new connections are created so
that the application can immediately take advantage of the extra hardware resources
or additional capacity.
6-4 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
To take advantage of FAN-aware capabilities in the drivers, as mentioned in the
previous list, the following is required:
•
For the thin Java driver, beginning with release 12.2, FAN is automatically
enabled by placing the ons.jar and simpleFAN.jar files on the CLASSPATH,
and by using the recommended TNS format (as shown in Example 6-1). Using the
recommended TNS format automatically configures ONS. Also with the Java thin
driver, FAN is supported for both planned and unplanned events. For unplanned
outages, the FAN interrupt is immediate. For planned maintenance, configure the
Java application servers or custom pools using standard interfaces to test
connections on get or release from third-party connection pools. For example,
TestConnectionsOnReserve, TestOnBorrow, or PreTest connections,
depending on the application server.
With this approach, when a FAN event is received during planned maintenance,
Fast Connection Failover closes sessions when they are tested, because the
application does not have a connection to the database at this time, and can retry
for a new connection. The connection tests may use isValid, isClosed,
isUsable, PingDatabase, or a SQL statement that is preceded by the hint /*+
CLIENT_CONNECTION_VALIDATION */.
•
For a SQL test, the SQL syntax must begin with the hint /*+
CLIENT_CONNECTION_VALIDATION */. At the time the SQL command runs,
the driver will drain the connection, if it is affected by the upcoming planned
maintenance. Connection pools, data sources, and, in the programmatic case,
customer applications, must all be ready to manage the recoverable error that
occurs when the SQL command runs, which usually closes the physical
connection.
Note: The SQL hint must be placed as the first non-comment token within the
SQL string to avoid changing current, driver-based SQL parsing. For example:
/*+ CLIENT_CONNECTION_VALIDATION */ SELECT 1 FROM DUAL;
•
Third-party Java application servers and Java applications can use the
PooledConnection standard interface when developing connection pools.
•
Beginning with the 11.2.0.3 release of the OCI/OCCI driver, when the
OCI_ATTR_SERVER_STATUS server context handle attribute returns
OCI_SERVER_NOT_CONNECTED, the application must terminate the connection.
Work will be drained for planned maintenance. The 12.2 release of the driver can
also detect OCISessionRelease and OCIRequestEnd when it receives a
planned DOWN event.
The following table describes the standard tests available for several of the more
common application servers:
Ensuring Application Continuity 6-5
Fast Application Notification
Table 6-1
Standard Tests for Some Common Application Servers
Application Server
Connection Test to Database
Oracle WebLogic Server
The tests offered include:
•
TestConnectionsonReserve:
•
isUsable, isValid, or PingDatabase
TestConnectionsOnCreate (SQL syntax):
/*+ CLIENT_CONNECTION_VALIDATION */ Select 1 from
dual;
Oracle WebLogic Server
Active Gridlink
IBM WebSphere
The test is embedded:
isUsable
PreTest connections (SQL syntax):
/*+ CLIENT_CONNECTION_VALIDATION */ Select user from dual;
RedHat JBoss
check-valid-connection-sql (SQL syntax):
Select 1 from dual;
Apache Tomcat
There are two tests available—testOnBorrow and
testOnReturn—and they both use SQL syntax to test the
connection to the database:
/*+ CLIENT_CONNECTION_VALIDATION */ Select 1 from dual;
Oracle recommends that you use the following format for supporting automatic
configuration of FAN:
Example 6-1
Automatic Configuration of FAN
alias =(DESCRIPTION =
(CONNECT_TIMEOUT=90)(RETRY_COUNT=20)(RETRY_DELAY=3)(TRANSPORT_CONNECT_TIMEOUT=3)
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=primary-scan)(PORT=1521)))
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=secondary-scan)(PORT=1521)))
(CONNECT_DATA=(SERVICE_NAME = gold-cloud)))
FAN callouts are server-side scripts or executables that run whenever a FAN event is
generated. You can design and build callouts to do many things. For example:
•
Log status information
•
Page DBAs or to open support tickets when resources fail to start
•
Automatically start dependent external applications that must be co-located with
a service
•
Change resource plans or shut down services when the number of available
instances for a policy-managed database decreases, for example, if nodes fail
6-6 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
•
Automate the fail back of a service to preferred instances for administratormanaged databases, if needed
FAN events are published using Oracle Notification Service and Oracle Streams
Advanced Queuing, the latter being continued for backward compatibility to previous
Oracle Database releases. The publication mechanisms are automatically configured as
part of your Oracle RAC installation. If you are using thin Java JDBC connections, then
the client can be automatically configured for Oracle Notification Service, by obtaining
the database-server Oracle Notification Service configuration from the database
connection. It is not necessary to configure Oracle Notification Service on the client.
Oracle Net Services listeners and Global Data Services (GDS) are integrated with FAN
events, enabling the listener and GDS to immediately de-register services provided by
the failed instance and to avoid erroneously sending connection requests to failed
instances.
If you specify the connection load balancing goal CLB_GOAL_SHORT for the service,
then the listener uses the load balancing advisory when the listener balances the
connection loads. When load balancing advisory is enabled, the metrics used for the
listener are finer grained.
Managing Unplanned Outages
You can assign services to one or more instances in an administrator-managed Oracle
RAC database or to server pools in a policy-managed database.
If Oracle RAC detects an outage, then Oracle Clusterware isolates the failed
component and recovers the dependent components. For services, if the failed
component is an instance, then Oracle Clusterware attempts to maintain the
cardinality of the service. If the service definition allows for failover and that is
necessary to maintain cardinality, then failover occurs.
FAN events can occur at various levels within the Oracle Database architecture and
are published through Oracle Notification Service and Oracle Streams Advanced
Queuing for backward compatibility with previous OCI clients. FAN callouts can also
be written to execute on the database server in response to FAN events.
Note:
Oracle Database does not run Oracle RAC callouts with guaranteed ordering.
Callouts are run asynchronously and they are subject to scheduling variability.
FAN is published from a surviving node when the failed node is out of service. The
location and number of instances in an Oracle RAC environment that provide a
service are transparent to applications. Restart and recovery are automatic, including
the restarting of the subsystems, such as the listener and the Oracle Automatic Storage
Management (Oracle ASM) processes, not just the database. You can use FAN callouts
to report faults to your fault management system and to initiate repair jobs.
It is a complex task for application developers to mask outages of a database session
(instance, node, storage or network, or any other related component) and, as a result,
errors and timeouts are often exposed to the end users leading to user frustration, lost
productivity, and lost opportunities. Together, FAN and Application Continuity mask
outages from users and applications by recovering the in-flight work for impacted
database sessions following outages. Application Continuity performs this recovery
beneath the application so that the outage appears to the application as a slightly
delayed execution of the request.
Ensuring Application Continuity 6-7
Fast Application Notification
Related Topics:
About Application Continuity
Application Continuity masks many recoverable database outages
(when replay is successful) from applications and users by restoring the
database session: the full session, including all states, cursors, variables,
and the last transaction if there is one.
Oracle Database Net Services Administrator's Guide
Managing Planned Maintenance
For repairs, upgrades, and changes that require you to isolate one or more instances or
nodes, Oracle RAC provides interfaces that relocate, disable, and enable services to
minimize service disruption to application users.
When you relocate a service, you indicate the service should run on another instance
temporarily. If you forcibly disable a service, then the service is stopped on all
database instances and is no longer available. Disabled services are not restarted
automatically. When a service is stopped or relocated, FAN is published with a
planned reason code, typically reason=user. Once you complete the operation, you
can return the service to normal operation or enable the service and then restart it.
When a service restarts, FAN is published with UP status codes.
Due to dependencies, if you manually shut down your database, then all of your
services for that database automatically stop. If you want your services to
automatically start when you manually restart the database, then you must set the
management policy of the service to automatic. If you want to shut down only one
instance of the database and you want the service to remain offered, then you can
either relocate the service using srvctl relocate service or stop the instance
using srvctl stop instance, which enables the service to automatically failover
according to its failover policy.
In either case, Oracle recommends that work running under the service drain at
request boundaries. The drain interval is specified as an attribute of the service or you
can provide a drain interval on the SRVCTL command line.
This section includes the following topics:
•
Managing Planned Maintenance Without User Interruption
•
Managing a Group of Services for Maintenance
Related Topics:
Service Management Policy
When you use Oracle Clusterware to manage your database, you can
configure startup options for each individual database service when you
add the service using the srvctl add service command with the policy parameter.
Managing Planned Maintenance Without User Interruption
You may have to stop database instances for maintenance, such as upgrading the
Oracle software, patching, and replacing hardware.
The steps in this section result in the least impact to users and requests are not
interrupted.
6-8 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
For planned maintenance, Oracle recommends that you drain requests over a
controlled time period from FAN-enabled Oracle connection pools. The service
attributes -drain_timeout and -stopoption control the drain time period, and
then how the service manages sessions that have not completed once this time period
expires. Requests that complete and then check back in to the pool or close, can be
directed to a new location that is not affected by the planned maintenance.
When using the Oracle Universal Connection Pool, sessions gradually drain,
according to the value of the -drain_timeout parameter, so there is minimal impact to
other work at the target instances. This also prevents overwhelming numbers of logins
when the service becomes available again.
Application Continuity provides additional cover, giving continuous service for those
requests that do not complete within the allotted drain time.
Using any FAN-aware pool with Fast Connection Failover configured (such as OCI
session pools, Oracle Universal Connection Pool, Oracle WebLogic Server Active
GridLink for Oracle RAC, or ODP.NET) allows sessions to drain at request boundaries
after receipt of the FAN planned DOWN event.
Requests are far more important than transactions because they enable the issued
work to complete. For draining requests, the Oracle Universal Connection Pool uses
the drain timeout to gradually drain, which prevents an overload of logins on the
instances drained, by slowly releasing the original sessions across the time period
rather than all at once. Gradual draining has the benefit of not disturbing the other
work ongoing at the target instances.
Both DRAIN_TIMEOUT and STOP_OPTION are service attributes that you can define
when you add the service or modify it after creation. You can also specify these
attributes using SRVCTL, which will take precedence over what is defined on the
service. You can specify the -drain_timeout and -stopoption parameters when
using the following SRVCTL commands:
•
srvctl add service
•
srvctl modify service
•
srvctl relocate service
•
srvctl stop service
•
srvctl stop database
•
srvctl stop instance
To manage planned maintenance without user interruption:
1. Use SRVCTL to relocate the service from an instance or, if you are using a uniform
or all-preferred service, then shut down the service on an instance. Use the -force
flag with the previously listed SRVCTL commands. You must use the -force flag
if you specify the -stopoption parameter on the command line when you run
either srvctl relocate service or srvctl stop service. For example:
$ srvctl relocate service –database mycdb01 –service myservice –drain_timeout 120
–stopoption IMMEDIATE –oldinst mycdb01_01 -force
The preceding command relocates the service named myservice01 from the
instance named mycdb01_01 to any instance on which it is configured to run.
Oracle Clusterware chooses this instance if you do not specify a target on the
command line, and waits two minutes (in this example) for any active sessions to
Ensuring Application Continuity 6-9
Fast Application Notification
drain, after which any sessions remaining on mycdb01_01 are forcibly
disconnected. The connection pool automatically releases a connection at a request
boundary.
2. The FAN planned DOWN event clears idle sessions from the connection pool
immediately and marks active sessions to be released at the next check-in. These
FAN actions drain the sessions from the instance without disrupting the users.
Existing connections on other instances remain usable, and new connections can be
opened to these instances if needed.
3. Not all sessions, in all cases, will check their connections into the pool. Oracle
recommends, as a best practice, to have a timeout period (by setting the drain_timeout parameter), after which the instance is forcibly shut down or the
service stopped, evicting any remaining client connections.
After the drain interval expires, the -stopoption parameter is implemented,
which you can define against a service or a database, as follows:
•
For a service, you can specify the following stop options: NONE,
TRANSACTIONAL, and IMMEDIATE
•
For a database, you can specify the following stop options: NORMAL,
TRANSACTIONAL, TRANSACTIONAL LOCAL, IMMEDIATE, and ABORT
The database stop options correlate to the service stop options, as follows:
NORMAL=NONE
TRANSACTIONAL/TRANSACTIONAL LOCAL=TRANSACTIONAL
IMMEDIATE/ABORT=IMMEDIATE
For those services that are configured to use Application Continuity, an attempt is
made to recover these remaining sessions, after they are terminated, masking the
outage from users and applications.
If you do not want Application Continuity to attempt to replay sessions, then
specify the -noreplay flag on the SRVCTL command line.
4. Once maintenance is complete, restart the instance and the service on the original
node.
5. The FAN UP event for the service informs the connection pool that a new instance
is available for use, allowing sessions to be created on this instance at next request
boundaries.
Related Topics:
About Application Continuity
Application Continuity masks many recoverable database outages
(when replay is successful) from applications and users by restoring the
database session: the full session, including all states, cursors, variables,
and the last transaction if there is one.
Managing a Group of Services for Maintenance
Many enterprises run a large number of services, whether it be many services offered
by a single database or instance, or many databases offering a few services running on
the same node.
6-10 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
You no longer need to run SRVCTL commands for each individual service but need
only specify the node name, database name, pluggable database name, or the instance
name for all affected services.
•
For example, if you want to stop all of the services running on a given node, then
you could use the following command:
$ srvctl stop service –node racnode01 –drain_timeout 60 –stopoption IMMEDIATE
The command stops all services running on racnode01, allowing a drain interval
of 60 seconds. After 60 seconds any remaining sessions are stopped immediately.
The 60-second drain timeout interval overrides any attribute setting on any of the
services.
The command could also be qualified to stop the databases on a node, as in the
following example:
$ srvctl stop database -node racnode01 -drain_timeout 60 –stopoption
TRANSACTIONAL
-failover –force
When you specify the -failover parameter:
–
All services are relocated, if possible, respecting the drain timeout interval
and the stop option specified.
–
Any services that cannot be failed over are stopped, using the stop option
specified.
–
Wait for the length of the drain timeout interval or until all sessions for
targeted services are removed, whichever is sooner.
–
All instances stop according to the stop option specified.
When you specify the –stopoption parameter:
–
Remaining services stop according to the drain timeout interval and stop
option specified.
–
Wait for the length of the drain timeout interval or until all sessions for
targeted services are removed, whichever is sooner.
–
The instance stops using the TRANSACTIONAL stop option.
This section includes the following topics:
•
Starting Services
•
Pluggable Database-Level Operations
•
Relocating Services
•
Stopping Services
Starting Services
You can use the srvctl start service command to start all services on a node,
all services offered by a database, all services offered by a pluggable database, or all
services offered on an instance or within a given server pool.
Ensuring Application Continuity 6-11
Fast Application Notification
You can also supply a list of services (a subset of all services) to the srvctl start
service command that you want to start. Additionally, you can provide a node
restriction, used in conjunction with the database option, for all services that can be
started on a particular node. You can restrict the srvctl start service command
to start only the parallel query service by specifying the -pq parameter.
The following examples illustrate how you can start services:
•
To start all of the services offered by a single pluggable database:
$ srvctl start service –db myRACCDB01 –pdb myPDB01 –startoption OPEN
To start all services on a given database and any of its pluggable databases:
$ srvctl start service –db myRACDB
To start only a subset of the services offered by a pluggable database:
$ srvctl start service –db myRACDB –pdb myPDB01 –service
"myFirstService,mySecondService,myThirdService"
To start a list of services on a given database, regardless of any pluggable
database with which they are associated:
$ srvctl start service –db myRACDB –service
"myFirstService,mySecondService,myThirdService"
To start all services for a database that can run on a given node:
$ srvctl start service –d myRACDB –node racnode01
Pluggable Database-Level Operations
You can use SRVCTL to manage services on pluggable databases.
•
To start all services for a pluggable database, for all instances or a single instance:
$ srvctl start service -db db_name -pdb pdb_name [-instance instance_name] [service service_name]
•
To stop all services for a pluggable database, for all instances or a single instance:
$ srvctl stop service -db db_name -pdb pdb_name [-instance instance_name] [service service_name] -drain_timeout
[-force [-stopoption]] [-noreplay]
Note: The -pdb pdb_name parameter is optional. If you omit the pluggable
database name, then the operation occurs for the entire container database (all
pluggable databases within this container).
Relocating Services
You can use the srvctl relocate service command to relocate services to a
target destination, which can be an instance, a node, a database, or a pluggable
database.
•
In the following command examples, all services are relocated from the named
database, pluggable database, instance, or node. The services will only relocate if
the target can support that service, as defined by the service configuration. Any
services that cannot be relocated remain at the original location. A placement error
6-12 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
is recorded against any services that could not be relocated, or were already
running at the new target. Services that fail to relocate remain running at their
original location, and any sessions remain active.
$ srvctl relocate service –database myRACCDB –oldinst RACCDB_01 –newinst
RACCDB_03
-drain_timeout 30 -force
or
$ srvctl relocate service –database myRACCDB –pdb myPDB01 –currentnode racnode01
–targetnode racnode02 -drain_timeout 30 -force –noreplay
The relocate operation starts the service in the new location prior to stopping the
service in its existing location.
•
If you do not specify a target destination, then Oracle Clusterware relocates all
services or specific services from the specified database, pluggable database,
instance, or node, as in the following examples:
$ srvctl relocate service –database myRACCDB –service "myService01,myService02"
-drain_timeout 30 -force
or
$ srvctl relocate service –database myRACCDB –pdb myPDB01 -drain_timeout 30
-force –noreplay
If there is no valid target available, then the service remains at the original
location and the sessions remain active. You must examine the services and stop
them if that is what you want to do.
When you relocate a service, it starts at the new location before it stops at the original
location. Oracle Clusterware can start that new instance or pluggable database as a
dependency. When specified, the -drain_timeout and -stopoption parameters
override the service attributes.
Stopping Services
You can use the srvctl stop service command to stop all services on a node, all
services offered by a database, all services offered by a pluggable database, or all
services offered on an instance or within a given server pool.
You can also supply a list of services (a subset of all services) that you want to stop to
the srvctl stop service command, and you can also restrict the srvctl stop
service command to stop only the parallel query service by specifying the -pq
parameter.
The following examples illustrate how you can stop services:
•
To stop all of the services offered by a single pluggable database:
$ srvctl stop service –db myRACCDB01 –pdb myPDB01 –drain_timeout 15 –stopoption
TRANSACTIONAL
To stop all services on a given database and any of its pluggable databases:
$ srvctl stop service –db myRACDB –drain_timeout 15 –stopoption IMMEDIATE
To stop only a subset of the services offered by a pluggable database:
Ensuring Application Continuity 6-13
Fast Application Notification
$ srvctl stop service –db myRACDB –pdb myPDB01 –service
"myFirstService,mySecondService,
myThirdService" –drain_timeout 60 –stopoption IMMEDIATE
Note: If you use the –wait YES SRVCTL command line parameter, then the
–stopoption parameter is not enforced until the entire drain timeout
interval has expired, even if all of the sessions have exited prior to this interval
completing.
Fast Application Notification High Availability Events
This section describes the information delivered in the FAN event to a callout
program.
FAN event types are listed following the example, and Table 6-2 describes name-value
pairs for the event parameters. The event type is always the first entry when you
receive FAN information through a callout, as in the following example:
SERVICEMEMBER VERSION=1.0
service=test.company.com database=ractest
instance=ractest11 host=ractest1_host0343_1 status=up reason=FAILURE
timestamp=2012-02-01 22:06:02 timezone=-07:00 db_domain=company.com
Note that the preceding example displays as one line.
FAN event types include:
DATABASE
INSTANCE
NODE
SERVICE
SERVICEMEMBER
SRV_PRECONNECT
SERVICEMETRICS
The DATABASE and INSTANCE types list the default database service as
DB_UNIQUE_NAME.
All events except for NODE events include a db_domain field.
Events of SERVICEMETRICS type are load balancing advisory events.
See Also: Table 5-1 for more information about load balancing events
Table 6-2
Event Parameter Name-Value Pairs and Descriptions
Parameter
Description
VERSION
Version of the event record. Used to identify release changes.
database
The unique name of the database supporting the service; matches
the initialization parameter value for DB_UNIQUE_NAME, which
defaults to the value of the DB_NAME initialization parameter.
instance
The name of the instance that supports the service; matches the
ORACLE_SID value.
6-14 Oracle Real Application Clusters Administration and Deployment Guide
Fast Application Notification
Table 6-2
(Cont.) Event Parameter Name-Value Pairs and Descriptions
Parameter
Description
host
The name of the node that supports the service or the node that
has stopped; matches the node name known to Cluster
Synchronization Services (CSS).
service
The service name; matches the name of the service as listed in
DBA_SERVICES and is domain-qualified as appropriate. Refer to
the following examples:
SERVICEMEMBER VERSION=1.0 service=swingbench
database=orcl instance=orcl_2 host=rwsbj13 status=up
reason=USER card=1 timestamp=2012-05-29 17:26:37
timezone=-07:00 db_domain=
SERVICEMEMBER VERSION=1.0 service=swingbench.example.com
database=orcl instance=orcl1 host=rwsbj09 status=up
reason=USER card=2 timestamp=2012-07-03 17:29:28
timezone=-07:00 db_domain=example.com
SERVICEMEMBER VERSION=1.0 service=swingbench.example.com
database=orcl instance=orcl2 host=rwsbj10 status=up
reason=USER card=1 timestamp=2012-07-03 17:29:18
timezone=-07:00 db_domain=example.com
status
Values are UP, DOWN, NODEDOWN (this only applies to the NODE
event type), NOT_RESTARTING, PRECONN_UP, PRECONN_DOWN,
and UNKNOWN.
Notes:
•
•
•
•
reason
When the node is down, the status is NODEDOWN, as opposed
to DOWN for other event types.
When STATUS=NODEDOWN and REASON=MEMBER_LEAVE, a
node has failed and is no longer part of the cluster.
When STATUS=NODEDOWN and REASON=PUBLIC_NW_DOWN,
the node is up but it is unreachable because the public
network is down.
Multiple public networks are supported by Oracle
Clusterware. The FAN event reflects this fact.
AUTOSTART, BOOT, DEPENDENCY, FAILURE, MEMBER_LEAVE,
PUBLIC_NW_DOWN, USER.
Notes:
•
•
•
For DATABASE and SERVICE event types,
REASON=AUTOSTART if, when the node started, the
AUTO_START resource attribute was set to restore, and the
resource was offline before the node started.
For DATABASE and SERVICE event types, REASON=BOOT if,
when the node started, the resource started because it was
online before the node started.
For SRVCTL and Oracle Enterprise Manager operations,
REASON=USER describes planned actions for such operations
as draining work.
Ensuring Application Continuity 6-15
Fast Application Notification
Table 6-2
(Cont.) Event Parameter Name-Value Pairs and Descriptions
Parameter
Description
cardinality
The number of service members that are currently active; included
in all SERVICEMEMBER UP events.
Following is an example of SERVICEMEMBER UP event:
SERVICEMEMBER VERSION=1.0 service=swingbench.example.com
database=orcl instance=orcl_2 host=mjkbj09 status=up
reason=USER card=1 timestamp=2012-07-12 14:46:46
timezone=-07:00 db_domain=example.com
incarnation
For NODEDOWN events; the new cluster incarnation. This value
changes each time a member joins or leaves the cluster.
Following is an example of a NODEDOWN event:
NODE VERSION=1.0 host=stru09 incarn=175615351 status=down
reason=member_leave timestamp=27-Jul-2010 14:49:32
timezone=-07:00
timestamp
The time according to Oracle Clusterware that an event occurs.
timezone
The time zone of Oracle Clusterware where the event occurred,
given as GMT +/-hh:mm.
Some of the FAN event record parameters have values that correspond to values
returned by the SYS_CONTEXT function using the default namespace USERENV, as
shown in Table 6-3.
Table 6-3
FAN Parameters and Matching Session Information
FAN Parameter
Matching Session Information
SERVICE
sys_context('userenv', 'service_name')
DATABASE_UNIQUE_NA
ME
sys_context('userenv', 'db_unique_name')
INSTANCE
sys_context('userenv', 'instance_name')
CLUSTER_NODE_NAME
sys_context('userenv', 'server_host')
Subscription to High Availability Events
Oracle RAC uses FAN to notify applications about configuration changes and the
current service level that is provided by each instance where the service is enabled. If
you are using an OCI client or an ODP.NET client to receive FAN events, then you
must enable the service used by that client to access the alert notification queue by
using SRVCTL with the -notification parameter.
Using Fast Application Notification Callouts
FAN callouts are server-side executables that Oracle RAC executes immediately when
high availability events occur.
You can use FAN callouts to automate activities when events occur in a cluster
configuration, such as:
6-16 Oracle Real Application Clusters Administration and Deployment Guide
About Application Continuity
•
Opening fault tracking tickets
•
Sending messages to pagers
•
Sending e-mail
•
Starting and stopping server-side applications
•
Maintaining an uptime log by logging each event as it occurs
•
Relocating low-priority services when high priority services come online
To use FAN callouts, place an executable in the Grid_home/racg/usrco directory
on every node that runs Oracle Clusterware. The executable must be able to run
standalone when called, with optional arguments, from another program. The
following is an example of the Grid_home/racg/usrco/callout.sh callout:
#! /bin/bash
FAN_LOGFILE= [your_path_name]/admin/log/'hostname'_uptime'.log
echo $* "reported="'date' >> $FAN_LOGFILE &
The previous example produces output similar to the following:
NODE VERSION=1.0 host=sun880-2 incarn=23 status=nodedown reason=public_nw_down
timestamp=08-Oct-2012 04:02:14 timezone=-08:00 reported=Fri Oct 8 04:02:14 PDT 2012
The contents of a FAN event record matches the current session of the user logged on
to the database, as shown in Table 6-3. The user environment (USERENV) information
is also available using OCI connection handle and descriptor attributes (using
OCIAttrGet()). Use this information to take actions on sessions that match the FAN
event data.
See Also:
Table 6-2 for information about the callout and event details
In general, events are only posted to user callouts on the node from which the event
originated. For example, if the database on node1 goes down, then the callout is
posted to node1, only. The only exceptions to this are node down and VIP down
events—these events are posted to all nodes, regardless of from where they originated.
Related Topics:
Oracle Call Interface Programmer's Guide
About Application Continuity
Application Continuity masks many recoverable database outages (when replay is
successful) from applications and users by restoring the database session: the full
session, including all states, cursors, variables, and the last transaction if there is one.
Application Continuity addresses the problem that arises when an application is
trying to access the database and the database instance becomes unavailable due to an
unplanned or planned outage (timeout, network outage, instance failure, repair,
configuration change, patch apply, and so on). Without Application Continuity in
place, database recovery does not mask outages to applications and end users. In such
scenarios, developers and users must cope with exception conditions, and users can be
left not knowing what happened to their funds transfers, time sheets, orders, bill
Ensuring Application Continuity 6-17
About Application Continuity
payments, and so on. Users might lose screens of uncommitted data, and must log in
again and reenter that data. In the worst cases, the administrator might be forced to
restart the middle tier to recover from an overwhelming number of logins.
With Application Continuity, if the database instance became unavailable, then
Application Continuity attempts to rebuild the session and any open transactions
using the correct states; and if the transaction committed and need not be resubmitted,
then the successful return status is returned to the application. If replay is successful,
then the request can continue safely without risk of duplication. If replay cannot
restore data that the application has already processed and potentially made decisions
on, then the database rejects the replay and the application receives the original error.
Application Continuity performs the recovery of in-flight transactions and database
session state, while ensuring the transaction idempotence provided by Transaction
Guard. Each database session is tagged with a logical transaction ID (LTXID), so the
database recognizes whether each replay committed any transactions, and if it did
commit any transactions, whether the work also ran to completion. While Application
Continuity attempts to replay, the replay appears to the application as a delayed
execution, or the application receives the commit response for the original transaction
(if the last transaction had completed before the outage).
Application Continuity is supported for Oracle RAC and Oracle Active Data Guard. It
is supported for both non-consolidated databases and Multitenant databases (with
failover at the pluggable database level). It is not currently supported for Golden Gate,
Logical Standby, third-party replication solutions, or DML redirection if using Oracle
Active Data Guard.
Related Topics:
Actions for Using Application Continuity
Key Concepts for Application Continuity
This section describes several terms and concepts that you must understand to use
Application Continuity.
The following terms are used throughout this chapter:
request
A request is a unit of work submitted from the application, such as a transaction. A
request typically corresponds to the SQL and PL/SQL, and other database calls, of a
single web request on a single database connection, and it is generally demarcated by
the calls made to check-out and check-in the database connection from a connection
pool.
recoverable error
A recoverable error is an error that arises due to an external system failure,
independent of the application session logic that is executing, such as a lost or invalid
connection. Recoverable errors occur following planned and unplanned outages of
foregrounds, networks, nodes, storage, and databases. The application receives an
error code that can leave the application not knowing the status of the last operation
submitted. Application Continuity reestablishes database sessions and resubmits the
pending work for the class of recoverable errors.
6-18 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Application Continuity does not resubmit work following call failures due to
nonrecoverable errors. An example of a nonrecoverable error that would not be
replayed is submission of invalid data values.
commit outcome
A transaction is committed by updating its entry in the transaction table. Oracle
Database generates a redo-log record corresponding to this update and writes out this
redo-log record. Once this redo-log record is written out to the redo log on disk, the
transaction is considered committed at the database. From the client perspective, the
transaction is considered committed when an Oracle message (called the commit
outcome), generated after that redo is written, is received by the client. However, if a
COMMIT has been issued, then the COMMIT failure message cannot be retrieved if it is
not received by the client or the application.
mutable functions
Mutable fuctions are non-deterministic functions that can obtain a new value every
time they are called, and thus their results can change frequently. Mutable functions
cause a problem for replay because the results can change at replay. Consider
sequence.NEXTVAL and SYSDATE, often used in key values. If a primary key is built
with values from these function calls, and is used in later foreign keys or other binds,
at replay the same function result must be returned.
Application Continuity provides mutable object value replacement at replay for
granted Oracle function calls to provide opaque bind-variable consistency. If the call
uses database functions that are mutable, including sequence.NEXTVAL, SYSDATE,
SYSTIMESTAMP, and SYSGUID, the original values returned from the function
execution are saved and are reapplied at replay.
session state consistency
After a COMMIT statement has executed, if state was changed in that transaction, it is
not possible to replay the transaction to reestablish that state if the session is lost.
When configuring Application Continuity, the applications are categorized depending
on whether the session state after the initial setup is static or dynamic, and thus
whether it is correct to continue past a COMMIT operation within a request.
•
A session has dynamic state if the session state changes are not fully encapsulated
by the initialization, and cannot be fully captured by FAILOVER_RESTORE or in
a callback at failover. After the first transaction completes, failover is internally
disabled until the next request begins. Session state may change during the course
of the request.
•
A session has a static state if all session state changes (for example, NLS settings
and PL/SQL package state) occur as part of initialization, and can be encapsulated
by FAILOVER_RESTORE or in a callback at failover. Static applications are those
that were able to use Transparent Application Failover (TAF) before Application
Continuity. Session state does not change during the course of the request.
Application Continuity Operation and Usage
This section explains how Application Continuity works, and how you can use it in
applications.
This section includes the following topics:
•
How Application Continuity Works for Applications
Ensuring Application Continuity 6-19
Application Continuity Operation and Usage
•
Actions for Using Application Continuity
•
Mutable Functions and Application Continuity
•
Administering Mutable Values
•
Session State Consistency
How Application Continuity Works for Applications
If a recoverable error occurs and if you enabled replay, then Application Continuity
attempts recovery of the database session.
The following figure is a graphical representation of how Application Continuity
works.
Figure 6-1
Application Continuity
1 Request
5 Response
UCP,
ODP.NET,
WebLogic,
OCI Session
Pool,
Tuxedo,
JDBC, and
OCI drivers
2 Calls
3 Fan
or error
5 User
4 Replay Calls
Database
Storage
To attempt to recover a database session following a recoverable error, Application
Continuity performs the following steps:
6-20 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Note: The steps to recover a database session apply for both unplanned and
planned outages, although specific steps vary depending on the type of
outage.
1.
The client application makes a request, which is passed to a middle tier (such as
the Universal Connection Pool (UCP), ODP.NET, WebLogic Server, OCI session
pool, Tuxedo, JDBC and OCI drivers, or third-party pool using UCP), or directly
to the database using the JDBC replay driver or OCI driver.
2.
The JDBC replay driver or OCI driver issues each call in the request.
3.
A FAN unplanned or planned down interrupt or recoverable error occurs.
FAN/FCF then aborts the dead physical session.
4.
Application Continuity begins the replay and does the following:
a.
Replaces the dead physical session with a new clean session.
b.
Prepares for replay by using Transaction Guard to determine the outcome of
the in-flight transaction, if one was open.
c.
FAILOVER_RESTORE=LEVEL1 restores the common initial session states.
Application Continuity uses a labeling callback or reconnect callback if an
application also sets initial session states that are not provided by
FAILOVER_RESTORE.
d.
Rebuilds the database session, recovering the transactional and nontransactional states, and validating at each step that the data and messages
seen by the client driver are the same as those that the client may have seen
and used to make a decision.
e.
Ends the replay and returns to runtime mode.
f.
Submits the last queued call.
This is the last call made when the outage was discovered. During replay,
only this call can execute a COMMIT. A COMMIT midway through rebuilding
the session aborts replay (excluding autonomous transactions).
5.
The response is returned to the application.
If replay succeeded, then the application can continue with the problem masked.
If not, then the application must handle the original error.
The behavior of Application Continuity after a communication failure depends on the
Oracle products and technologies involved. For example:
•
If you use Oracle RAC or an Oracle Active Data Guard farm, then, after the
connection is reestablished on another running instance, Application Continuity
attempts to rebuild the session and replay the last transaction if there is one in
flight.
•
If you use Oracle Active Data Guard and fail over to a standby site, then
Application Continuity connects to the failover instance and attempts to rebuild
the session and replay the last transaction there, if a transaction was in-flight.
(Application Continuity does not replay if the Oracle Active Data Guard
switchover or failover has lost data, and if this is not an Oracle Active Data Guard
reader farm with approved lags.)
Ensuring Application Continuity 6-21
Application Continuity Operation and Usage
•
If you are using Oracle RAC or Oracle RAC One Node and not using Oracle
Active Data Guard, and if an outage causes a break in all public networks or
causes the database or database session to shut down briefly, then Application
Continuity attempts to rebuild the session and replay the last transaction (if a
transaction was in flight) against the database after connectivity is restored.
Related Topics:
Using Application Continuity for Planned Maintenance
For planned maintenance, the recommended approach is to drain
requests from Oracle connection pools in combination with Application
Continuity for those requests that do not complete. Instances do need to
be stopped to switch over to the patched software.
Actions for Using Application Continuity
Application Continuity masks outages with few or no application changes when you
use the Oracle integrated stack.
Application Continuity is available for general use with the following Oracle
technologies:
•
ODP.NET, Unmanaged Driver
•
OCI Session Pool
•
Universal Connection Pool
•
WebLogic Server
•
JDBC Thin Oracle replay driver
•
Oracle Tuxedo
•
SQL*Plus
Application Continuity for Java is embedded in the Universal Connection Pool,
WebLogic data sources, including non-XA and XA data sources, and is available with
the thin JDBC replay driver, standalone (which is a JDBC replay driver without Oracle
connection pools, such as Apache Tomcat or a custom Java connection pool).
Application Continuity for OCI is embedded in SQL*Plus, OCI Session Pool. Oracle
Tuxedo for non XA data sources, and ODP.NET, Unmanaged Provider.
Application Continuity is embedded in Oracle connection pools. When you use the
Oracle connection pools, request boundaries are implicitly marked at check-out and
check-in, delimiting the size of each replay. When using third-party connection pools,
use UCP if Java, or you can add request boundaries, which are included on the JDK9
standard.
Support for Application Continuity is integrated into many Oracle applications, so the
features in such applications are used automatically if you set the Application
Continuity-related service attributes. For all applications, follow the steps described in
this section.
The main actions for ensuring transparent replay for an application are the following:
1.
Only if using Java, determine whether the application uses Oracle JDBC concrete
classes. For Application Continuity to be used, the deprecated concrete classes
must be replaced.
6-22 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Use the -acchk parameter with the ORAchk utility to verify whether an
application has any concrete classes. Use a connection without Application
Continuity if there is anything that should not be replayed. (Most applications
will be replayable.)
See Also: Oracle Autonomous Health Framework User's Guide for more
information about ORAchk
2.
Ensure that you have the necessary CPU and memory resources.
•
CPU: Application Continuity is managed on the client and server sides and
requires minimal CPU overhead to operate.
At the client, CPU is used to build proxy objects and for garbage collection
(GC).
At the server, CPU is used for validation. CPU overhead is reduced for
platforms with current Intel and Sparc chips where validation is assisted in
the hardware.
•
Memory: When using Application Continuity, the replay driver requires
more memory than the base driver because the calls are retained until the end
of a request. At the end of the request, the calls are released to the garbage
collector. This action differs from the base driver that releases closed calls.
The memory consumption of the replay driver depends on the number of
calls per request. If this number is small, then the memory consumption of the
replay driver is less, and comparable to the base driver.
To obtain the best performance, you must set the same value for both the Xmx and -Xms parameters on the client. For example, if there is sufficient
memory, then allocate 4 to 8 GB (or more) of memory for the Virtual Machine
(VM), for example, by setting -Xms4g for 4 GB. If the -Xms parameter has a
lower value, then the VM also uses a lower value from the operating system,
and performance might suffer and garbage collection operations increase.
3.
Determine whether the application borrows and returns connections from the
connection pool, for example WebLogic Server Pool, Universal Connection Pool,
OCI Session Pool, Oracle Tuxedo request, or ODP.NET connection pool, for each
request, or whether to add beginRequest and endRequest APIs to the
application's own connection pool to identify request boundaries for Java, only.
Important: Do not use the beginRequest and endRequest Java API calls
anywhere other than at request boundaries (borrow and return connections
from your connection pool). endRequest indicates that the request is
complete, and that it is now stateless. Replay starts from the next
beginRequest. If there is prior state, it must be reestablished using
FAILOVER_RESTORE or callback.
4.
Application Continuity replays your states, all states in a request. If the
application sets states before vending connections, FAILOVER_RESTORE or a
callback is needed. When using Oracle WebLogic Server or the Universal
Connection Pool, use FAILOVER_RESTORE or connection labeling. When using
OCI session pool, Oracle Tuxedo or ODP.NET, use FAILOVER_RESTORE, and
only add the TAF callback if it is needed. The labeling is used for both runtime
and replay.
Ensuring Application Continuity 6-23
Application Continuity Operation and Usage
5.
Determine whether the application requires, and therefore needs to configure
keeping original values for, SYSDATE, SYSTIMESTAMP, and SYS_GUID and
sequences during failover.
6.
Assess the application style for the session_state_consistency value, and
set the appropriate value on the service:
7.
•
If session_state_consistency is Dynamic, the application changes the
environment or settings during the request. Replay is disabled after the first
COMMIT until the beginning of the next request. Dynamic is the default mode,
appropriate for most applications.
•
If session_state_consistency is Static, the application never changes
the session state after initial setup. This mode is typical for database agnostic
applications that do not use PL/SQL state and do not use ALTER part-way
through transactions. Use this mode with caution, and only for "static"
applications.
Determine if any requests in the application should not be replayed.
For example, replay may need to be disabled for requests using external PL/SQL
actions.
8.
Follow these configuration guidelines:
•
Use Oracle Database 12c release 1 (12.1.0.1), or later, for Java. Use Oracle
Database 12c release 2 (12.2), or later, for OCI-based applications..
•
For .NET applications, use ODP.NET, Unmanaged Driver 12.2, or later,
connecting to an Oracle Database 12c Release 2 (12.2) or later. By default,
Application Continuity is enabled for ODP.NET applications in this
configuration.
•
For Java-based applications, use Universal Connection Pool 12.1 (or later) or
WebLogic Server 12.1.2 (or later) configured with the JDBC Replay data
source; or for third party applications, including third party JDBC pools, use
JDBC replay driver. For IBM WebSphere, Apache Tomcat, RedHat Spring,
and custom Java solutions, the most effective solution is to use UCP as the
pooled data source.
Custom Java pools and standalone Java applications can also use the JDBC
Replay data source directly. When using custom Java pools and standalone
applications, add the beginRequest and endRequest calls.
•
If the application does not borrow and return from the Oracle connection
pools, explicitly mark request boundaries. For example, if using custom JDBC
pools, or other pools, then call beginRequest at check-out and call
endRequest at check-in. These APIs can also be used for standalone JDBC
applications without a connection pool.
•
Enable FAN for fast interrupt on errors. This is essential to eliminate a TCP
hang occurring before the failover can start. In 12.2 FAN is built into the JDBC
and OCI drivers and is on by default for Java.
•
Use a database service to connect; never use a SID or an instance name, or the
administration service that is the DB_NAME or DB_UNIQUE_NAME.
•
Use a connection string that sets retries for new incoming connections and a
delay between these retries.
6-24 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Recommended format supporting automatic configuration of FAN:
alias =(DESCRIPTION =
(CONNECT_TIMEOUT=90) (RETRY_COUNT=20)(RETRY_DELAY=3)
(TRANSPORT_CONNECT_TIMEOUT=3)
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=primary-scan)(PORT=1521)))
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=secondary-scan)(PORT=1521)))
(CONNECT_DATA=(SERVICE_NAME = gold-cloud)))
•
For the service, set FAILOVER_TYPE to TRANSACTION, COMMIT_OUTCOME to
TRUE, and Notification to TRUE. Optionally to find the best connections
to use, set GOAL to SERVICE_TIME and CLB_Goal to Short.
•
Grant permission on the Transaction Guard package, DBMS_APP_CONT, to the
database users that fail over using Application Continuity, as follows:
GRANT EXECUTE ON DBMS_APP_CONT TO user_name;
•
Use Application Continuity Check Coverage (with the ORAchk utility) to
report the percentage of requests that are fully protected by Application
Continuity, and the location of those requests that are not fully protected. Use
this coverage check before deployment and after application changes.
Developers and management will know how well protected an application
release is from failures of the underlying infrastructure. If there is a problem,
then it can be fixed before the application is released, or waived knowing the
level of coverage.
See Also:
•
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows for
more information about .NET applications development.
•
Oracle Database JDBC Developer’s Guide for more information about
developing applications that include Application Continuity for Java
This section includes the following topics:
•
When Application Continuity is Transparent
•
Configuring Oracle Application Continuity
•
Configuring Oracle Database for Application Continuity
•
Establishing the Initial State Before Application Continuity Replays
•
Delaying the Reconnection in Application Continuity
•
Using Application Continuity with SQL*Plus
•
Using Application Continuity for Planned Maintenance
•
Running Without Application Continuity
Ensuring Application Continuity 6-25
Application Continuity Operation and Usage
•
Disabling Replay in Application Continuity
•
Terminating or Disconnecting a Session Without Replay
Related Topics:
Oracle Autonomous Health Framework User's Guide
Mutable Functions and Application Continuity
When a request is replayed, the default and desired treatment of
mutable objects can vary.
Session State Consistency
Session state consistency describes how non-transactional state is
changed during a request.
Session State Consistency
Session state consistency describes how non-transactional state is
changed during a request.
Disabling Replay in Application Continuity
By default, replay occurs following a recoverable error.
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
Oracle Database JDBC Developer’s Guide
Oracle Universal Connection Pool Developer’s Guide
Oracle Database 2 Day + Real Application Clusters Guide
Oracle ORAchk and EXAchk User’s Guide
When Application Continuity is Transparent
Application Continuity is transparent (no application code changes) for ODP.NET
applications, OCI applications, Tuxedo applications, and J2EE applications that use
standard JDBC, and that use Oracle connection pools (UCP, OCI, or ODP), and
SQL*Plus. For applications with external actions (for example, autonomous
transactions or using UTL_HTTP to issue an SOA call), Application Continuity is
transparent when the application is satisfied with replaying external actions, such as
resending email, auditing, and transferring a file for example.
For non-Oracle pools, including third-party Java containers, in which Application
Continuity is not transparent, the following infrastructure changes may be needed:
•
If the connection pool or container does not use an Oracle connection pool, then
many third parties fully support replacing the connection pool with the Universal
Connection Pool. This includes IBM WebSphere and Apache Tomcat.
Alternatively—for Java applications, only—the application can add its own
request boundaries.
•
If the application has requests that the application does not want repeated, then
the application can explicitly call an API to disable replay for those requests. The
simplest way to do this is to use a connection to a service that does not have
FAILOVER_TYPE set to TRANSACTION. Such calls are likely to be isolated to one
or a few specialized pieces of application code.
6-26 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Configuring Oracle Application Continuity
If you are using Java, then you must use the
oracle.jdbc.replay.OracleDataSourceImpl data source to obtain JDBC
connections.
This data source supports all the properties and configuration parameters of all the
Oracle JDBC data sources, for example, the
oracle.jdbc.pool.OracleDataSource.
For OCI based applications including SQL*Plus and ODP.NET, the OCI driver 12.2,
and later, supports Application Continuity.
You must remember the following points while using the connection URL:
•
If the REMOTE_LISTENER setting for the database does not match the addresses in
the ADDRESS_LIST at the client, then it does not connect, showing services
cannot be found. So, the REMOTE_LISTENER setting for the database must
match the addresses in the ADDRESS_LIST at the client:
–
If REMOTE_LISTENER is set to the SCAN names, then the ADDRESS_LIST
must use SCAN VIPs.
–
If the connect string uses the SCAN Name, then REMOTE_LISTENERS must
be set to the SCAN name.
–
If the connect string uses an ADDRESS_LIST of host VIPs, then
REMOTE_LISTENERS must be set to an address list that includes all SCAN
VIPs and all host VIPs
Note:
Use SCAN for location independence, so that you do not need to reconfigure
the client when you add or delete nodes, or when databases change to running
on different nodes.
•
Set RETRY_COUNT, RETRY_DELAY, CONNECT_TIMEOUT, and
TRANSPORT_CONNECT_TIMEOUT parameters in the connection string. These
settings improve acquiring new connections at runtime, at replay, and during
work drains for planned outages.
The CONNECT_TIMEOUT parameter is equivalent to the
SQLNET.OUTBOUND_CONNECT_TIMEOUT parameter in the sqlnet.ora file and
applies to the full connection. The TRANSPORT_CONNECT_TIMEOUT parameter
applies per address.
Set CONNECT_TIMEOUT to a high value to prevent an overabundance of log ins.
Low values can result in log in storms to the application or server pool cancelling
and retrying. Do not set (RETRY_COUNT+1)*RETRY_DELAY or
CONNECT_TIMEOUT larger than your response time SLA. The application must
either connect or receive an error within the response time SLA.
These are general recommendations for configuring the connections for high
availability. Do not use Easy*Connect because this has no high-availability
capabilities.
When the connect string uses host VIPs, then REMOTE_LISTENERS must include
host VIPs. When the connect string uses the SCAN name, then
Ensuring Application Continuity 6-27
Application Continuity Operation and Usage
REMOTE_LISTENERS must be set to the SCAN name, or include the SCAN VIPs
and the host VIPs. Therefore, REMOTE_LISTENERS must be set to the SCAN
name unless any clients use host VIPs in their connect strings, in which case
REMOTE_LISTENERS must be set to an ADDRESS_LIST of all SCAN VIPs and all
host VIPs.
Following is an example of TNS entry. This is the required TNS format for ONS
(the transport system for FAN) to be auto configured. FAN is recommended with
Application Continuity to provide the immediate detection.
alias =(DESCRIPTION =
(CONNECT_TIMEOUT=120) (RETRY_COUNT=20)(RETRY_DELAY=3)
(TRANSPORT_CONNECT_TIMEOUT=3)
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=primary-scan)(PORT=1521)))
(ADDRESS_LIST =
(LOAD_BALANCE=on)
( ADDRESS = (PROTOCOL = TCP)(HOST=secondary-scan)(PORT=1521)))
(CONNECT_DATA=(SERVICE_NAME = gold-cloud)))
Related Topics:
Oracle Database Net Services Reference
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
Configuring Oracle Database for Application Continuity
Your Oracle Database configuration must include the following to use Application
Continuity:
•
If you are using Oracle Real Application Clusters (Oracle RAC) or Oracle RAC
One Node, Oracle Data Guard, or Oracle Active Data Guard, then ensure that
FAN is configured with Oracle Notification System (ONS) to communicate with
Oracle Database 12c pools and drivers.
•
Set the required properties on the service for replay and load balancing. For
example, set:
–
FAILOVER_TYPE = TRANSACTION: For using Application Continuity
–
REPLAY_INITIATION_TIMEOUT = n: For setting the duration, in seconds,
to allow replay to start (where the value of n can be, for example, 60, 300, 900,
or 1800, depending on your needs)
–
FAILOVER_RETRIES = 30: For specifying the number of connection retries
for each replay
–
FAILOVER_DELAY = 10: For specifying the delay in seconds between
connection retries
–
GOAL = SERVICE_TIME: If you are using Oracle RAC or Oracle Global Data
Services, then this is a recommended setting
–
CLB_GOAL = SHORT: If you are using Oracle RAC or Oracle Global Data
Services, then this is a recommended setting
–
COMMIT_OUTCOME = TRUE: For using Transaction Guard
6-28 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
–
•
FAILOVER_RESTORE = LEVEL1: To automatically restore the states that are
preset on the connection pool before the application uses it—including
AUTOCOMMIT state (for Java and SQL*Plus), NLS states, and TAGS
(Module, action, client id, esid) states.
Grant permission on the Transaction Guard package, DBMS_APP_CONT, to the
database users that fail over using Application Continuity, as follows:
GRANT EXECUTE ON DBMS_APP_CONT TO user_name;
•
Do not use the default database service corresponding to the DB_NAME or
DB_UNIQUE_NAME. Also, do not use the database service for high availability,
because this service cannot be enabled and disabled, and cannot be relocated on
Oracle RAC or switched over to Oracle Data Guard. This service is reserved for
Oracle Enterprise Manager Cloud Control (Cloud Control) and for DBAs.
Establishing the Initial State Before Application Continuity Replays
Some applications set an initial state for the connection before allowing applications to
use the connection.
Application Continuity must establish this initial state before replay starts. For these
applications, FAILOVER_RESTORE restores common states listed here. If the states
that the application presets are not listed here, and the application needs initial states,
then an additional callback needs to be added.
Examples of states that can be preset include:
•
PL/SQL package state
•
NLS Setting
•
Optimizer setting
During a request, Application Continuity reestablishes the entire state for the request.
This pre-requisite is for the initial state before Application Continuity starts replaying.
A callback is not required if FAILOVER_RESTORE restores all required states, which is
the case for almost all applications.
For applications that set state only at the beginning of a request, or for stateful
applications that gain performance benefits from using connections with a preset state,
choose one of these options:
•
FAILOVER_RESTORE = LEVEL1
•
FAILOVER_RESTORE = NONE and No Callback
•
Connection Labeling
•
Connection Initialization Callback
FAILOVER_RESTORE = LEVEL1
Setting FAILOVER_RESTORE to LEVEL1 automatically restores common state initial
settings before replaying the request.
The states restored include the following:
•
NLS_CALENDAR
•
NLS_CURRENCY
Ensuring Application Continuity 6-29
Application Continuity Operation and Usage
•
NLS_DATE_FORMAT
•
NLS_DATE_LANGUAGE
•
NLS_DUAL_CURRENCY
•
NLS_ISO_CURRENCY
•
NLS_LANGUAGE
•
NLS_LENGTH_SEMANTICS
•
NLS_NCHAR_CONV_EXCP
•
NLS_NUMERIC_CHARACTER
•
NLS_SORT
•
NLS_TERRITORY
•
NLS_TIME_FORMAT
•
NLS_TIME_TZ_FORMAT
•
TIME_ZONE (OCI, ODP.NET 12201)
•
NLS_TIMESTAMP_FORMAT
•
NLS_TIMESTAMP_TZ_FORMAT
•
CURRENT_SCHEMA
•
MODULE
•
ACTION
•
CLIENT_ID
•
ECONTEXT_ID
•
ECONTEXT_SEQ
•
DB_OP
•
AUTOCOMMIT states (for Java and SQL*Plus)
•
CONTAINER (PDB) and SERVICE for OCI and ODP.NET
The following are not supported by the THIN driver, so are excluded from the autorestoration option:
•
NLS_COMP
•
CALL_COLLECT_TIME
•
CLIENT_INFO
FAILOVER_RESTORE = NONE and No Callback
In this scenario, the application does not assume any state when borrowing a
connection from a pool, or uses UCP or WebLogic labels to reestablish the initial state.
6-30 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Connection Labeling
Connection Labeling is a generic pool feature that is recommended for its excellent
performance. When Connection Labeling is present, Application Continuity uses it.
Since the Connection Labeling is recreating the state, FAILOVER_RESTORE can be set
to NONE.
This scenario is applicable to Universal Connection Pool (UCP) and Oracle WebLogic
server. The application can be modified to take advantage of the preset state on
connections. Connection Labeling APIs determine how well a connection matches, and
use a callback to populate the gap when a connection is borrowed.
Related Topics:
Oracle Universal Connection Pool Developer’s Guide
Connection Initialization Callback
In this scenario, the replaying driver (JDBC or OCI) uses an application callback to set
the initial state of the session during runtime and replay. The JDBC replay driver
provides a connection initialization callback interface and methods to register and
unregister connection initialization callbacks in the
oracle.jdbc.replay.OracleDataSource interface. For OCI and ODP.NET,
register the TAF callback.
When registered, the initialization callback is executed at each successful reconnection
following a recoverable error. An application is responsible for ensuring that the
initialization actions are the same as that on the original connection before failover. If
the callback invocation fails, then replay is disabled on that connection. Use the
connection initialization callback only when the application has not implemented UCP
and WebLogic Connection Labeling and the state cannot be restored automatically by
setting FAILOVER_RESTORE=LEVEL1.
Delaying the Reconnection in Application Continuity
By default, when Application Continuity initiates a failover, the driver attempts to
recover the in-flight work at an instance where the service is available.
For recovering the work, the driver must establish a good connection with the
instance. This reconnection can take some time if the database or the instance must be
restarted before the service is relocated and published. So, the failover must be
delayed until the service is available from another instance or database.
You must use the FAILOVER_RETRIES and FAILOVER_DELAY parameters to manage
connecting and reconnecting. These parameters can work well in conjunction with a
planned outage, for example, an outage that may make a service unavailable for
several minutes. While setting the FAILOVER_DELAY and FAILOVER_RETRIES
parameters, check the value of the REPLAY_INITIAITION_TIMEOUT parameter first.
The default value for this parameter is 900 seconds. A high value for the
FAILOVER_DELAY parameter can cause replay to be canceled.
Parameter Name
Possible Value
Default Value
FAILOVER_RETRIES
Positive integer zero or above
30
FAILOVER_DELAY
Time in seconds
3
The following examples show various failover scenarios:
Ensuring Application Continuity 6-31
Application Continuity Operation and Usage
•
Creating Services on Oracle RAC with Application Continuity
•
Modifying Services on Single-instance Databases to use Application Continuity
Creating Services on Oracle RAC with Application Continuity
You can create services on Oracle RAC that utilize Application Continuity.
If you are using Oracle RAC or Oracle RAC One Node, then use SRVCTL to create
services, as follows:
For policy-managed databases:
$ srvctl add service -db codedb -service GOLD -serverpool ora.Srvpool -clbgoal SHORT
-rlbgoal SERVICE_TIME
-failover_restore LEVEL1 -failoverretry 30 -failoverdelay 10 -commit_outcome TRUE failovertype TRANSACTION
-replay_init_time 1800 -retention 86400 -notification TRUE
For administrator-managed databases:
$ srvctl add service -db codedb -service GOLD -preferred serv1 -available serv2 clbgoal SHORT
-rlbgoal SERVICE_TIME -failover_restore LEVEL1 -failoverretry 30 -failoverdelay 10
-commit_outcome TRUE
-failovertype TRANSACTION -replay_init_time 1800 -retention 86400 -notification
TRUE
Modifying Services on Single-instance Databases to use Application Continuity
If you are using a single-instance database, then use the DBMS_SERVICE package to
modify services as follows:
DECLARE
params dbms_service.svc_parameter_array;
BEGIN
params('FAILOVER_TYPE'):='TRANSACTION';
params('REPLAY_INITIATION_TIMEOUT'):=1800;
params('RETENTION_TIMEOUT'):=86400;
params('FAILOVER_DELAY'):=10;
params('FAILOVER_RETRIES'):=30;
params('FAILOVER_RESTORE'):='LEVEL1';
params('commit_outcome'):='true';
params('aq_ha_notifications'):='true';
dbms_service.modify_service('[your service]',params);
END;
/
Using Application Continuity with SQL*Plus
Use the -ac flag for SQL*Plus applications.
The -ac flag uses the standard Dynamic mode for session state, and disables at
COMMIT. Static mode is available only for static applications.
•
Use the -ac flag, as follows:
sqlplus –ac user/[email protected]
Using Application Continuity for Planned Maintenance
For planned maintenance, the recommended approach is to drain requests from
Oracle connection pools in combination with Application Continuity for those
6-32 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
requests that do not complete. Instances do need to be stopped to switch over to the
patched software.
This has the least impact when there is minimal recovery to complete.
To use Application Continuity for planned maintenance:
1.
Use any FAN-aware pool, such as OCI, UCP, WebLogic Server, or ODP.NET
Managed and Unmanaged Drivers.
The FAN planned event drains at request boundaries.
Note: ODP.NET Managed Driver does not support Application Continuity.
2.
Use the srvctl relocate service command to relocate the service from the
instance without disrupting the sessions (do not use the -force parameter), or,
for a uniform service, use the srvctl stop service command on the instance
(again, do not use the -force parameter).
•
For Oracle RAC One Node, use the srvctl relocate database
command with the -force parameter.
The FAN planned event clears the idle sessions immediately and marks the active
sessions to be released at check-in (end of request). This drains the sessions from
the instance without disrupting work.
3.
If not all sessions have checked in and the time to stop the instance has been
reached, then stop the instance (abort).
For Application Continuity-enabled pools (UCP, WebLogic, Tuxedo, ODP.NET,
and OCI), and any Java pool that adds beginRequest/endRequest ,
Application Continuity attempts to recover those remaining sessions.
4.
Restart the instance and service.
Runtime load balancing, when enabled, balances the sessions back to the restored
instance at the next request boundaries.
Running Without Application Continuity
Sometimes Application Continuity is not in effect, through deliberate choice, error, or
oversight.
Application Continuity is not in effect when it has not been started or when it has been
disabled. If it has been disabled, it remains so through to the endRequest call.
Application Continuity is not started when the service property FAILOVER_TYPE
does not have the value set to TRANSACTION. For planned maintenance, set the
FAILOVER_TYPE value to TRANSACTION, beforehand; the setting applies to new
connections, and existing connections retain their original service value.
Application Continuity is disabled for the current request when any of the following
occurs:
•
The application runs a statement that is restricted for Application Continuity (for
example, ALTER SYSTEM).
•
Application Continuity is explicitly disabled using disableReplay.
•
A COMMIT statement is issued when the service parameter
session_state_consistency is set to Dynamic (the default).
Ensuring Application Continuity 6-33
Application Continuity Operation and Usage
•
An endRequest statement is issued until the next beginRequest is issued.
•
The session is terminated or disconnected and the NOREPLAY keyword is
specified.
Related Topics:
Disabling Replay in Application Continuity
By default, replay occurs following a recoverable error.
Terminating or Disconnecting a Session Without Replay
Disabling Replay in Application Continuity
By default, replay occurs following a recoverable error.
If the application has requests that the application does not want repeated, the
application can take a connection to a service that does not have Application
Continuity enabled, or can explicitly call an API to disable replay for those requests.
For example, if the application uses UTL_SMTP and does not want messages repeated,
use a connection to a different service, or use the disableReplay API on Java, or
OCIRequestDisableReplay API for OCI. All other requests continue to be
replayed.
For applications with external actions (for example, autonomous transactions or using
UTL_HTTP to issue an SOA call), Application Continuity remains transparent if the
application's correctness is preserved when these external actions are replayed after a
failure.
The following rules are generic. They apply to all applications that replay work,
including Application Continuity, and TAF (release 12.2 and after).
•
Application Calls Autonomous Transactions, External PL/SQL, or Java Actions
that Should Not Be Repeated
•
Application Synchronizes Independent Sessions
•
Application Uses Time at the Middle Tier in the Execution Logic
•
Application Assumes that ROWIds Do Not Change
•
Application Assumes that Location Values Do Not Change
Related Topics:
Potential Side Effects of Application Continuity
When a session is rebuilt, all states are rebuilt, including rerunning
statements that leave side effects.
Restrictions and Other Considerations for Application Continuity
Be aware of these restrictions and considerations when using
Application Continuity.
Application Calls Autonomous Transactions, External PL/SQL, or Java Actions that Should Not Be
Repeated
Autonomous transactions, external PL/SQL calls, and Java callouts can have side
effects that are separate from the main transaction, and these side effects are replayed
unless you specify otherwise.
6-34 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Examples of side effects separate from the main transaction include writing to an
external table, sending email, forking sessions out of PL/SQL (including calls to
UTL_HTTP, UTL_URL, UTL_FILE, UTL_FILE_TRANSFER, UTL_SMPT, UTL_TCP,
UTL_MAIL, DBMS_PIPE, or DBMS_ALERT) or Java (including executing a shell script
in the form Process proc = rt.exec(command);), transferring files, and accessing external
URLs. Actions such as these leave persistent side effects. PL/SQL messaging and Java
callouts can leave persistent results behind. For example, if a user walks away part
way through some work without committing and the session times out or the user
issues Ctrl+C, the foreground or a component fails; the main transaction rolls back
while the side effects may have been applied. (For more information about side effects,
see Potential Side Effects of Application Continuity.)
Application developers decide whether to allow replay for external actions. Examples
include using UTL_HTTP to issue an SOA call, or UTL_SMTP to send a message, or
UTL_URL to access a website. If such external actions must not be replayed, use a
connection without AC, or use one of the disable Replay APIs.
Application Synchronizes Independent Sessions
You must not configure an application for replay if the application synchronizes
independent sessions using volatile entities that are held until COMMIT, ROLLBACK, or
session loss. For example, the application might synchronize multiple sessions
connected to several data sources that are otherwise inter-dependent using resources
such as a database lock. This synchronization may be acceptable if the application is
only serializing these sessions and understands that any session may fail. However, if
the application assumes that a lock or any other volatile resource held by one data
source implies exclusive access to data on the same or a separate data source from
other connections, then this assumption may be invalidated when replaying.
During replay, the client driver is not aware that the sessions are dependent on one
session holding a lock or other volatile resource. You can also use pipes, buffered
queues, stored procedures taking a resource (such as a semaphore, device, or socket)
to implement the synchronization that are lost by failures.
Application Uses Time at the Middle Tier in the Execution Logic
You must not configure an application for replay if the application uses the wall clock
at the middle tier as part of the execution logic. The client driver does not repeat the
middle-tier time logic, but uses the database calls that execute as part of this logic. For
example, an application using middle-tier time might assume that a statement
executed at Time T1 is not reexecuted at Time T2, unless the application explicitly does
so.
Application Assumes that ROWIds Do Not Change
If an application caches ROWIDs, then access to these ROWIDs might be invalidated
due to database changes. Although a ROWID uniquely identifies a row in a table, a
ROWID might change its value in the following situations:
•
The underlying table is reorganized.
•
An index is created on the table.
•
The underlying table is partitioned.
•
The underlying table is migrated.
•
The underlying table is exported and imported using EXP/IMP/DUL.
Ensuring Application Continuity 6-35
Application Continuity Operation and Usage
•
The underlying table is rebuilt using Golden Gate or Logical Standby or other
replication technology.
•
The database of the underlying table is flashed back or restored.
Oracle does not recommend, in general, that an application store ROWIDs for later use
because the corresponding row might either not exist or contain completely different
data. Note that ROWIDs do not prevent using Application Continuity. Replays can be
rejected.
Application Assumes that Location Values Do Not Change
SYSCONTEXT options comprise a location-independent set such as National Language
Support (NLS) settings, ISDBA, CLIENT_IDENTIFIER, MODULE, and ACTION, and a
location-dependent set that uses physical locators. Typically, an application does not
use the physical identifiers, except in testing environments. If physical locators are
used in mainline code, then the replay finds the mismatch and rejects it. However, it is
acceptable to use physical locators between requests (before beginRequest) or in
callbacks. A common issue is for QA to modify test applications to select V
$INSTANCE. As V$INSTANCE can change, only put this check in the callback or select
the instance locally at the client and not from the database.
Example
select
sys_context('USERENV','DB_NAME')
,sys_context('USERENV','HOST')
,sys_context('USERENV','INSTANCE')
,sys_context('USERENV','IP_ADDRESS')
,sys_context('USERENV','ISDBA')
,sys_context('USERENV','SESSIONID')
,sys_context('USERENV','TERMINAL')
,sys_context('USERENV','SID')
from dual;
Terminating or Disconnecting a Session Without Replay
If Application Continuity is configured and if a DBA terminates or disconnects a
session by using the ALTER SYSTEM KILL SESSION or ALTER SYSTEM
DISCONNECT SESSION statement, then Application Continuity, by default attempts,
to recover the session. However, if you do not want the session to be replayed, then use
the NOREPLAY keyword, as follows:
alter system kill session 'sid, serial#, @inst' noreplay;
alter system disconnect session 'sid, serial#, @inst' noreplay
$ srvctl stop service -db orcl -instance orcl2 –drain_timeout 60 -stopoption
immediate -force -noreplay
$ srvctl stop service -db orcl -node myode3 –noreplay -drain_timeout 60 -stopoption
immediate -force
$ srvctl stop instance -node mynode3 -drain_timeout 60 -stopoption immediate -force –
noreplay
To terminate all sessions running on the local instance (rather that only one session)
and not have the sessions replayed, you can also use the
6-36 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
DBMS_SERVICE.DISCONNECT_SESSION PL/SQL procedure and specify NOREPLAY
for the disconnect_option parameter.
Related Topics:
Oracle Database SQL Language Reference
Oracle Database PL/SQL Packages and Types Reference
Mutable Functions and Application Continuity
When a request is replayed, the default and desired treatment of mutable objects can
vary.
A mutable function is a nondeterministic function that can obtain a new value every
time it is called. An example of a mutable function is a call to the SYSTIMESTAMP
function. Client applications using Application Continuity can determine whether to
keep the original value for mutable functions if the request is replayed.
Support for keeping mutable fucntion values is currently provided for SYSDATE,
SYSTIMESTAMP, SYS_GUID, and sequence.NEXTVAL. If the original values are not
kept and if different values for these mutable objects are returned to the client, then
replay is rejected because the client observes different results. If the application can
use original values, then configure mutable functions using the KEEP clause for owned
sequences and GRANT KEEP for other users. (Most applications need sequence values
to be kept at replay, for bind variable consistency.)
Note:
Keeping SYS_GUID values is supported only for serial execution plans. When
parallel query is used, Application Continuity is not able to restore original
values for SYS_GUID.
Table 6-4 shows examples of the treatment of mutable functions by products during
replay. (Actual implementation depends on specific products and releases.)
Table 6-4
Example Treatment of Mutable Objects by Products During Replay
Mutable Function
Product 1
Product 2
Product 3
SYSDATE, SYSTIMESTAMP
Original
Original
Current
Sequence NEXTVAL and
CURRVAL
Original
Original
(Not applicable)
SYS_GUID
Original
(Not applicable)
(Not applicable)
To allow Application Continuity to keep and use original function results at replay:
•
The database user running the application might have the KEEP DATE TIME and
KEEP SYSGUID privileges granted, and the KEEP SEQUENCE object privilege on
each sequence whose value is to be kept. For example:
grant KEEP DATE TIME to user2;
grant KEEP SYSGUID to user2;
grant KEEP SEQUENCE on sales.seq1 to user2;
Ensuring Application Continuity 6-37
Application Continuity Operation and Usage
Notes:
•
–
GRANT ALL ON object does not include (that is, does not grant the
access provided by) the KEEP DATE TIME and KEEP SYSGUID
privileges, and the KEEP SEQUENCE object privilege.
–
Grant privileges related to mutable function support only to application
users, and to each application user grant only the necessary privileges.
–
Do not grant DBA privileges to database users running applications for
which you want replay to be enabled.
Sequences in the application can use the KEEP attribute, which keeps the original
values of sequence.NEXTVAL for the sequence owner, so that the keys match
during replay. Most applications need sequence values to be kept at replay. The
following example sets the KEEP attribute for a sequence (in this case, one owned
by the user executing the statement; for others, use GRANT KEEP SEQUENCE):
SQL> CREATE SEQUENCE my_seq KEEP;
SQL> -- Or, if the sequence already exists but without KEEP:
SQL> ALTER SEQUENCE my_seq KEEP;
Note:
Specifying ALTER SEQUENCE ... KEEP/NOKEEP applies to the owner of the
sequence. It does not affect other users (not the owner) that have the KEEP
SEQUENCE object privileges. If you want NOKEEP for all users, then be sure not
to grant the KEEP SEQUENCE object privilege to these users (or to revoke it
from each user if the privilege has been granted).
•
To keep function results (for named functions) at replay, the DBA must grant
KEEP privileges to the user invoking the function. This security restriction ensures
that it is valid for replay to save and restore function results for code that is not
owned by that user.
The following additional considerations apply to granting privileges on mutable
functions:
•
If a user has the KEEP privilege granted on mutable function values, then the
objects inherit mutable access when the SYS_GUID, SYSDATE, and
SYSTIMESTAMP functions are called.
•
If the KEEP privilege is revoked on mutable values on a sequence object, then SQL
or PL/SQL blocks using that object do not allow mutable collection or application
for that sequence.
•
If granted privileges are revoked between runtime and failover, then the mutable
values that are collected are not applied for replay.
•
If new privileges are granted between runtime and failover, then mutable values
are not collected and these values are not applied for replay.
Related Topics:
Oracle Database SQL Language Reference
6-38 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Oracle Database SQL Language Reference
Administering Mutable Values
To keep function results at replay, you must grant KEEP privileges to the user
invoking the function.
Grant and Revoke Interface
To grant and revoke permission to keep mutables for Oracle Dates and SYS_GUID:
GRANT [KEEP DATE_TIME | KEEP SYS_GUID]...[to USER]
REVOKE [KEEP DATE_TIME | KEEP SYS_GUID]...[from USER]
For example, for possible Oracle E-Business Suite usage with original dates:
GRANT KEEP DATE_TIME, KEEP SYS_GUID to [custom user];
GRANT KEEP DATE_TIME, KEEP SYS_GUID to [apps user];
Granting Permission to Keep Mutables for Oracle Sequences
To grant permission to the owner of the sequence:
CREATE SEQUENCE [sequence object] [KEEP|NOKEEP];
ALTER SEQUENCE [sequence object] [KEEP|NOKEEP];
The preceding commands keep the original values of sequence.nextval for
replaying so that keys match.
To grant and revoke permission for others using the sequence:
GRANT KEEP SEQUENCES...[to USER] on [sequence object];
REVOKE KEEP SEQUENCES...[from USER] on [sequence object];
For example, for possible Oracle E-Business Suite usage with original sequence values:
GRANT KEEP SEQUENCES to [apps user] on [sequence object];
GRANT KEEP SEQUENCES to [custom user] on [sequence object];
Rules for Grants on Mutables
•
If you grant all on an object for a user, then mutables are excluded. Mutables
require explicit grants. Oracle does not support granting mutables to the users
supplied or created by Oracle Database, such as SYS, AUDSYS, GSMUSER, and
SYSTEM.
•
The DBA role includes mutable permission.
•
If a user has mutables granted, then the objects inherit mutable access when the
mutable functions are called (in SYS_GUID, SYSDATE and SYSTIMESTAMP).
•
If keeping mutables on a sequence object is revoked, then SQL or PL/SQL
commands using that object does not allow mutable collection or application for
that sequence.
•
If grants are revoked between run time and failover, then the mutables that were
collected are not applied.
•
If grants are granted between run time and failover, then mutables are not
collected and so none are applied.
Ensuring Application Continuity 6-39
Application Continuity Operation and Usage
Session State Consistency
Session state consistency describes how non-transactional state is changed during a
request.
Examples of session state are NLS settings, optimizer preferences, event settings,
PL/SQL global variables, temporary tables, advanced queues, LOBs, and result cache.
If non-transactional values change in committed transactions, then use the default
value, Dynamic (session_state_consistency is a service level attribute, the
default value of which is Dynamic).
Using Dynamic mode, after a COMMIT has executed, if the state was changed in that
transaction, then it is not possible to replay the transaction to reestablish that state if
the session is lost. Applications can be categorized depending on whether the session
state after the initial setup is static or dynamic, and hence whether it is correct to
continue past a COMMIT operation.
Dynamic mode is appropriate for almost all applications. If you are unsure, then use
Dynamic mode. If your customers or users can modify your application, then you
must use Dynamic mode.
This section includes the following topics:
•
Dynamic Session State Consistency
•
Static Session State Consistency
Dynamic Session State Consistency
A session has dynamic state if the session state values are not fully restored by
FAILOVER_RESTORE, or by adding the initialization callback.
Once the first transaction completes, failover is internally disabled until the next
request starts. In Dynamic session state consistency mode, state changes occur during
the request and replay is enabled at the beginning of the next request.
Set the session state consistency mode to Dynamic if the nontransactional session state
changes while transactions are executing. Examples of nontransactional session state
that can change at runtime are ALTER SESSION, PL/SQL global variables,
SYS_CONTEXT, and temporary table contents. If the application changes
nontransactional state inside transactions and commits, this state cannot be replayed
and the state setting must be Dynamic. When using Dynamic mode for Application
Continuity, replay is disabled at COMMIT until the next request begins. Dynamic is the
default value.
The nontransactional session state (NTSS) changes during a request when the session
state consistency mode is Dynamic.
Replay (that is, Application Continuity) is enabled at the beginRequest call, and is
disabled on a COMMIT , an endRequest call, or a restricted call. Following is the step
logic for three application scenarios:
•
No transaction
•
A transaction with COMMIT as the last statement
•
A transaction with an embedded COMMIT statement
For the request with no transaction, the logical steps are as follows:
6-40 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
Other actions.
5.
Check in.
6.
End request and disable replay.
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
For the request with a transaction with COMMIT as the last statement, the logical
steps are as follows:
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
The transaction begins.
5.
Other actions.
6.
Commit (which disables replay).
7.
Check in.
8.
End request.
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
For the request with a transaction with an embedded COMMIT statement, the
logical steps are as follows:
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
The transaction begins.
5.
Other actions.
6.
Commit (which disables replay).
7.
Other actions, during which Application Continuity is not covering the
application.
8.
Check in.
9.
End request.
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
Ensuring Application Continuity 6-41
Application Continuity Operation and Usage
Static Session State Consistency
Static mode is used for long running stateless applications. Do not use Static
mode for applications that are not stateless.
Set the session state consistency mode to Static, only if all non-transactional state
changes, such as NLS settings, SYS_CONTEXT, PL/SQL variables, and optimizer
preferences, are set as part of the initialization once per request, and if this session
state does not change during transactions. The settings can be established once per
connection at connection establishment when using FAILOVER_RESTORE=LEVEL1, a
callback, or labels, for example, or at each checkout from a pool.
When using Static mode for Application Continuity, transactional failover
continues beyond the first transaction of a request. This is useful for applications that
set beginRequest once and run long processing operations such as batch jobs, and
long reports.
Static mode is not supported for applications that use calls that change nontransactional state in transactions. Specific examples of such calls include:
•
PL/SQL subprograms
•
SYS_CONTEXT
•
ALTER SESSION
Specify static mode with caution. Use static mode only when the application does not
change the non-transactional session state inside transactions. Declaring the session
state consistency mode as Static indicates that it is safe to continue beyond the first
COMMIT in a request. Dynamic mode is appropriate for most applications. Do not use
static mode if users or customers can modify or customize the application.
The non-transactional session state remaining constant (that is, not changing) during a
request when the session state consistency mode is Static.
Replay (that is, Application Continuity) is enabled at the beginRequest call, and is
disabled on a restricted call, on a disableReplay or OCIRequestDisableReplay
call, or on an endRequest call.
Following is the step logic for three application scenarios:
•
No transaction
•
One or more transactions each ending with COMMIT as the last statement
•
A transaction with a COMMIT statement followed by a transaction with a restricted
call that disables Application Continuity
For the request with no transaction, the logical steps are as follows:
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
Other actions.
5.
Check in.
6.
End request and disable replay.
6-42 Oracle Real Application Clusters Administration and Deployment Guide
Application Continuity Operation and Usage
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
For the request with one or more transactions (each with COMMIT as the last
statement), the logical steps are as follows:
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
The transaction begins.
5.
The transaction commits.
6.
The transaction is purged.
(For each additional transaction, steps 4 through 6 occur.)
7.
Other actions.
8.
Check in.
9.
End request.
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
For the request with a transaction with a COMMIT followed by a transaction with a
restricted call, the logical steps are as follows:
1.
Check out.
2.
Begin request and enable replay.
3.
Issue one or more SELECT statements and perhaps other PL/SQL statements.
4.
The transaction begins.
5.
The transaction commits.
6.
The transaction is purged.
7.
The second transaction begins.
8.
The transaction makes a restricted call, which causes Application Continuity to be
disabled.
9.
The transaction is purged.
10. Other actions
11. Check in.
12. End request.
Replay is disabled at endRequest, at a restricted call, and for an explicit
disableReplay or OCIRequestDisableReplay call.
Ensuring Application Continuity 6-43
Potential Side Effects of Application Continuity
Related Topics:
FAILOVER_RESTORE = LEVEL1
Setting FAILOVER_RESTORE to LEVEL1 automatically restores common
state initial settings before replaying the request.
Potential Side Effects of Application Continuity
When a session is rebuilt, all states are rebuilt, including rerunning statements that
leave side effects.
These side effects might be exactly what is required, such as writing a report or
completing some auditing.
Application Continuity replays PL/SQL chronologically to restore database state. This
serves to rebuild the session as if the user submission was delayed. Most applications
want the full state rebuilt as if the submission was repeated, such as writing a report
or completing some auditing. However, the actions that are replayed to build the state
might include some for which you want to take action to accommodate or mitigate the
effects of the replay. Some applications elect to disable replay for requests that contain
calls that they do not want to repeat.
Examples of actions that create side effects include the following:
•
Autonomous transactions (independent transactions that can be called from other
transactions)
•
DBMS_ALERT calls (email or other notifications)
•
DBMS_FILE_TRANSFER calls (copying files)
•
DBMS_PIPE and RPC calls (to external sources)
•
UTL_FILE calls (writing text files)
•
UTL_HTTP calls (making HTTP callouts)
•
UTL_MAIL calls (sending email)
•
UTL_SMTP calls (sending SMTP messages)
•
UTL_TCP calls (sending TCP messages)
•
UTL_URL calls (accessing URLs)
Related Topics:
Disabling Replay in Application Continuity
By default, replay occurs following a recoverable error.
Restrictions and Other Considerations for Application Continuity
Be aware of these restrictions and considerations when using Application Continuity.
•
Application Continuity excludes :
–
JDBC OCI driver (type 2)
–
ODP.NET, Managed Driver
–
OLE DB
6-44 Oracle Real Application Clusters Administration and Deployment Guide
Restrictions and Other Considerations for Application Continuity
–
ODBC
•
For applications using JDBC, there is no support for oracle.sql deprecated
concrete classes: BLOB, CLOB, BFILE, OPAQUE, ARRAY, STRUCT, or ORADATA.
•
For streams arguments, replay is on a "best effort" basis. For example, if the
application is using physical addresses, the address has gone with the outage and
cannot be repositioned. JDBC stream setters (such as setBinaryStream), for
example, cause replay to be disabled.
•
The replay target database must be in the same database cluster (Oracle RAC,
Oracle Data Guard, Oracle Active Data Guard, or Oracle Multitenant) as the
source database.
To protect the integrity of business transactions, Application Continuity does not
replay if the target is a different database or if it is the same database or same
pluggable database but with data loss, such as one flashed back, recovered
incompletely by media recovery, or opened by Oracle Data Guard earlier in time.
•
For OCI and ODP.NET, in Oracle Database 12c release 2 (12.2.0.1), Application
Continuity on OCI driver excludes ADTs, advance queues, dynamic binds, and
some LOB APIs. These exclusions do not apply to Java.
•
If a statement cache at the application server level is enabled (for example, the
WebLogic or third-party application server statement cache), this must be
disabled when the replay is used. Instead, configure the JDBC statement cache,
which performs better because it is optimized for JDBC and Oracle and because it
supports Application Continuity. Use
oracle.jdbc.implicitstatementcachesize=nnn.
•
Starting with Oracle Database 12 release 2 (12.2), replay is supported for the XA
data source for Java and ODP.NET, Unmanaged Driver. Replay supports local
transactions. Replay silently disables when two-phase is used. This enables
Application Continuity to work very well with promotable XA and with
applications using the XA data source and mostly not using XA.
•
Replay is disabled if a request issues an ALTER SYSTEM or ALTER DATABASE
statement.
•
Replay is disabled at a request level for ALTER SESSION statements that are
deemed unsafe to rebuild the session. These include statements for setting
support-level events, and disabling and enabling COMMIT IN PROCEDURE and
GUARD.
However, ALTER SESSION statements at an application level are supported for
replay. These include statements for globalization support (NLS) settings, stored
and private outlines, setting the container (CDB/PDB), SQL trace, and PL/SQL
warnings.
•
Replay is not supported if you are using Oracle Active Data Guard with read/
write database links back to the primary database. This is a security restriction
from Transaction Guard.
•
Replay does not apply for failure of a parallel query call when this is a statementlevel failure. For example, replay would not occur after an
ORA-12805:parallel query server died unexpectedly error for a call
failure encountered during an instance or node failure or memory issue.
Ensuring Application Continuity 6-45
Transaction Guard for Improving Client Failover
•
For Java only, replay does not support DRCP. Dedicated and Shared Servers are
supported.
•
The request uses 2PC XA. Starting with Oracle Database 12c release 2 (12.2),
Application Continuity is supported for promotable XA and using XA data
sources, while XA is not in use.
Note:
If you are creating clones of databases by splitting disk images (for example,
BCVs) or by cloning so it is a "different" database to make a logical standby or
logical copy that is not a physical or Oracle Active Data Guard database, then
nid must be used to change the DBID to differentiate the databases. For
information about nid program usage, see these My Oracle Support notes:
How to Change the DBID and the DBNAME by using NID (Doc Id 224266.1) and
Changing DBNAME and DBID of Oracle RAC Database Using NID (Doc Id
464922.1).
Related Topics:
Oracle Call Interface Programmer's Guide
Transaction Guard for Improving Client Failover
Transaction Guard prevents a transaction being replayed by Application Continuity
from being applied more than once.
Failing to recognize that the last submission has committed, or that it shall commit
sometime soon, or that the last submission has not run to completion, is a problem for
applications. It can cause users who resubmit or applications that use their own replay
to issue duplicate requests, repeating changes that are already committed to the
database, and other forms of logical corruption. Transaction Guard can be used to
solve this problem.
Application Continuity automatically enables and uses Transaction Guard, but you
can also enable Transaction Guard independently. If the application has implemented
an application-level replay, then it requires the application to be integrated with
Transaction Guard to provide idempotence.
In Oracle Database 12c, Transaction Guard provides a new, fully integrated tool for
applications to use to achieve idempotence automatically and transparently, and in a
manner that scales. Transaction Guard uses Logical Transaction ID (LTXID) to avoid
submitting duplicate transactions. This is referred to as transaction idempotence. The
LTXID persists on commit and is reused following a rollback. During normal runtime,
a LTXID is automatically held in the session at both the client and server for each
database transaction. At commit, the LTXID is persisted as part of committing the
transaction and the next LTXID to use is returned to the client.
Transaction Guard for XA Transactions
Transaction Guard also supports XA-based transactions, which are transactions that
are an option for transaction managers, such as Oracle WebLogic Server, Oracle
Tuxedo, and MicroSoft Transaction Server (exposed to Oracle Database through
Oracle ODP.NET).
Transaction Guard support for XA transactions provides safe replay following
recoverable outages for XA transactions on Oracle WebLogic Server. With the addition
6-46 Oracle Real Application Clusters Administration and Deployment Guide
Transaction Guard for Improving Client Failover
of XA support, Oracle WebLogic Server can provide replay with idempotence
enforced using Transaction Guard.
This section includes the following topics:
•
Transaction Guard Configuration Checklist
•
Configuring Services for Transaction Guard
•
Failing Over OCI Clients with TAF
Related Topics:
Oracle Database Development Guide
Oracle Database Development Guide
Oracle Database JDBC Developer’s Guide
Transaction Guard Configuration Checklist
Before configuring services for Transaction Guard, use the following configuration
checklist:
•
Grant permission to the application user who will call GET_LTXID_OUTCOME, as
follows:
GRANT EXECUTE ON DBMS_APP_CONT to user_name;
•
Locate and define the transaction history table for optimal performance.
The transaction history table (LTXID_HIST) is created, by default, in the SYSAUX
tablespace when you create or upgrade an Oracle Database. New partitions are
added when you add instances, using the storage of the last partition. If the
location of transaction history table is not optimal for performance, then you can
move it to another tablespace and create partitions there. For example, the
following statement moves the transaction history table to a tablespace named
FastPace:
ALTER TABLE LTXID_TRANS move partition LTXID_TRANS_1 tablespace FastPace
storage ( initial 10G next 10G minextents 1 maxextents 121 );
•
Set values for the -commit_outcome and -retention_timeout service
parameters.
•
If you are using Oracle RAC, Oracle Data Guard, or Oracle Active Data Guard,
then Oracle recommends that you use FAN for fast notification of an outage.
Configuring Services for Transaction Guard
To configure services to use Transaction Guard, set the following service parameters:
•
-commit_outcome: Set the -commit_outcome service parameter to TRUE. This
service parameter determines whether the transaction commit outcome is
accessible after the COMMIT has executed and an outage has occurred. While
Oracle Database has always made COMMIT durable, Transaction Guard makes
the outcome of the COMMIT durable, and is used by applications to enforce the
status of the last transaction executed before an outage.
Ensuring Application Continuity 6-47
Failing Over OCI Clients with TAF
•
-retention: Use the -retention service parameter with -commit_outcome.
This service parameter determines the amount of time, in seconds, that the
COMMIT outcome is retained. Oracle recommends that most installations use the
default value.
The following SRVCTL command configures a policy-managed service named sales
for Transaction Guard:
$ srvctl add service -db crm -service sales -serverpool spool_1
-commit_outcome TRUE -retention 86400 -notification TRUE
The following SRVCTL command configures an administrator-managed service
named sales for Transaction Guard:
$ srvctl add service -db crm -service sales -preferred crm_1,crm_2
-available crm_3,crm_4 -commit_outcome TRUE -retention 86400
-notification TRUE
You can also modify an existing service to configure it for Transaction Guard by using
the srvctl modify service command.
Note:
Do not use the default database service, the service which has the name set to
the value of db_name or db_unique_name. The default service is used for
administrative purposes and does not have the same properties as usercreated services.
Related Topics:
srvctl add service
Adds services to a database and assigns them to instances.
srvctl modify service
Modifies service configuration.
About Application Continuity
Application Continuity masks many recoverable database outages
(when replay is successful) from applications and users by restoring the
database session: the full session, including all states, cursors, variables,
and the last transaction if there is one.
Oracle Database JDBC Developer’s Guide
Oracle Call Interface Programmer's Guide
Failing Over OCI Clients with TAF
When Oracle Net Services establishes a connection to an instance, the connection
remains open until the client closes the connection, the instance is shutdown, or a
failure occurs.
If you configure transparent application failover (TAF) for the connection, then Oracle
Database replays the session at a surviving instance when an outage occurs.
TAF can restart a query after failover has completed but for other types of
transactions, such as INSERT, UPDATE, or DELETE, the application must rollback the
failed transaction and resubmit the transaction. You must also reexecute any session
customizations, in other words, ALTER SESSION statements, after failover has
6-48 Oracle Real Application Clusters Administration and Deployment Guide
Failing Over OCI Clients with TAF
occurred. However, with TAF, a connection is not moved during normal processing,
even if the workload changes over time.
Services simplify the deployment of TAF. You can define a TAF policy for a service,
and all connections using this service will automatically have TAF enabled. This does
not require any client-side changes. The TAF setting on a service overrides any TAF
setting in the client connection definition.
You can define a TAF policy for all users of a service by defining the failovermethod and -failovertype parameters. You can further define the TAF
policy by setting the number of times that a failed session attempts to reconnect to the
service and how long it should wait between reconnection attempts using the failoverretry and -failoverdelay parameters, respectively.
To define a TAF policy for a service, use SRVCTL as in the following example, where
the service name is tafconn.example.com and the database name is CRM:
$ srvctl modify service -db crm -service tafconn.example.com -failovermethod BASIC
-failovertype SELECT -failoverretry 10 -failoverdelay 30
OCI applications with TAF enabled should use FAN high availability events for fast
connection failover.
TAF Supports Transaction Guard and FAILOVER_RESTORE
When you are using Transaction Guard, TAF manages the errors for the developers.
When you use both TAF and Transaction Guard, developers can use the TAF errors to
roll back and safely resubmit or return uncommitted transactions (for TAF error codes
ORA-25402, ORA-25408, ORA-25405).
When you are using FAILOVER_RESTORE, TAF automatically restores common states,
which avoids the need for a callback for most applications.
Related Topics:
FAILOVER_RESTORE = LEVEL1
Setting FAILOVER_RESTORE to LEVEL1 automatically restores common
state initial settings before replaying the request.
Ensuring Application Continuity 6-49
Failing Over OCI Clients with TAF
6-50 Administration and Deployment Guide
7
Configuring Recovery Manager and
Archiving
This chapter explains how to configure Recovery Manager (RMAN) for use in Oracle
Real Application Clusters (Oracle RAC) environments. This chapter also provides
procedures for using for archiving in Oracle RAC environments and discusses online
redo log and archived redo log considerations.
The topics in this chapter include:
•
Overview of Configuring RMAN for Oracle RAC
•
Archiving Mode in Oracle RAC
•
Configuring the RMAN Snapshot Control File Location
•
Configuring RMAN to Automatically Backup the Control File and SPFILE
•
Crosschecking on Multiple Oracle RAC Nodes
•
Configuring Channels for RMAN in Oracle RAC
•
Managing Archived Redo Logs Using RMAN in Oracle RAC
•
Archived Redo Log File Conventions in Oracle RAC
•
RMAN Archiving Configuration Scenarios
•
Monitoring the Archiver Processes
Overview of Configuring RMAN for Oracle RAC
RMAN enables you to back up, restore, and recover data files, control files, server
parameter files (SPFILEs) and archived redo log files. RMAN is included with Oracle
Database and does not require separate installation. You can run RMAN from the
command line or use RMAN in the Backup Manager in Oracle Enterprise Manager.
Archiving Mode in Oracle RAC
In order for redo log files to be archived, the Oracle RAC database must be in
ARCHIVELOG mode.
You can run the ALTER DATABASE SQL statement to change the archiving mode in
Oracle RAC, because the database is mounted by the local instance but not open in
any instances. You do not need to modify parameter settings to run this statement.
Configuring Recovery Manager and Archiving 7-1
Configuring the RMAN Snapshot Control File Location
Note:
•
The ARCHIVELOG mode is set at the database level, not the instance level.
Either all instances archive or none do.
•
You can also change the archive log mode by using the Recovery Settings
page in the Maintenance tab of the Oracle Enterprise Manager Oracle
RAC Database Home Page.
Related Topics:
Oracle Database Administrator’s Guide
Configuring the RMAN Snapshot Control File Location
The snapshot control file is a copy of a database control file created in an operating
system-specific location by RMAN.
RMAN creates the snapshot control file so that it has a consistent version of a control
file to use when either resynchronizing the recovery catalog or backing up the control
file.
You can specify a cluster file system or a raw device destination for the location of
your snapshot control file. This file is shared across all nodes in the cluster and must
be accessible by all nodes in the cluster. Run the following RMAN command to
determine the configured location of the snapshot control file:
SHOW SNAPSHOT CONTROLFILE NAME;
You can change the configured location of the snapshot control file. For example, on
Linux and UNIX systems you can specify the snapshot control file location as
$ORACLE_HOME/dbs/scf/snap_prod.cf by entering the following at the RMAN
prompt:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '$ORACLE_HOME/dbs/scf/snap_prod.cf';
This command sets the configuration for the location of the snapshot control file for
every instance of your cluster database. Therefore, ensure that the
$ORACLE_HOME/dbs/scf directory is shared by all nodes that perform backups.
The CONFIGURE command creates persistent settings across RMAN sessions.
Therefore, you do not need to run this command again unless you want to change the
location of the snapshot control file.
To delete a snapshot control file you must first change the snapshot control file
location, then delete the file at the older location, as follows:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO 'new_name';
DELETE COPY OF CONTROLFILE;
Related Topics:
Oracle Database Backup and Recovery Reference
Configuring RMAN to Automatically Backup the Control File and SPFILE
If you set CONFIGURE CONTROLFILE AUTOBACKUP to ON, then RMAN automatically
creates a control file and an SPFILE backup after you run the BACKUP or COPY
commands.
7-2 Oracle Real Application Clusters Administration and Deployment Guide
Crosschecking on Multiple Oracle RAC Nodes
RMAN can also automatically restore an SPFILE, if this is required to start an instance
to perform recovery, because the default location for the SPFILE must be available to
all nodes in your Oracle RAC database.
Note:
If you back up the control file using the SQL*Plus ALTER DATABASE
command, then you must also create the control file backup on a device
shared by all nodes.
These features are important in disaster recovery because RMAN can restore the
control file even without a recovery catalog. RMAN can restore an autobackup of the
control file even after the loss of both the recovery catalog and the current control file.
You can change the default name that RMAN gives to this file with the CONFIGURE
CONTROLFILE AUTOBACKUP FORMAT command. Note that if you specify an absolute
path name in this command, then this path must exist identically on all nodes that
participate in backups.
RMAN performs the control file autobackup on the first allocated channel. Therefore,
when you allocate multiple channels with different parameters, especially when you
allocate a channel with the CONNECT command, determine which channel will
perform the control file autobackup. Always allocate the channel for this node first.
Besides using the RMAN control file, you can also use Oracle Enterprise Manager to
use the RMAN features.
Related Topics:
Oracle Database Backup and Recovery User’s Guide
Crosschecking on Multiple Oracle RAC Nodes
When crosschecking on multiple nodes (and when operating RMAN in general),
configure the cluster so that all backups can be accessed by every node, regardless of
which node created the backup.
When the cluster is configured this way, you can allocate channels to any node in the
cluster during restore or crosscheck operations.
If you cannot configure the cluster so that each node can access all backups, then
during restore and crosscheck operations, you must allocate channels on multiple
nodes by providing the CONNECT option to the CONFIGURE CHANNEL command, so
that every backup can be accessed by at least one node. If some backups are not
accessible during crosscheck because no channel was configured on the node that can
access those backups, then those backups are marked EXPIRED in the RMAN
repository after the crosscheck.
For example, you can use CONFIGURE CHANNEL ... CONNECT in an Oracle RAC
configuration in which tape backups are created on various nodes in the cluster and
each backup is only accessible on the node on which it is created.
Related Topics:
Configuring Channels to Use a Specific Node
Oracle Database Backup and Recovery User’s Guide
Configuring Recovery Manager and Archiving 7-3
Configuring Channels for RMAN in Oracle RAC
Configuring Channels for RMAN in Oracle RAC
This section describes how to configure channels for RMAN. You can configure
channels to use automatic load balancing or you can specify specific channels for
specific instances as described in the following topics:
•
Configuring Channels to Use Automatic Load Balancing
•
Configuring Channels to Use a Specific Node
Configuring Channels to Use Automatic Load Balancing
To configure channels to use automatic load balancing, use the following syntax:
CONFIGURE DEVICE TYPE [disk | sbt] PARALLELISM number_of_channels;
...
Where number_of_channels is the number of channels that you want to use for the
operation. After you complete this one-time configuration, you can issue BACKUP or
RESTORE commands.
Configuring Channels to Use a Specific Node
To configure one RMAN channel for each policy-managed Oracle RAC database
instance, use the following syntax:
CONFIGURE CHANNEL DEVICE TYPE sbt CONNECT '@racinst_1'
CONFIGURE CHANNEL DEVICE TYPE sbt CONNECT '@racinst_2'
...
After this one-time configuration step, you can issue the BACKUP or RESTORE
commands.
Managing Archived Redo Logs Using RMAN in Oracle RAC
When a node generates an archived redo log, Oracle Database always records the file
name of the log in the control file of the target database. If you are using a recovery
catalog, then RMAN also records the archived redo log filenames in the recovery
catalog when a resynchronization occurs.
The archived redo log naming scheme that you use is important because when a node
writes to a log with a specific file name on its file system, the file must be readable by
any node that must access this archived redo log. For example, if node1 archives a log
to /oracle/arc_dest/log_1_100_23452345.arc, then node2 can back up this
archived redo log only if it can read /oracle/arc_dest/
log_1_100_23452345.arc on its own file system.
The backup and recovery strategy that you choose depends on how you configure the
archiving destinations for each node. Whether only one node or all nodes perform
archived redo log backups, you must ensure that all archived redo logs are backed up.
If you use RMAN parallelism during recovery, then the node that performs recovery
must have read access to all archived redo logs in your cluster.
Multiple nodes can restore archived logs in parallel. However, during recovery, only
one node applies the archived logs. Therefore, the node that is performing the
recovery must be able to access all of the archived logs that are needed for the
recovery operation. By default, the database determines the optimum number of
7-4 Oracle Real Application Clusters Administration and Deployment Guide
Archived Redo Log File Conventions in Oracle RAC
parallel threads to use during the recovery operation. You can use the PARALLEL
clause in the RECOVER command to change the number of parallel threads.
Guidelines and Considerations for Archived Redo Logs
The primary consideration is to ensure that all archived redo logs can be read from
every node during recovery, and, if possible, during backups. During recovery, if the
archived log destinations are visible from the node that performs the recovery, then
Oracle Database can successfully recover the archived log data.
Archived Redo Log File Conventions in Oracle RAC
For any archived redo log configuration, uniquely identify the archived redo logs with
the LOG_ARCHIVE_FORMAT parameter.
The format of this parameter is operating system-specific and it can include text
strings, one or more variables, and a file name extension.
Table 7-1
Archived Redo Log File Name Format Parameters
Parameter
Description
Example
%r
Resetlogs identifier, not padded
log_1_62_23452345
%R
Resetlogs identifier, left-zero-padded
log_1_62_0023452345
%s
Log sequence number, not padded
log_251
%S
Log sequence number, left-zeropadded
log_0000000251
%t
Thread number, not padded
log_1
%T
Thread number, left-zero-padded
log_0001
All of the file name format parameters for the archive redo logs, in either upper or
lowercase, are mandatory for Oracle RAC. These parameters enable Oracle Database
to create unique names for archive logs across the incarnation. This requirement is in
effect when the COMPATIBLE parameter is set to 10.0 or greater.
Use the %R or %r parameters to include the resetlogs identifier to avoid overwriting
the logs from a previous incarnation. If you do not specify a log format, then the
default is operating system-specific and includes %t, %s, and %r.
As an example, if the instance associated with redo thread number 1 sets
LOG_ARCHIVE_FORMAT to log_%t_%s_%r.arc, then its archived redo log files are
named:
log_1_1000_23435343.arc
log_1_1001_23452345.arc
log_1_1002_23452345.arc
...
Related Topics:
Oracle Database Administrator’s Guide
Configuring Recovery Manager and Archiving 7-5
RMAN Archiving Configuration Scenarios
RMAN Archiving Configuration Scenarios
This section describes the archiving scenarios for an Oracle RAC database. The two
configuration scenarios in this chapter describe a three-node UNIX cluster for an
Oracle RAC database. For both scenarios, the LOG_ARCHIVE_FORMAT that you specify
for the instance performing recovery must be the same as the format that you specified
for the instances that archived the redo log files.
This section includes the following topics:
•
Oracle Automatic Storage Management and Cluster File System Archiving
Scheme
•
Noncluster File System Local Archiving Scheme
Oracle Automatic Storage Management and Cluster File System Archiving Scheme
The preferred configuration for Oracle RAC is to use Oracle Automatic Storage
Management (Oracle ASM) for a recovery area using a disk group for your recovery
set that is different from the disk group used for your data files.
When you use Oracle ASM, it uses an Oracle Managed Files naming format.
Alternatively, you can use a cluster file system archiving scheme. If you use a cluster
file system, then each node writes to a single location on the cluster file system when
archiving the redo log files. Each node can read the archived redo log files of the other
nodes. For example, as shown in Figure 7-1, if Node 1 archives a redo log file to /
arc_dest/log_1_100_23452345.arc on the cluster file system, then any other
node in the cluster can also read this file.
Figure 7-1
Cluster File System Archiving Scheme
Note:
The archive log naming format in this example is only for a cluster file system
example.
7-6 Oracle Real Application Clusters Administration and Deployment Guide
RMAN Archiving Configuration Scenarios
If you do not use a cluster file system, then the archived redo log files cannot be on
raw devices. This is because raw devices do not enable sequential writing of
consecutive archive log files.
Related Topics:
Oracle Database Backup and Recovery User’s Guide
Advantages of the Cluster File System Archiving Scheme
The advantage of this scheme is that none of the nodes uses the network to archive
logs. Because the file name written by a node can be read by any node in the cluster,
RMAN can back up all logs from any node in the cluster. Backup and restore scripts
are simplified because each node has access to all archived redo logs.
Initialization Parameter Settings for the Cluster File System Archiving Scheme
In the cluster file system scheme, each node archives to a directory that is identified
with the same name on all instances within the cluster database (/arc_dest, in the
following example). To configure this directory, set values for the LOG_ARCH_DEST_1
parameter, as shown in the following example:
*.LOG_ARCHIVE_DEST_1="LOCATION=/arc_dest"
The following list shows archived redo log entry examples that would appear in the
RMAN catalog or in the control file based on the previous example. Note that any
node can archive logs using any of the threads:
/arc_dest/log_1_999_23452345.arc
/arc_dest/log_1_1000_23435343.arc
/arc_dest/log_1_1001_23452345.arc <- thread 1 archived in node3
/arc_dest/log_3_1563_23452345.arc <- thread 3 archived in node2
/arc_dest/log_2_753_23452345.arc <- thread 2 archived in node1
/arc_dest/log_2_754_23452345.arc
/arc_dest/log_3_1564_23452345.arc
Location of Archived Logs for the Cluster File System Archiving Scheme
Because the file system is shared and because each node is writing its archived redo
logs to the /arc_dest directory in the cluster file system, each node can read the logs
written by itself and any other node.
Noncluster File System Local Archiving Scheme
When archiving locally to a noncluster file system, each node archives to a uniquely
named local directory. If recovery is required, then you can configure the recovery
node so that it can access directories on the other nodes remotely. For example, use
NFS on Linux and UNIX computers, or mapped drives on Windows systems.
Therefore, each node writes only to a local destination, but each node can also read
archived redo log files in remote directories on the other nodes.
Considerations for Using Noncluster File System Local Archiving
If you use noncluster file system local archiving for media recovery, then you must
configure the node that is performing recovery for remote access to the other nodes so
that it can read the archived redo log files in the archive directories on the other nodes.
In addition, if you are performing recovery and you do not have all of the available
archive logs, then you must perform an incomplete recovery up to the first missing
archived redo log sequence number. You do not have to use a specific configuration
Configuring Recovery Manager and Archiving 7-7
RMAN Archiving Configuration Scenarios
for this scheme. However, to distribute the backup processing onto multiple nodes,
the easiest method is to configure channels as described in the backup scenarios in
"Managing Backup and Recovery".
Note:
Because different file systems are used in a noncluster case, the archive log
directories must be unique on each node. For example, /arc_dest_1 is only
available on node1, /arc_dest_2 is only directly mounted on node2, and
so on.
Then node1 mounts /arc_dest_2 from node2 and /arc_dest_3 from
node3 through NFS.
Related Topics:
Managing Backup and Recovery
Initialization Parameter Settings for Noncluster File System Local Archiving
You can set the archiving destination values as follows in the initialization parameter
file for either policy-managed or administrator-managed databases.
Set the SID.LOG_ARCH_DEST parameter for each instance using the SID designator,
as shown in the following example:
sid1.LOG_ARCHIVE_DEST_1="LOCATION=/arc_dest_1"
sid2.LOG_ARCHIVE_DEST_1="LOCATION=/arc_dest_2"
sid3.LOG_ARCHIVE_DEST_1="LOCATION=/arc_dest_3"
For policy-managed databases, manually create a node and instance binding to ensure
that sid1 always runs on the same node, as follows:
$ srvctl modify database -d mydb -n node1 -i sid1
$ srvctl modify database -d mydb -n node2 -i sid2
$ srvctl modify database -d mydb -n node3 -i sid3
The following list shows the possible archived redo log entries in the database control
file. Note that any node can read archived redo logs from any of the threads, which
must happen in order for the database to recover after a failure.
/arc_dest_1/log_1_1000_23435343.arc
/arc_dest_2/log_1_1001_23452345.arc <- thread 1 archived in node2
/arc_dest_2/log_3_1563_23452345.arc <- thread 3 archived in node2
/arc_dest_1/log_2_753_23452345.arc <- thread 2 archived in node1
/arc_dest_2/log_2_754_23452345.arc
/arc_dest_3/log_3_1564_23452345.arc
Location of Archived Logs for Noncluster File System Local Archiving
As illustrated in Table 7-2, each of three nodes has a directory containing the locally
archived redo logs. Additionally, if you mount directories on the other nodes remotely
through NFS or mapped drives, then each node has two remote directories through
which RMAN can read the archived redo log files that are archived by the remaining
nodes.
7-8 Oracle Real Application Clusters Administration and Deployment Guide
RMAN Archiving Configuration Scenarios
Note:
The archive log destinations, similar to those shown in Table 7-2, must be
different on each node so that if you mount the NFS directory on a different
node, then it does not conflict with an existing archive log directory
Table 7-2 UNIX/NFS Location Log Examples, Noncluster File System Local
Archiving
Node
Reads the archived redo log For logs archived by node
files in the directory
1
/arc_dest_1
1
1
/arc_dest_2
2 (through NFS)
1
/arc_dest_3
3 (through NFS)
2
/arc_dest_1
1 (through NFS)
2
/arc_dest_2
2
2
/arc_dest_3
3 (through NFS)
3
/arc_dest_1
1 (through NFS)
3
/arc_dest_2
2 (through NFS)
3
/arc_dest_3
3
File System Configuration for Noncluster File System Local Archiving
If you are performing recovery and a surviving instance must read all of the logs that
are on disk but not yet backed up, then you should configure NFS as shown in
Table 7-3.
Table 7-3
UNIX/NFS Configuration for Shared Read Local Archiving Examples
Node
Directory...
Is configured...
And mounted on...
On node...
1
/arc_dest_1
Local read/write
n/a
n/a
1
/arc_dest_2
NFS read
/arc_dest_2
2
1
/arc_dest_3
NFS read
/arc_dest_3
3
2
/arc_dest_1
NFS read
/arc_dest_1
1
2
/arc_dest_2
Local read/write
n/a
n/a
2
/arc_dest_3
NFS read
/arc_dest_3
3
3
/arc_dest_1
NFS read
/arc_dest_1
1
3
/arc_dest_2
NFS read
/arc_dest_2
2
3
/arc_dest_3
Local read/write
n/a
n/a
Configuring Recovery Manager and Archiving 7-9
Monitoring the Archiver Processes
Note:
Windows users can achieve the same results depicted in the examples in this
section by using mapped drives.
Monitoring the Archiver Processes
After your RMAN configuration is operative in your Oracle RAC environment, use
the GV$ARCHIVE_PROCESSES and V$ARCHIVE_PROCESSES views to determine the
status of the archiver processes. Depending on whether you query the global or local
views, these views display information for all database instances, or for only the
instance to which you are connected.
Note:
If you use the kill command to stop the archiver process, then the database
instance will fail.
Related Topics:
Oracle Database Administrator’s Guide
Oracle Database Reference
7-10 Oracle Real Application Clusters Administration and Deployment Guide
8
Managing Backup and Recovery
This chapter explains instance recovery and how to use Recovery Manager (RMAN) to
back up and restore Oracle Real Application Clusters (Oracle RAC) databases. This
chapter also describes Oracle RAC instance recovery, parallel backup, recovery with
SQL*Plus, and using the Fast Recovery Area in Oracle RAC. The topics in this chapter
include:
•
RMAN Backup Scenario for Noncluster File System Backups
•
RMAN Restore Scenarios for Oracle RAC
•
Instance Recovery in Oracle RAC
•
Media Recovery in Oracle RAC
•
Parallel Recovery in Oracle RAC
•
Using a Fast Recovery Area in Oracle RAC
Note:
For restore and recovery in Oracle RAC environments, you do not have to
configure the instance that performs the recovery to also be the sole instance
that restores all of the data files. In Oracle RAC, data files are accessible from
every node in the cluster, so any node can restore archived redo log files.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
See Also:
Oracle Clusterware Administration and Deployment Guide for information about
backing up and restoring the Oracle Clusterware components such as the
Oracle Cluster Registry (OCR) and the voting disk
RMAN Backup Scenario for Noncluster File System Backups
In a noncluster file system environment, each node can back up only to a locally
mounted noncluster file system directory. For example, node1 cannot access the
archived redo log files on node2 or node3 unless you configure the network file
system for remote access. If you configure a network file system file for backups, then
each node backs up its archived redo logs to a local directory.
Managing Backup and Recovery 8-1
RMAN Restore Scenarios for Oracle RAC
RMAN Restore Scenarios for Oracle RAC
This section describes the following common RMAN restore scenarios:
•
Restoring Backups from a Cluster File System
•
Restoring Backups from a Noncluster File System
•
Using RMAN or Oracle Enterprise Manager to Restore the Server Parameter File
(SPFILE)
Note:
The restore and recovery procedures in a cluster file system scheme do not
differ substantially from Oracle noncluster scenarios.
Restoring Backups from a Cluster File System
The scheme that this section describes assumes that you are using the "Oracle
Automatic Storage Management and Cluster File System Archiving Scheme". In this
scheme, assume that node3 performed the backups to a cluster file system. If node3 is
available for the restore and recovery operation, and if all of the archived logs have
been backed up or are on disk, then run the following commands to perform complete
recovery:
RESTORE DATABASE;
RECOVER DATABASE;
If node3 performed the backups but is unavailable, then configure a media
management device for one of the remaining nodes and make the backup media from
node3 available to this node.
Note:
If you configured RMAN as described in "Configuring Channels to Use
Automatic Load Balancing", then, to load balance the channels across nodes,
note that channels cannot be load balanced before at least one instance has
successfully opened the database. This means that the channels will not be
load balanced across the nodes during a full database restore. To achieve load
balancing of channels for RESTORE and RECOVER commands, you can
temporarily reallocate channels by running commands similar to the
following:
run {
ALLOCATE CHANNEL DEVICE TYPE sbt C1 CONNECT '@racinst_1'
ALLOCATE CHANNEL DEVICE TYPE sbt C2 CONNECT '@racinst_2'
...
}
8-2 Oracle Real Application Clusters Administration and Deployment Guide
Instance Recovery in Oracle RAC
Related Topics:
Oracle Automatic Storage Management and Cluster File System Archiving
Scheme
The preferred configuration for Oracle RAC is to use Oracle Automatic
Storage Management (Oracle ASM) for a recovery area using a disk
group for your recovery set that is different from the disk group used for
your data files.
Configuring Channels to Use Automatic Load Balancing
Restoring Backups from a Noncluster File System
The scheme that this section describes assumes that you are using the "Noncluster File
System Local Archiving Scheme". In this scheme, each node archives locally to a
different directory. For example, node1 archives to /arc_dest_1, node2 archives
to /arc_dest_2, and node3 archives to /arc_dest_3. You must configure a
network file system file so that the recovery node can read the archiving directories on
the remaining nodes.
If all nodes are available and if all archived redo logs have been backed up, then you
can perform a complete restore and recovery by mounting the database and running
the following commands from any node:
RESTORE DATABASE;
RECOVER DATABASE;
Because the network file system configuration enables each node read access to the
redo log files on other nodes, then the recovery node can read and apply the archived
redo logs located on the local and remote disks. No manual transfer of archived redo
logs is required.
Related Topics:
Noncluster File System Local Archiving Scheme
Using RMAN or Oracle Enterprise Manager to Restore the Server Parameter File
(SPFILE)
RMAN can restore the server parameter file either to the default location or to a
location that you specify.
You can also use Oracle Enterprise Manager to restore the SPFILE. From the Backup/
Recovery section of the Maintenance tab, click Perform Recovery. The Perform
Recovery link is context-sensitive and navigates you to the SPFILE restore only when
the database is closed.
Instance Recovery in Oracle RAC
Instance failure occurs when software or hardware problems disable an instance. After
instance failure, Oracle Database automatically uses the online redo logs to perform
recovery as described in this section.
This section includes the following topics:
•
Single Node Failure in Oracle RAC
•
Multiple-Node Failures in Oracle RAC
Managing Backup and Recovery 8-3
Instance Recovery in Oracle RAC
•
Using RMAN to Create Backups in Oracle RAC
•
Node Affinity Awareness of Fast Connections
•
Deleting Archived Redo Logs after a Successful Backup
•
Autolocation for Backup and Restore Commands
Single Node Failure in Oracle RAC
Instance recovery in Oracle RAC does not include the recovery of applications that
were running on the failed instance. Oracle Clusterware restarts the instance
automatically.
Applications that were running on a node before it failed continue running by using
failure recognition and recovery. This provides consistent and uninterrupted service if
hardware or software fails. When one instance performs recovery for another instance,
the surviving instance reads online redo logs generated by the failed instance and uses
that information to ensure that committed transactions are recorded in the database.
Thus, data from committed transactions is not lost. The instance performing recovery
rolls back transactions that were active at the time of the failure and releases resources
used by those transactions.
Note:
All online redo logs must be accessible for instance recovery. Therefore, Oracle
recommends that you mirror your online redo logs.
Multiple-Node Failures in Oracle RAC
When multiple node failures occur, if one instance survives, then Oracle RAC
performs instance recovery for any other instances that fail. If all instances of an Oracle
RAC database fail, then Oracle Database automatically recovers the instances the next
time one instance opens the database. The instance performing recovery can mount
the database in either cluster database or exclusive mode from any node of an Oracle
RAC database. This recovery procedure is the same for Oracle Database running in
shared mode as it is for Oracle Database running in exclusive mode, except that one
instance performs instance recovery for all of the failed instances.
Using RMAN to Create Backups in Oracle RAC
Oracle Database provides RMAN for backing up and restoring the database.
RMAN enables you to back up, restore, and recover data files, control files, SPFILEs,
and archived redo logs. RMAN is included with the Oracle Database server and it is
installed by default. You can run RMAN from the command line or you can use it
from the Backup Manager in Oracle Enterprise Manager. In addition, RMAN is the
recommended backup and recovery tool if you are using Oracle Automatic Storage
Management (Oracle ASM). The procedures for using RMAN in Oracle RAC
environments do not differ substantially from those for Oracle noncluster
environments.
Related Topics:
Oracle Database Backup and Recovery User’s Guide
8-4 Oracle Real Application Clusters Administration and Deployment Guide
Instance Recovery in Oracle RAC
Channel Connections to Cluster Instances with RMAN
Channel connections to the instances are determined using the connect string defined
by channel configurations. For example, in the following configuration, three channels
are allocated using dbauser/[email protected]_name. If you configure the SQL Net
service name with load balancing turned on, then the channels are allocated at a node
as decided by the load balancing algorithm.
CONFIGURE DEVICE TYPE sbt PARALLELISM 3;
CONFIGURE DEFAULT DEVICE TYPE TO sbt;
CONFIGURE CHANNEL DEVICE TYPE SBT CONNECT 'dbauser/[email protected]_name'
However, if the service name used in the connect string is not for load balancing, then
you can control at which instance the channels are allocated using separate connect
strings for each channel configuration, as follows:
CONFIGURE
CONFIGURE
CONFIGURE
CONFIGURE
DEVICE TYPE
CHANNEL 1..
CHANNEL 2..
CHANNEL 3..
sbt PARALLELISM 3;
CONNECT 'dbauser/[email protected]_1';
CONNECT 'dbauser/[email protected]_2';
CONNECT 'dbauser/[email protected]_3';
In the previous example, it is assumed that mydb_1, mydb_2 and mydb_3 are
SQL*Net service names that connect to pre-defined nodes in your Oracle RAC
environment. Alternatively, you can also use manually allocated channels to backup
your database files. For example, the following command backs up the SPFILE, control
file, data files and archived redo logs:
RUN
{
ALLOCATE CHANNEL CH1
ALLOCATE CHANNEL CH2
ALLOCATE CHANNEL CH3
BACKUP DATABASE PLUS
CONNECT 'dbauser/[email protected]_1';
CONNECT 'dbauser/[email protected]_2';
CONNECT 'dbauser/[email protected]_3';
ARCHIVED LOG;
}
During a backup operation, if at least one channel allocated has access to the archived
log, then RMAN automatically schedules the backup of the specific log on that
channel. Because the control file, SPFILE, and data files are accessible by any channel,
the backup operation of these files is distributed across the allocated channels.
For a local archiving scheme, there must be at least one channel allocated to all of the
nodes that write to their local archived logs. For a cluster file system archiving scheme,
if every node writes the archived logs in the same cluster file system, then the backup
operation of the archived logs is distributed across the allocated channels.
During a backup, the instances to which the channels connect must be either all
mounted or all open. For example, if the instance on node1 has the database mounted
while the instances on node2 and node3 have the database open, then the backup
fails.
See Also:
Oracle Database Backup and Recovery Reference for more information about the
CONNECT clause of the CONFIGURE CHANNEL statement
Managing Backup and Recovery 8-5
Instance Recovery in Oracle RAC
Related Topics:
Oracle Database Backup and Recovery Reference
Node Affinity Awareness of Fast Connections
In some cluster database configurations, some nodes of the cluster have faster access to
certain data files than to other data files. RMAN automatically detects this situation,
which is known as node affinity awareness. When deciding which channel to use to
back up a particular data file, RMAN gives preference to the nodes with faster access
to the data files that you want to back up. For example, if you have a three-node
cluster, and if node1 has faster read/write access to data files 7, 8, and 9 than the other
nodes, then node1 has greater node affinity to those files than node2 and node3.
Deleting Archived Redo Logs after a Successful Backup
If you have configured the automatic channels as defined in section "Channel
Connections to Cluster Instances with RMAN", then you can use the following
example to delete the archived logs that you backed up n times. The device type can
be DISK or SBT:
DELETE ARCHIVELOG ALL BACKED UP n TIMES TO DEVICE TYPE device_type;
During a delete operation, if at least one channel allocated has access to the archived
log, then RMAN automatically schedules the deletion of the specific log on that
channel. For a local archiving scheme, there must be at least one channel allocated that
can delete an archived log. For a cluster file system archiving scheme, if every node
writes to the archived logs on the same cluster file system, then the archived log can be
deleted by any allocated channel.
If you have not configured automatic channels, then you can manually allocate the
maintenance channels as follows and delete the archived logs.
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE
DELETE ARCHIVELOG ALL BACKED UP n TIMES
TYPE DISK
TYPE DISK
TYPE DISK
TO DEVICE
CONNECT 'SYS/[email protected]';
CONNECT 'SYS/[email protected]';
CONNECT 'SYS/[email protected]';
TYPE device_type;
Related Topics:
Channel Connections to Cluster Instances with RMAN
Autolocation for Backup and Restore Commands
RMAN automatically performs autolocation of all files that it must back up or restore.
If you use the noncluster file system local archiving scheme, then a node can only read
the archived redo logs that were generated by an instance on that node. RMAN never
attempts to back up archived redo logs on a channel it cannot read.
During a restore operation, RMAN automatically performs the autolocation of
backups. A channel connected to a specific node only attempts to restore files that
were backed up to the node. For example, assume that log sequence 1001 is backed up
to the drive attached to node1, while log 1002 is backed up to the drive attached to
node2. If you then allocate channels that connect to each node, then the channel
connected to node1 can restore log 1001 (but not 1002), and the channel connected to
node2 can restore log 1002 (but not 1001).
8-6 Oracle Real Application Clusters Administration and Deployment Guide
Media Recovery in Oracle RAC
Media Recovery in Oracle RAC
Media recovery must be user-initiated through a client application, whereas instance
recovery is automatically performed by the database. In these situations, use RMAN to
restore backups of the data files and then recover the database. The procedures for
RMAN media recovery in Oracle RAC environments do not differ substantially from
the media recovery procedures for noncluster environments.
The node that performs the recovery must be able to restore all of the required data
files. That node must also be able to either read all of the required archived redo logs
on disk or be able to restore them from backups.
When recovering a database with encrypted tablespaces (for example after a
SHUTDOWN ABORT or a catastrophic error that brings down the database instance),
you must open the Oracle Wallet after database mount and before you open the
database, so the recovery process can decrypt data blocks and redo.
Parallel Recovery in Oracle RAC
Oracle Database automatically selects the optimum degree of parallelism for instance,
crash, and media recovery.
Oracle Database applies archived redo logs using an optimal number of parallel
processes based on the availability of CPUs. You can use parallel instance recovery
and parallel media recovery in Oracle RAC databases as described under the
following topics:
•
Parallel Recovery with RMAN
•
Disabling Parallel Recovery
Related Topics:
Oracle Database Backup and Recovery User’s Guide
Parallel Recovery with RMAN
With RMAN's RESTORE and RECOVER commands, Oracle Database automatically
makes parallel the following three stages of recovery:
Restoring Data Files
When restoring data files, the number of channels you allocate in the RMAN recover
script effectively sets the parallelism that RMAN uses. For example, if you allocate five
channels, you can have up to five parallel streams restoring data files.
Applying Incremental Backups
Similarly, when you are applying incremental backups, the number of channels you
allocate determines the potential parallelism.
Applying Archived Redo Logs
With RMAN, the application of archived redo logs is performed in parallel. Oracle
Database automatically selects the optimum degree of parallelism based on available
CPU resources.
Managing Backup and Recovery 8-7
Using a Fast Recovery Area in Oracle RAC
Disabling Parallel Recovery
You can override parallel recovery using the procedures under the following topics:
•
Disabling Instance and Crash Recovery Parallelism
•
Disabling Media Recovery Parallelism
Disabling Instance and Crash Recovery Parallelism
To disable parallel instance and crash recovery on a system with multiple CPUs, set
the RECOVERY_PARALLELISM parameter in the database initialization parameter file,
SPFILE, to 0 or 1.
Disabling Media Recovery Parallelism
Use the NOPARALLEL clause of the RMAN RECOVER command or the ALTER
DATABASE RECOVER statement to force Oracle Database to use non-parallel media
recovery.
Using a Fast Recovery Area in Oracle RAC
To use a fast recovery area in Oracle RAC, you must place it on an Oracle ASM disk
group, on a Cluster File System, or on a shared directory that is configured through a
network file system file for each Oracle RAC instance.
In other words, the fast recovery area must be shared among all of the instances of an
Oracle RAC database. In addition, set the parameter DB_RECOVERY_FILE_DEST to
the same value on all instances.
Oracle Enterprise Manager enables you to set up a fast recovery area. To use this
feature:
1.
From the Cluster Database home page, click the Maintenance tab.
2.
Under the Backup/Recovery options list, click Configure Recovery Settings.
3.
Specify your requirements in the Fast Recovery Area section of the page.
4.
Click Help on this page for more information.
Related Topics:
Oracle Database Backup and Recovery User’s Guide
8-8 Oracle Real Application Clusters Administration and Deployment Guide
9
Cloning Oracle RAC to Nodes in a New
Cluster
This chapter describes how to clone Oracle Real Application Clusters (Oracle RAC)
database homes on Linux and UNIX systems to nodes in a new cluster.
This chapter describes a noninteractive cloning technique that you implement with
scripts. The cloning techniques described in this chapter are best suited for performing
multiple simultaneous cluster installations. Creating the scripts is a manual process
and can be error prone. If you only have one cluster to install, then you should use the
traditional automated and interactive installation methods, such as Oracle Universal
Installer, or the Provisioning Pack feature of Oracle Enterprise Manager.
Note:
Cloning is not a replacement for Oracle Enterprise Manager cloning that is a
part of the Provisioning Pack. During Oracle Enterprise Manager cloning, the
provisioning process interactively asks you the details about the Oracle home
(such as the location to which you want to deploy the clone, the name of the
Oracle Database home, a list of the nodes in the cluster, and so on).
The Provisioning Pack feature of Oracle Enterprise Manager Cloud Control
provides a framework to make it easy for you to automate the provisioning of
new nodes and clusters. For data centers with many Oracle RAC clusters, the
investment in creating a cloning procedure to easily provision new clusters
and new nodes to existing clusters is worth the effort.
This chapter includes the following topics:
•
Introduction to Cloning Oracle RAC
•
Preparing to Clone Oracle RAC
•
Deploying Oracle RAC Clone to Nodes in a Cluster
•
Locating and Viewing Log Files Generated During Cloning
Related Topics:
Using Cloning to Extend Oracle RAC to Nodes in the Same Cluster
Introduction to Cloning Oracle RAC
Cloning is the process of copying an existing Oracle RAC installation to a different
location and updating the copied bits to work in the new environment. The changes
made by one-off patches applied on the source Oracle home, would also be present
Cloning Oracle RAC to Nodes in a New Cluster 9-1
Preparing to Clone Oracle RAC
after the clone operation. The source and the destination path (host to be cloned) need
not be the same.
Some situations in which cloning is useful are:
•
Cloning provides a way to prepare an Oracle home once and deploy it to many
hosts simultaneously. You can complete the installation silently, as a
noninteractive process. You do not need to use a graphical user interface (GUI)
console and you can perform cloning from a Secure Shell (SSH) terminal session,
if required.
•
Cloning enables you to create an installation (copy of a production, test, or
development installation) with all patches applied to it in a single step. Once you
have performed the base installation and applied all patch sets and patches on the
source system, the clone performs all of these individual steps as a single
procedure. This is in contrast to going through the installation process to perform
the separate steps to install, configure, and patch the installation on each node in
the cluster.
•
Installing Oracle RAC by cloning is a very quick process. For example, cloning an
Oracle home to a new cluster of more than two nodes requires a few minutes to
install the Oracle base software, plus a few minutes more for each node
(approximately the amount of time it takes to run the root.sh script).
The cloned installation behaves the same as the source installation. For example, the
cloned Oracle home can be removed using Oracle Universal Installer or patched using
OPatch. You can also use the cloned Oracle home as the source for another cloning
operation. You can create a cloned copy of a test, development, or production
installation by using the command-line cloning scripts. The default cloning procedure
is adequate for most usage cases. However, you can also customize various aspects of
cloning, for example, to specify custom port assignments, or to preserve custom
settings.
The cloning process works by copying all of the files from the source Oracle home to
the destination Oracle home. Thus, any files used by the source instance that are
located outside the source Oracle home's directory structure are not copied to the
destination location.
The size of the binaries at the source and the destination may differ because these are
relinked as part of the clone operation and the operating system patch levels may also
differ between these two locations. Additionally, the number of files in the cloned
home would increase because several files copied from the source, specifically those
being instantiated, are backed up as part of the clone operation.
Preparing to Clone Oracle RAC
Use this overview to understand the procedures you use to clone Oracle RAC.
In the preparation phase, you create a copy of an Oracle home that you then use to
perform the cloning procedure on one or more nodes. You also install Oracle
Clusterware.
Install Oracle RAC
Use the detailed instructions in Oracle Real Application Clusters Installation Guide for
your platform for your platform to install the Oracle RAC software and patches:
1.
Install Oracle RAC and choose the Software only installation option.
9-2 Oracle Real Application Clusters Administration and Deployment Guide
Deploying Oracle RAC Clone to Nodes in a Cluster
2.
Patch the release to the required level (for example, 12.1.0.n).
3.
Apply one-off patches, if necessary.
Create a backup of the source home
Create a copy of the Oracle RAC home. Use this file to copy the Oracle RAC home to
each node in the cluster.
When creating the backup (tar) file, the best practice is to include the release number
in the name of the file. For example:
# cd /opt/oracle/product/12c/db_1
# tar –zcvf /pathname/db1120.tgz .
Install and start Oracle Clusterware
Before you can use cloning to create an Oracle RAC home, you must first install and
start Oracle Clusterware on the node or nodes to which you want to copy a cloned
Oracle RAC home. In other words, you configure an Oracle RAC home that you
cloned from a source cluster onto the nodes in a target cluster in the same order that
you installed the Oracle Clusterware and Oracle RAC software components on the
original nodes.
Related Topics:
Oracle Real Application Clusters Installation Guide
Deploying Oracle RAC Clone to Nodes in a Cluster
Oracle Clusterware Administration and Deployment Guide
Deploying Oracle RAC Clone to Nodes in a Cluster
After you complete the prerequisite tasks described in "Preparing to Clone Oracle
RAC", you can deploy cloned Oracle homes.
Deploy the Oracle RAC database home to a cluster, as follows:
1.
2.
Perform any Oracle RAC preinstallation tasks, as described in your platformspecific Oracle RAC installation guide, to prepare the new cluster nodes, such
things as:
•
Specify the kernel parameters.
•
Ensure Oracle Clusterware is active.
•
Ensure that Oracle ASM is active and that at least one Oracle ASM disk group
exists and is mounted.
Deploy the Oracle RAC database software, as follows:
a.
Copy the clone of the Oracle home to all nodes. For example:
[[email protected] root]# mkdir -p /opt/oracle/product/12c/db
[[email protected] root]# cd /opt/oracle/product/12c/db
[[email protected] db]# tar –zxvf /path_name/db1120.tgz
Cloning Oracle RAC to Nodes in a New Cluster 9-3
Deploying Oracle RAC Clone to Nodes in a Cluster
When providing the home location and path_name, the home location can be
in the same directory path or in a different directory path from the source
home that you used to create the tar.
b.
If either the oracle user or the oinstall group, or both is different
between the source and destination nodes, then change the ownership of the
Oracle Inventory files, as follows:
[[email protected]]# chown -R oracle:oinstall /opt/oracle/product/12c/db
When you run the preceding command on the Oracle RAC home, it clears
setuid and setgid information from the Oracle binary.
Note:
You can perform this step at the same time you perform Step 3 and Step 4 to
run the clone.pl and $ORACLE_HOME/root.sh scripts on each cluster
node.
3.
Run the clone.pl script on each node, which performs the main Oracle RAC
cloning tasks, as follows:
a.
Supply the environment variables and cloning parameters in the start.sh
script, as described in Table 9-2 and Table 9-3. Because the clone.pl script is
sensitive to the parameters being passed to it, you must be accurate in your
use of brackets, single quotation marks, and double quotation marks.
b.
Run the script as oracle or the user that owns the Oracle RAC software.
The following table lists and describes the clone.pl script parameters:
Table 9-1
clone.pl Script Parameters
Parameter
Description
ORACLE_HOME=Oracl
e_home
The complete path to the Oracle home you want to clone. If
you specify an invalid path, then the script exits. This
parameter is required.
ORACLE_BASE=ORACL
E_BASE
The complete path to the Oracle base you want to clone. If you
specify an invalid path, then the script exits. This parameter is
required.
ORACLE_HOME_NAME=
Oracle_home_name
| defaultHomeName
The Oracle home name of the home you want to clone.
Optionally, you can specify the -defaultHomeName flag.
This parameter is optional.
ORACLE_HOME_USER=
Oracle_home_user
The OracleHomeUser for Windows services. This parameter is
applicable to Windows only and is optional.
OSDBA_GROUP=group
_name
Specify the operating system group you want to use as the
OSDBA privileged group. This parameter is optional.
OSOPER_GROUP=grou
p_name
Specify the operating system group you want to use as the
OSOPER privileged group. This parameter is optional.
OSASM_GROUP=group
_name
Specify the operating system group you want to use as the
OSASM privileged group. This parameter is optional.
9-4 Oracle Real Application Clusters Administration and Deployment Guide
Deploying Oracle RAC Clone to Nodes in a Cluster
Table 9-1
(Cont.) clone.pl Script Parameters
Parameter
Description
OSBACKUPDBA_GROUP
=group_name
Specify the operating system group you want to use as the
OSBACKUPDBA privileged group. This parameter is optional.
OSDGDBA_GROUP=gro
up_name
Specify the operating system group you want to use as the
OSDGDBA privileged group. This parameter is optional.
OSKMDBA_GROUP=gro
up_name
Specify the operating system group you want to use as the
OSKMDBA privileged group. This parameter is optional.
-debug
Specify this option to run the clone.pl script in debug mode
-help
Specify this option to obtain help for the clone.pl script.
The following example shows an excerpt from the start.sh script that calls the
clone.pl script:
ORACLE_BASE=/opt/oracle
ORACLE_HOME=/opt/oracle/product/12c/db
cd $ORACLE_HOME/clone
THISNODE='host_name'
E01=ORACLE_HOME=/opt/oracle/product/12c/db
E02=ORACLE_HOME_NAME=OraDBRAC
E03=ORACLE_BASE=/opt/oracle
C01="-O CLUSTER_NODES={node1,node2}"
C02="-O LOCAL_NODE=$THISNODE"
perl $ORACLE_HOME/clone/bin/clone.pl $E01 $E02 $E03 $C01 $C02
The following table lists and describes the environment variables E01, E02, and
E03 that are shown in bold typeface in the preceding example:
Table 9-2
Environment Variables Passed to the clone.pl Script
Symbol Variable
Description
E01
ORACLE_HOME
The location of the Oracle RAC database home. This
directory location must exist and must be owned by the
Oracle operating system group: oinstall.
E02
ORACLE_HOME_
NAME
The name of the Oracle home for the Oracle RAC database.
This is stored in the Oracle Inventory.
E03
ORACLE_BASE
The location of the Oracle Base directory.
The following table lists and describes the cloning parameters C01 and C02, that
are shown in bold typeface in the preceding example:
Table 9-3
Cloning Parameters Passed to the clone.pl Script.
Variabl
e
Name
Parameter
Description
C01
Cluster Nodes
CLUSTER_NODE
S
Lists the nodes in the cluster.
Cloning Oracle RAC to Nodes in a New Cluster 9-5
Deploying Oracle RAC Clone to Nodes in a Cluster
Table 9-3
(Cont.) Cloning Parameters Passed to the clone.pl Script.
Variabl
e
Name
Parameter
Description
C02
Local Node
LOCAL_NODE
The name of the local node.
The following example shows an excerpt from the start.bat script that the user
must create that calls the clone.pl script:
set ORACLE_home=C:\oracle\product\12c\db1
cd %ORACLE_home%\clone\bin
set THISNODE=%hostname%
set E01=ORACLE_HOME=%ORACLE_home%
set E02=ORACLE_HOME_NAME=OraDBRAC
set E03=ORACLE_BASE=Oracle_Base
set C01="CLUSTER_NODES={node1,node2}"
set C02="-O LOCAL_NODE=%THISNODE%"
perl clone.pl %E01% %E02% %E03% %C01% %C02%
4.
Note:
This step applies to Linux and UNIX installations, only.
Run the $ORACLE_HOME/root.sh as the root operating system user as soon as
the clone.pl procedure completes on the node.
[[email protected] root]# /opt/oracle/product/12c/db/root.sh -silent
Note that you can run the script on each node simultaneously:
[[email protected] root]# /opt/oracle/product/12c/db/root.sh -silent
Ensure the script has completed on each node before proceeding to the next step.
5.
Note:
You need only run DBCA on one node in the cluster to create Oracle RAC
instances on all nodes.
This step shows how to run DBCA in silent mode and provide response file input
to create the Oracle RAC instances.
The following example creates an Oracle RAC database named ERI on each node,
creates database instances on each node, registers the instances in OCR, creates
the database files in the Oracle ASM disk group called DATA, and creates sample
schemas. It also sets the SYS, SYSTEM, SYSMAN and DBSNMP passwords to
password, which is the password for each account:
[[email protected] oracle]$ export ORACLE_HOME=/opt/oracle/product/12c/db
[[email protected] oracle]$ cd $ORACLE_HOME/bin/
[[email protected] bin]$./dbca -silent -createDatabase -templateName
General_Purpose.dbc \
-gdbName ERI -sid ERI \
-sysPassword password -systemPassword password \
-sysmanPassword password -dbsnmpPassword password \
-emConfiguration LOCAL \
-storageType ASM -diskGroupName DATA \
9-6 Oracle Real Application Clusters Administration and Deployment Guide
Locating and Viewing Log Files Generated During Cloning
-datafileJarLocation $ORACLE_HOME/assistants/dbca/templates \
-nodelist node1,node2 -characterset WE8ISO8859P1 \
-obfuscatedPasswords false -sampleSchema true
Related Topics:
Preparing to Clone Oracle RAC
Use this overview to understand the procedures you use to clone Oracle
RAC.
Oracle Real Application Clusters Installation Guide
Oracle Database 2 Day DBA
Locating and Viewing Log Files Generated During Cloning
The cloning script runs multiple tools, each of which may generate its own log files.
After the clone.pl script finishes running, you can view log files to obtain more
information about the cloning process.
The following log files that are generated during cloning are the key log files of
interest for diagnostic purposes:
•
Central_Inventory/logs/cloneActionstimestamp.log
Contains a detailed log of the actions that occur during the Oracle Universal
Installer part of the cloning.
•
Central_Inventory/logs/oraInstalltimestamp.err
Contains information about errors that occur when Oracle Universal Installer is
running.
•
Central_Inventory/logs/oraInstalltimestamp.out
Contains other miscellaneous messages generated by Oracle Universal Installer.
•
$ORACLE_HOME/clone/logs/clonetimestamp.log
Contains a detailed log of the actions that occur before cloning and during the
cloning operations.
•
$ORACLE_HOME/clone/logs/errortimestamp.log
Contains information about errors that occur before cloning and during cloning
operations.
Table 9-4 describes how to find the location of the Oracle inventory directory.
Table 9-4
Finding the Location of the Oracle Inventory Directory
Type of System...
Location of the Oracle Inventory Directory
All UNIX computers
except Linux and IBM
AIX
/var/opt/oracle/oraInst.loc
IBM AIX and Linux
/etc/oraInst.loc file.
Windows
C:\Program Files\Oracle\Inventory
Cloning Oracle RAC to Nodes in a New Cluster 9-7
Locating and Viewing Log Files Generated During Cloning
9-8 Administration and Deployment Guide
10
Using Cloning to Extend Oracle RAC to
Nodes in the Same Cluster
This chapter provides information about using cloning to extend Oracle Real
Application Clusters (Oracle RAC) to nodes in an existing cluster.
To add Oracle RAC to nodes in a new cluster, see Cloning Oracle RAC to Nodes in a
New Cluster.
This chapter contains the following topics:
•
About Adding Nodes Using Cloning in Oracle RAC Environments
•
Cloning Local Oracle Homes on Linux and UNIX Systems
•
Cloning Shared Oracle Homes on Linux and UNIX Systems
•
Cloning Oracle Homes on Windows Systems
Related Topics:
Cloning Oracle RAC to Nodes in a New Cluster
This chapter describes how to clone Oracle Real Application Clusters
(Oracle RAC) database homes on Linux and UNIX systems to nodes in a
new cluster.
Introduction to Cloning Oracle RAC
Oracle Clusterware Administration and Deployment Guide
About Adding Nodes Using Cloning in Oracle RAC Environments
The cloning procedures assume that you have successfully installed and configured an
Oracle RAC environment to which you want to add nodes and instances. To add
nodes to an Oracle RAC environment using cloning, first extend the Oracle
Clusterware configuration, then extend the Oracle Database software with Oracle
RAC, and then add the listeners and instances by running the Oracle assistants
The cloning script runs multiple tools, each of which may generate its own log files.
After the clone.pl script finishes running, you can view log files to obtain more
information about the cloning process. See "Locating and Viewing Log Files Generated
During Cloning" for more information.
Cloning Local Oracle Homes on Linux and UNIX Systems
Add nodes to existing Oracle RAC environments by cloning a local (non-shared)
Oracle home in Linux and UNIX system environments.
Complete the following steps to clone Oracle Database with Oracle RAC software:
Using Cloning to Extend Oracle RAC to Nodes in the Same Cluster 10-1
Cloning Shared Oracle Homes on Linux and UNIX Systems
1.
Follow the steps in the "Preparing to Clone Oracle RAC" to create a copy of an
Oracle home that you then use to perform the cloning procedure on one or more
nodes.
2.
Use the tar utility to create an archive of the Oracle home on the existing node
and copy it to the new node. If the location of the Oracle home on the source node
is $ORACLE_HOME, then you must use this same directory as the destination
location on the new node.
3.
On the new node, configure the environment variables ORACLE_HOME and
ORACLE_BASE. Then go to the $ORACLE_HOME/clone/bin directory and run
the following command, where existing_node is the name of the node that you
are cloning, new_node2 and new_node3 are the names of the new nodes, and
Oracle_home_name is the name of the Oracle home:
perl clone.pl -O 'CLUSTER_NODES={existing_node,new_node2,new_node3}'
-O LOCAL_NODE=new_node2 ORACLE_BASE=$ORACLE_BASE ORACLE_HOME=$ORACLE_HOME
ORACLE_HOME_NAME=Oracle_home_name -O -noConfig
4.
Run the following command to run the configuration assistants to configure
Oracle RAC on the new nodes:
$ORACLE_HOME/cfgtoollogs/configToolFailedCommands
This script contains all commands that failed, were skipped, or were canceled
during the installation. You can use this script to run the database configuration
assistants outside of Oracle Universal Installer. Note that before you run the script
you should check the script to see if any passwords within it need to be updated.
5.
Run the following command on the existing node from the
$ORACLE_HOME/oui/bin directory to update the inventory in the Oracle
Database home with Oracle RAC, specified by Oracle_home, where
existing_node is the name of the original node that you are cloning and
new_node2 and new_node3 are the names of the new nodes:
./runInstaller -updateNodeList ORACLE_HOME=$ORACLE_HOME -O "CLUSTER_NODES=
{existing_node,new_node2,new_node3}"
6.
On each new node, go to the $ORACLE_HOME directory and run the following
command:
./root.sh
7.
From the node that you cloned, run Database Configuration Assistant (DBCA) to
add Oracle RAC database instances on the new nodes.
Related Topics:
Preparing to Clone Oracle RAC
Use this overview to understand the procedures you use to clone Oracle
RAC.
Cloning Shared Oracle Homes on Linux and UNIX Systems
Add nodes to existing Oracle RAC environments by cloning a shared Oracle home in
Linux and UNIX system environments.
Complete the following steps to clone Oracle Database with Oracle RAC software:
10-2 Oracle Real Application Clusters Administration and Deployment Guide
Cloning Oracle Homes on Windows Systems
1.
Follow the steps in the "Preparing to Clone Oracle RAC" to create a copy of an
Oracle home that you then use to perform the cloning procedure on one or more
nodes.
2.
On the new node, configure the environment variables ORACLE_HOME and
ORACLE_BASE. Then go to the $ORACLE_HOME/clone/bin directory and run
the following command, where existing_node is the name of the node that you
are cloning, new_node2, and new_node3 are the names of the new nodes,
Oracle_home_name is the name of the Oracle home, and the -cfs option
indicates the Oracle home is shared:
perl clone.pl -O 'CLUSTER_NODES={existing_node,new_node2,new_node3}'
-O LOCAL_NODE=new_node2 ORACLE_BASE=$ORACLE_BASE ORACLE_HOME=$ORACLE_HOME
ORACLE_HOME_NAME=Oracle_home_name [-cfs]
Note:
In the preceding command:
3.
•
Use the -cfs option for a shared Oracle Database home with Oracle
RAC.
•
The value for the ORACLE_HOME_NAME parameter must be that of the
node you are cloning.
Run the following command on the existing node from the
$ORACLE_HOME/oui/bin directory to update the inventory in the Oracle
Database home with Oracle RAC, specified by Oracle_home, where
existing_node is the name of the original node that you are cloning and
new_node2 and new_node3 are the names of the new nodes:
./runInstaller -updateNodeList ORACLE_HOME=$ORACLE_HOME "CLUSTER_NODES=
{existing_node,new_node2,new_node3}"
4.
On each new node, go to the $ORACLE_HOME directory and run the following
command:
./root.sh
5.
From the node that you cloned, run Database Configuration Assistant (DBCA) to
add Oracle RAC database instances to the new nodes.
Related Topics:
Preparing to Clone Oracle RAC
Use this overview to understand the procedures you use to clone Oracle
RAC.
Cloning Oracle Homes on Windows Systems
Add nodes to existing Oracle RAC environments by cloning a shared or local Oracle
home in Windows system environments.
Complete the following steps to clone Oracle Database with Oracle RAC software:
1.
If you have a local Oracle home, then use the ZIP utility to create an archive of the
Oracle Database home with Oracle RAC on the existing node and copy it to the
new node. Otherwise, proceed to the next step.
Using Cloning to Extend Oracle RAC to Nodes in the Same Cluster 10-3
Cloning Oracle Homes on Windows Systems
Extract the Oracle Database with Oracle RAC home files from the ZIP file on the
new node in the same directory in which the Oracle Database home with Oracle
RAC resided on the existing node. For example, assume that the location of the
destination Oracle RAC home on the new node is %ORACLE_HOME%.
2.
On the new node, go to the %ORACLE_HOME%\clone\bin directory and run the
following command, where Oracle_Home is the Oracle Database home,
Oracle_Home_Name is the name of the Oracle Database home, Oracle_Base is
the Oracle base directory, user_name is the name of the Oracle home user (a nonAdministrator user) for the Oracle home being cloned, existing_node is the
name of the existing node, and new_node is the name of the new node:
perl clone.pl ORACLE_HOME=Oracle_Home ORACLE_BASE=Oracle_Base
ORACLE_HOME_NAME=Oracle_Home_Name ORACLE_HOME_USER=user_name
-O 'CLUSTER_NODES={existing_node,new_node}'
-O LOCAL_NODE=new_node
If you have a shared Oracle Database home with Oracle RAC, then append the cfs option to the command to indicate that the Oracle home is shared, as shown
in the following example:
perl clone.pl ORACLE_HOME=Oracle_Home ORACLE_BASE=Oracle_Base
ORACLE_HOME_NAME=Oracle_Home_Name ORACLE_HOME_USER=user_name
-O 'CLUSTER_NODES={existing_node,new_node}' -O LOCAL_NODE=new_node
[-cfs -noConfig]
Note:
3.
•
The ORACLE_HOME_USER is required only if you are cloning a secured
Oracle home.
•
Use the -cfs and -noConfig options for a shared Oracle Database home
with Oracle RAC.
•
The value for the ORACLE_HOME_NAME parameter must be that of the
node you are cloning. To obtain the ORACLE_HOME_NAME, look in the
registry on the node you cloning for the ORACLE_HOME_NAME parameter
key under HKEY_LOCAL_MACHINE\SOFTWARE\oracle
\KEY_OraCRs12c_home1.
On the existing node, from the %ORACLE_HOME%\oui\bin directory run the
following command to update the inventory in the Oracle Database home with
Oracle RAC, specified by Oracle_home, where existing_node is the name of
the existing node, and new_node is the name of the new node:
setup.exe -updateNodeList ORACLE_HOME=Oracle_home "CLUSTER_NODES=
{existing_node,new_node}" LOCAL_NODE=existing_node
4.
From the node that you cloned, run DBCA to add Oracle RAC database instances
to the new nodes.
10-4 Oracle Real Application Clusters Administration and Deployment Guide
11
Adding and Deleting Oracle RAC from
Nodes on Linux and UNIX Systems
Extend an existing Oracle Real Application Clusters (Oracle RAC) home to other
nodes and instances in the cluster, and delete Oracle RAC from nodes and instances in
the cluster.
If your goal is to clone an existing Oracle RAC home to create multiple new Oracle
RAC installations across the cluster, then use the cloning procedures that are described
in "Cloning Oracle RAC to Nodes in a New Cluster".
The topics in this chapter include the following:
•
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
•
Deleting Oracle RAC from a Cluster Node
Note:
•
Ensure that you have a current backup of Oracle Cluster Registry (OCR)
before adding or deleting Oracle RAC by running the ocrconfig showbackup command.
•
The phrase "target node" as used in this chapter refers to the node to
which you plan to extend the Oracle RAC environment.
Related Topics:
Cloning Oracle RAC to Nodes in a New Cluster
This chapter describes how to clone Oracle Real Application Clusters
(Oracle RAC) database homes on Linux and UNIX systems to nodes in a
new cluster.
Oracle Database 2 Day + Real Application Clusters Guide
Adding and Deleting Oracle RAC from Nodes on Windows Systems
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Before beginning this procedure, ensure that your existing nodes have the correct path
to the Grid_home and that the $ORACLE_HOME environment variable is set to the
Oracle RAC home.
•
If you are using a local (non-shared) Oracle home, then you must extend the
Oracle RAC database home that is on an existing node (node1 in this procedure)
to a target node (node3 in this procedure).
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems 11-1
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Navigate to the Oracle_home/addnode directory on node1 and run the
addnode.sh script.
If you want to perform a silent installation, run the addnode.sh script using the
following syntax:
$ ./addnode.sh -silent "CLUSTER_NEW_NODES={node3}"
•
If you have a shared Oracle home that is shared using Oracle Automatic Storage
Management Cluster File System (Oracle ACFS), then do the following to extend
the Oracle database home to node3:
1.
Start the Oracle ACFS resource on the new node by running the following
command as root from the Grid_home/bin directory:
# srvctl start filesystem -device volume_device [-node node_name]
Note:
Make sure the Oracle ACFS resources, including Oracle ACFS registry
resource and Oracle ACFS file system resource where the Oracle home is
located, are online on the newly added node.
2.
Run the following command as the user that installed Oracle RAC from the
Oracle_home/oui/bin directory on the node you are adding to add the
Oracle RAC database home:
$ ./runInstaller -attachHome ORACLE_HOME="ORACLE_HOME"
"CLUSTER_NODES={node3}"
LOCAL_NODE="node3" ORACLE_HOME_NAME="home_name" -cfs
3.
Navigate to the Oracle_home/addnode directory on node1 and run the
addnode.sh script as the user that installed Oracle RAC using the following
syntax:
$ ./addnode.sh -noCopy "CLUSTER_NEW_NODES={node3}"
Note:
Use the -noCopy option because the Oracle home on the destination node is
already fully populated with software.
•
If you have a shared Oracle home on a shared file system that is not Oracle ACFS,
then you must first create a mount point for the Oracle RAC database home on the
target node, mount and attach the Oracle RAC database home, and update the
Oracle Inventory, as follows:
1.
Run the srvctl config database -db db_name command on an
existing node in the cluster to obtain the mount point information.
2.
Run the following command as root on node3 to create the mount point:
# mkdir -p mount_point_path
3.
Mount the file system that hosts the Oracle RAC database home.
11-2 Oracle Real Application Clusters Administration and Deployment Guide
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
4.
Run the following command as the user that installed Oracle RAC from the
Oracle_home/oui/bin directory on the node you are adding to add the
Oracle RAC database home:
$ ./runInstaller -attachHome ORACLE_HOME="ORACLE_HOME" "CLUSTER_NODES=
{local_node_name}" LOCAL_NODE="node_name" ORACLE_HOME_NAME="home_name"
5.
Update the Oracle Inventory as the user that installed Oracle RAC, as follows:
$ ./runInstaller -updateNodeList ORACLE_HOME=mount_point_path
"CLUSTER_NODES=
{node_list}"
In the preceding command, node_list refers to a list of all nodes where the
Oracle RAC database home is installed, including the node you are adding.
Run the Oracle_home/root.sh script on node3 as root.
Note:
Oracle recommends that you back up the OCR after you complete the node
addition process.
You can now add an Oracle RAC database instance to the target node using either of
the procedures in the following sections.
•
Adding Policy-Managed Oracle RAC Database Instances to Target Nodes
•
Adding Administrator-Managed Oracle RAC Database Instances to Target Nodes
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Adding Policy-Managed Oracle RAC Database Instances to Target Nodes
You must manually add undo and redo logs, unless you store your policy-managed
database on Oracle Automatic Storage Management (Oracle ASM) and Oracle
Managed Files is enabled.
If there is space in a server pool to add a node and the database has been started at
least once, then Oracle Clusterware adds the Oracle RAC database instance to the
newly added node and no further action is necessary.
Note:
The database must have been started at least once before you can add the
database instance to the newly added node.
If there is no space in any server pool, then the newly added node moves into the Free
server pool. Use the srvctl modify srvpool command to increase the cardinality
of a server pool to accommodate the newly added node, after which the node moves
out of the Free server pool and into the modified server pool, and Oracle Clusterware
adds the Oracle RAC database instance to the node.
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems 11-3
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Adding Administrator-Managed Oracle RAC Database Instances to Target Nodes
Note:
The procedures in this section only apply to administrator-managed
databases. Policy-managed databases use nodes when the nodes are available
in the database’s server pool.
You can use either Oracle Enterprise Manager or DBCA to add Oracle RAC database
instances to the target nodes. To add a database instance to a target node with Oracle
Enterprise Manager, see the Oracle Database 2 Day + Real Application Clusters Guide for
complete information.
This section describes using DBCA to add Oracle RAC database instances.
These tools guide you through the following tasks:
•
Creating a new database instance on each target node
•
Creating and configuring high availability components
•
Creating the Oracle Net configuration for a non-default listener from the Oracle
home
•
Starting the new instance
•
Creating and starting services if you entered services information on the Services
Configuration page
After adding the instances to the target nodes, you should perform any necessary
service configuration procedures, as described in "Workload Management with
Dynamic Database Services".
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Using DBCA in Interactive Mode to Add Database Instances to Target Nodes
To add a database instance to a target node with DBCA in interactive mode, perform
the following steps:
1.
Ensure that your existing nodes have the $ORACLE_HOME environment variable
set to the Oracle RAC home.
2.
Start DBCA by entering dbca at the system prompt from the Oracle_home/bin
directory.
DBCA performs certain CVU checks while running. However, you can also run
CVU from the command line to perform various verifications.
DBCA displays the Welcome page for Oracle RAC. Click Help on any DBCA page
for additional information.
11-4 Oracle Real Application Clusters Administration and Deployment Guide
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
3.
Select Instance Management, click Next, and DBCA displays the Instance
Management page.
4.
Select Add Instance and click Next. DBCA displays the List of Cluster Databases
page that shows the databases and their current status, such as ACTIVE or
INACTIVE.
5.
From the List of Cluster Databases page, select the active Oracle RAC database to
which you want to add an instance. Click Next and DBCA displays the List of
Cluster Database Instances page showing the names of the existing instances for
the Oracle RAC database that you selected.
6.
Click Next to add a new instance and DBCA displays the Adding an Instance
page.
7.
On the Adding an Instance page, enter the instance name in the field at the top of
this page if the instance name that DBCA provides does not match your existing
instance naming scheme.
8.
Review the information on the Summary dialog and click OK or click Cancel to
end the instance addition operation. DBCA displays a progress dialog showing
DBCA performing the instance addition operation.
9.
After you terminate your DBCA session, run the following command to verify the
administrative privileges on the target node and obtain detailed information
about these privileges where node_list consists of the names of the nodes on
which you added database instances:
cluvfy comp admprv -o db_config -d Oracle_home -n node_list [-verbose]
10. Perform any necessary service configuration procedures, as described in
"Workload Management with Dynamic Database Services".
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Using DBCA in Silent Mode to Add Database Instances to Target Nodes
You can use DBCA in silent mode to add instances to nodes on which you have
extended an Oracle Clusterware home and an Oracle Database home.
Before you run the dbca command, ensure that you have set the ORACLE_HOME
environment variable correctly on the existing nodes. Run DBCA, supplying values for
the variables described in Table 11-1, as follows:
dbca -silent -nodeList node_name -gdbName gdb_name
[-instanceName instance_name -sysDBAUserName sysdba -sysDBAPassword
password]
Table 11-1
Variables in the DBCA Silent Mode Syntax
Variable
Description
node_name
The node on which you want to add (or delete) the instance.
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems 11-5
Deleting Oracle RAC from a Cluster Node
Table 11-1
(Cont.) Variables in the DBCA Silent Mode Syntax
Variable
Description
gdb_name
Global database name.
instance_name
Name of the instance. Provide an instance name only if you want
to override the Oracle naming convention for Oracle RAC instance
names.
sysdba
Name of the Oracle user with SYSDBA privileges.
password
Password for the SYSDBA user.
Perform any necessary service configuration procedures, as described in "Workload
Management with Dynamic Database Services".
Related Topics:
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Deleting Oracle RAC from a Cluster Node
To remove Oracle RAC from a cluster node, you must delete the database instance and
the Oracle RAC software before removing the node from the cluster.
Note:
If there are no database instances on the node you want to delete, then
proceed to "Removing Oracle RAC".
This section includes the following procedures to delete nodes from clusters in an
Oracle RAC environment:
•
Deleting Instances from Oracle RAC Databases
•
Removing Oracle RAC
•
Deleting Nodes from the Cluster
Related Topics:
Removing Oracle RAC
This procedure removes Oracle RAC software from the node you are
deleting from the cluster and updates inventories on the remaining
nodes.
Deleting Instances from Oracle RAC Databases
The procedures for deleting database instances are different for policy-managed and
administrator-managed databases.
11-6 Oracle Real Application Clusters Administration and Deployment Guide
Deleting Oracle RAC from a Cluster Node
Deleting a policy-managed database instance involves reducing the number of servers
in the server pool in which the database instance resides. Deleting an administratormanaged database instance involves using DBCA to delete the database instance.
Deleting Policy-Managed Databases
To delete a policy-managed database, reduce the number of servers in the server pool
in which a database instance resides by relocating the server on which the database
instance resides to another server pool. This effectively removes the instance without
having to remove the Oracle RAC software from the node or the node from the cluster.
For example, you can delete a policy-managed database by running the following
commands on any node in the cluster:
$ srvctl stop instance -db db_unique_name -node node_name
$ srvctl relocate server -servers "server_name_list" -serverpool Free
The first command stops the database instance on a particular node and the second
command moves the node out of its current server pool and into the Free server pool.
Deleting Instances from Administrator-Managed Databases
Note:
Before deleting an instance from an Oracle RAC database using SRVCTL to do
the following:
•
If you have services configured, then relocate the services
•
Modify the services so that each service can run on one of the remaining
instances
•
Ensure that the instance to be removed from an administrator-managed
database is neither a preferred nor an available instance of any service
Related Topics:
Removing Oracle RAC
This procedure removes Oracle RAC software from the node you are
deleting from the cluster and updates inventories on the remaining
nodes.
Administering Services with SRVCTL
When you create a service using SRVCTL, you must start the service
with a separate SRVCTL command.
Using DBCA in Interactive Mode to Delete Instances from Nodes
The procedure in this section explains how to use DBCA in interactive
mode to delete an instance from an Oracle RAC database.
Oracle Database 2 Day + Real Application Clusters Guide
Using DBCA in Interactive Mode to Delete Instances from Nodes
The procedure in this section explains how to use DBCA in interactive mode to delete
an instance from an Oracle RAC database.
To delete an instance using DBCA in interactive mode, perform the following steps:
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems 11-7
Deleting Oracle RAC from a Cluster Node
1.
Start DBCA.
Start DBCA on a node other than the node that hosts the instance that you want to
delete. The database and the instance that you plan to delete should be running
during this step.
2.
On the DBCA Operations page, select Instance Management and click Next.
DBCA displays the Instance Management page.
3.
On the DBCA Instance Management page, select the instance to be deleted, select
Delete Instance, and click Next.
4.
On the List of Cluster Databases page, select the Oracle RAC database from which
to delete the instance, as follows:
a.
On the List of Cluster Database Instances page, DBCA displays the instances
that are associated with the Oracle RAC database that you selected and the
status of each instance. Select the cluster database from which you will delete
the instance.
b.
Click OK on the Confirmation dialog to proceed to delete the instance.
DBCA displays a progress dialog showing that DBCA is deleting the instance.
During this operation, DBCA removes the instance and the instance's Oracle
Net configuration.
Click No and exit DBCA or click Yes to perform another operation. If you
click Yes, then DBCA displays the Operations page.
5.
Verify that the dropped instance's redo thread has been removed by using
SQL*Plus on an existing node to query the GV$LOG view. If the redo thread is not
disabled, then disable the thread. For example:
SQL> ALTER DATABASE DISABLE THREAD 2;
6.
Verify that the instance has been removed from OCR by running the following
command, where db_unique_name is the database unique name for your Oracle
RAC database:
$ srvctl config database -db db_unique_name
7.
If you are deleting more than one node, then repeat these steps to delete the
instances from all the nodes that you are going to delete.
Using DBCA in Silent Mode to Delete Instances from Nodes
You can use DBCA in silent mode to delete a database instance from a node.
Run the following command, where the variables are the same as those shown in
Table 11-1 for the DBCA command to add an instance. Provide a node name only if
you are deleting an instance from a node other than the one on where DBCA is
running as shown in the following example where password is the password:
dbca -silent -deleteInstance [-nodeList node_name] -gdbName gdb_name
-instanceName instance_name [-sysDBAUserName sysdba -sysDBAPassword password]
At this point, you have accomplished the following:
•
Deregistered the selected instance from its associated Oracle Net Services listeners
•
Deleted the selected database instance from the instance's configured node
11-8 Oracle Real Application Clusters Administration and Deployment Guide
Deleting Oracle RAC from a Cluster Node
•
Removed the Oracle Net configuration
•
Deleted the Oracle Flexible Architecture directory structure from the instance's
configured node.
Removing Oracle RAC
This procedure removes Oracle RAC software from the node you are deleting from the
cluster and updates inventories on the remaining nodes.
1.
If there is a listener in the Oracle RAC home on the node you are deleting, then
you must disable and stop it before deleting the Oracle RAC software. Run the
following commands on any node in the cluster, specifying the name of the
listener and the name of the node you are deleting:
$ srvctl disable listener -l listener_name -n name_of_node_to_delete
$ srvctl stop listener -l listener_name -n name_of_node_to_delete
2.
Deinstall the Oracle home—only if the Oracle home is not shared—from the node
that you are deleting by running the following command from the Oracle_home
\deinstall directory:
deinstall -local
Caution:
If the Oracle home is shared, then do not run this command because it will
remove the shared software. Proceed to the next step, instead.
Deleting Nodes from the Cluster
After you delete the database instance and the Oracle RAC software, you can begin the
process of deleting the node from the cluster. You accomplish this by running scripts
on the node you want to delete to remove the Oracle Clusterware installation and then
you run scripts on the remaining nodes to update the node list.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems 11-9
Deleting Oracle RAC from a Cluster Node
11-10 Administration and Deployment Guide
12
Adding and Deleting Oracle RAC from
Nodes on Windows Systems
This chapter describes how to extend an existing Oracle Real Application Clusters
(Oracle RAC) home to other nodes and instances in the cluster, and delete Oracle RAC
from nodes and instances in the cluster. This chapter provides instructions for
Windows systems.
Note:
In this chapter, the entries for Grid_home refer to the full path name for the
Oracle Grid Infrastructure home, and the entries for Oracle_home refer to
substitutes for environment variables for the Oracle home with Oracle RAC.
If your goal is to clone an existing Oracle RAC home to create multiple new Oracle
RAC installations across the cluster, then use the cloning procedures that are described
in "Cloning Oracle RAC to Nodes in a New Cluster".
This chapter includes the following topics:
•
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
•
Deleting Oracle RAC from a Cluster Node
Note:
•
Ensure that you have a current backup of Oracle Cluster Registry (OCR)
before adding or deleting Oracle RAC by running the ocrconfig showbackup command.
•
For all of the add node and delete node procedures, temporary directories
such as %TEMP% or C:\Temp should not be shared directories. If your
temporary directories are shared, then set your temporary environment
variable, such as %TEMP%, to a location on a local node. In addition, use a
directory path that exists on all of the nodes.
Related Topics:
Cloning Oracle RAC to Nodes in a New Cluster
This chapter describes how to clone Oracle Real Application Clusters
(Oracle RAC) database homes on Linux and UNIX systems to nodes in a
new cluster.
Oracle Database 2 Day + Real Application Clusters Guide
Adding and Deleting Oracle RAC from Nodes on Windows Systems 12-1
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Before beginning this procedure, ensure that your existing nodes have the correct path
to the Grid_home and that the Oracle_home environment variables are set correctly.
To add Oracle RAC database instances to nodes that already have Oracle Clusterware
installed, you must extend the Oracle RAC home that is on an existing node (node1 in
this procedure) of the cluster to the target nodes.
1.
Navigate to the Oracle_home\addnode directory on node1 and run the
addnode.bat script using the following syntax, where node2 is the name of the
node you are adding:
addnode.bat "CLUSTER_NEW_NODES={node2}"
To run this command in silent mode:
addNode.bat -silent "CLUSTER_NEW_NODES={node2}"
For the Oracle home directory you use, if an Oracle home user was specified when
the Oracle Database software was installed, then OUI requires the password for
the Oracle home user. OUI checks the wallet (stored in the OCR) for the user and
extracts the password from there. If the user information is not contained in the
wallet, then the addnode.bat script generates an error unless you specify the promptPasswd flag on the command line.
2.
If you store your policy-managed database on Oracle Automatic Storage
Management (Oracle ASM), Oracle Managed Files is enabled, and if there is
space in a server pool for node2, then crsd adds the Oracle RAC database
instance to node2 and no further action is necessary. If Oracle Managed Files is
not enabled, then you must manually add undo and redo logs.
If there is no space in a server pool, then node2 moves into the Free server pool.
Use the srvctl modify srvpool command to increase the cardinality of the
server pool to accommodate node2, after which time node2 moves out of the
Free server pool and into the modified server pool, and crsd adds the Oracle
RAC database instance to node2.
3.
If you have an administrator-managed database, then add a new instance on
node2
If you have a shared Oracle home that is shared using Oracle Automatic Storage
Management Cluster File System (Oracle ACFS), then do the following to extend the
Oracle database home to node2:
1.
Start the Oracle ACFS resource on the new node by running the following
command as root from the Grid_home\bin directory:
$ srvctl start filesystem -device volume_device_name [-node node_name]
Note:
Make sure the Oracle ACFS resources, including Oracle ACFS registry
resource and Oracle ACFS file system resource where the Oracle home is
located, are online on the newly added node.
12-2 Oracle Real Application Clusters Administration and Deployment Guide
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
2.
Run the following command as the user that installed Oracle RAC from the
Oracle_home\oui\bin directory on the node you are adding to add the Oracle
RAC database home:
setup.exe -attachHome ORACLE_HOME="ORACLE_HOME" LOCAL_NODE="node2"
ORACLE_HOME_NAME="home_name" -cfs
3.
Navigate to the Oracle_home\addnode directory on node1 and run the
addnode.bat script as the user that installed Oracle RAC using the following
syntax:
addnode.bat -noCopy "CLUSTER_NEW_NODES={node2}"
Note:
Use the -noCopy option because the Oracle home on the destination node is
already fully populated with software.
If you have a shared Oracle home on a shared file system that is not Oracle ACFS, then
you must first create a mount point for the Oracle RAC database home on the target
node, mount and attach the Oracle RAC database home, and update the Oracle
Inventory, as follows:
1.
Run the srvctl config database -db db_name command on an existing
node in the cluster to obtain the mount point information.
2.
Mount the file system that hosts the Oracle RAC database home.
3.
Run the following command as the user that installed Oracle RAC from the
Oracle_home\oui\bin directory on the node you are adding to add the Oracle
RAC database home:
setup.exe -attachHome ORACLE_HOME="ORACLE_HOME" "CLUSTER_NODES=
local_node_name}" LOCAL_NODE="node_name" ORACLE_HOME_NAME="home_name"
4.
Update the Oracle Inventory as the user that installed Oracle RAC, as follows:
setup.exe -updateNodeList ORACLE_HOME=mount_point_path
"CLUSTER_NODES={node_list}"
In the preceding command, node_list refers to a list of all nodes where the
Oracle RAC database home is installed, including the node you are adding.
Note:
Oracle recommends that you back up your voting disk and Oracle Cluster
Registry (OCR) files after you complete the node addition process.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Adding Administrator-Managed Oracle RAC Database Instances to Target
Nodes
You can use either Oracle Enterprise Manager or DBCA to add Oracle
RAC database instances to the target nodes.
Adding and Deleting Oracle RAC from Nodes on Windows Systems 12-3
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Adding Administrator-Managed Oracle RAC Database Instances to Target Nodes
You can use either Oracle Enterprise Manager or DBCA to add Oracle RAC database
instances to the target nodes.
This section describes using DBCA to add Oracle RAC database instances.
These tools guide you through the following tasks:
•
Creating a new database instance on each target node
•
Creating and configuring high availability components
•
Creating the Oracle Net configuration for a non-default listener from the Oracle
home
•
Starting the new instance
•
Creating and starting services if you entered services information on the Services
Configuration page
After adding the instances to the target nodes, you should perform any necessary
service configuration procedures.
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Using DBCA in Interactive Mode to Add Database Instances to Target Nodes
To add a database instance to a target node using DBCA in interactive mode, perform
the following steps:
1.
Ensure that your existing nodes have the Oracle home environment variable set
correctly.
2.
Start DBCA by entering dbca at the system prompt from the Oracle_home\bin
directory on an existing node.
DBCA performs certain CVU checks while running. However, you can also run
CVU from the command line to perform various verifications.
3.
On the Database Operations page, select Instance Management, click Next, and
DBCA displays the Instance Management page.
4.
Select Add Instance and click Next. DBCA displays the List of Cluster Databases
page that shows the databases and their current status, such as ACTIVE or
INACTIVE.
5.
From the List of Cluster Databases page, select the active Oracle RAC database to
which you want to add an instance. Click Next and DBCA displays the List of
Cluster Database Instances page showing the names of the existing instances for
the Oracle RAC database that you selected.
12-4 Oracle Real Application Clusters Administration and Deployment Guide
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
6.
Click Next to add a new instance and DBCA displays the Adding an Instance
page.
7.
On the Adding an Instance page, enter the instance name in the field at the top of
this page if the instance name that DBCA provides does not match your existing
instance naming scheme. Then select the new node name from the list.
Note:
If you installed the Oracle home with the Oracle Home User option, then
DBCA prompts you for that password on this page.
8.
Review the information on the Summary Page and click Finish to initiate instance
addition operation. DBCA displays a progress dialog showing DBCA performing
the instance addition operation.
Creating the OraMTS Service for Microsoft Transaction Server
Oracle Services for Microsoft Transaction Server (OraMTS) permit Oracle databases to
be used as resource managers in Microsoft application-coordinated transactions.
OraMTS acts as a proxy for the Oracle database to the Microsoft Distributed
Transaction Coordinator (MSDTC). As a result, OraMTS provides client-side
connection pooling and allows client components that leverage Oracle to participate in
promotable and distributed transactions. In addition, OraMTS can operate with Oracle
databases running on any operating system, given that the services themselves are run
on Windows.
On releases earlier than Oracle Database 12c, the OraMTS service was created as part
of a software-only installation. Starting with Oracle Database 12c, you must use a
configuration tool to create this service.
Create the OraMTS service after adding a node or performing a software-only
installation for Oracle RAC, as follows:
1.
Open a command window.
2.
Change directories to %ORACLE_HOME%\bin.
3.
Run the OraMTSCtl utility to create the OraMTS Service, where host_name is a
list of nodes on which the service should be created:
C:\..bin> oramtsctl.exe -new -host host_name
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Services for Microsoft Transaction Server Developer's Guide for Microsoft
Windows
Using DBCA in Silent Mode to Add Database Instances to Target Nodes
Add instances to nodes on which you have extended an Oracle Clusterware home and
an Oracle Database home.
Use DBCA in silent mode with the following syntax:
dbca -silent -addInstance -nodeList node_name -gdbName gdb_name
[-instanceName instance_name -sysDBAUserName sysdba -sysDBAPassword password]
Adding and Deleting Oracle RAC from Nodes on Windows Systems 12-5
Deleting Oracle RAC from a Cluster Node
See Also:
Table 11-1 for definitions of the variables used in the preceding syntax
Perform any necessary service configuration procedures.
Related Topics:
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Deleting Oracle RAC from a Cluster Node
To remove Oracle RAC from a cluster node, you must delete the database instance and
the Oracle RAC software before removing the node from the cluster.
Note:
If there are no database instances on the node you want to delete, then remove
Oracle RAC.
This section includes the following procedures to delete nodes from clusters in an
Oracle RAC environment:
•
Deleting Instances from Oracle RAC Databases
•
Removing Oracle RAC
•
Deleting Nodes from the Cluster
Related Topics:
Removing Oracle RAC
This procedure removes the Oracle RAC software from the node you are
deleting from the cluster and updates inventories on the remaining
nodes.
Deleting Instances from Oracle RAC Databases
The procedures for deleting instances are different for policy-managed and
administrator-managed databases.
Deleting a policy-managed database instance involves reducing the size of the server
pool in which the database instance resides. Deleting an administrator-managed
database instance involves using DBCA to delete the database instance.
Deleting Policy-Managed Databases
To delete a policy-managed database, decrease the size of the server pool in which a
database instance resides. This effectively removes the instance without having to
remove the Oracle RAC software from the node or the node from the cluster.
12-6 Oracle Real Application Clusters Administration and Deployment Guide
Deleting Oracle RAC from a Cluster Node
For example, you can delete a policy-managed database by running the following
commands on any node in the cluster:
$ srvctl stop instance -db db_unique_name -node node_name
$ srvctl relocate server -servers "server_name_list" -serverpool Free
The first command stops on the instance on a particular node and the second
command moves the list of servers out of their current server pool and into the Free
server pool.
Deleting Instances from Administrator-Managed Databases
Note:
Before deleting an instance from an Oracle RAC database using SRVCTL, do
the following:
•
If you have services configured, then relocate the services
•
Modify the services so that each service can run on one of the remaining
instances
•
Ensure that the instance to be removed from an administrator-managed
database is neither a preferred nor an available instance of any service
Related Topics:
Removing Oracle RAC
This procedure removes the Oracle RAC software from the node you are
deleting from the cluster and updates inventories on the remaining
nodes.
Administering Services with SRVCTL
When you create a service using SRVCTL, you must start the service
with a separate SRVCTL command.
Oracle Database 2 Day + Real Application Clusters Guide
Using DBCA in Interactive Mode to Delete Instances from Nodes
To delete an instance using DBCA in interactive mode, perform the following steps:
1.
Verify there is a current backup of OCR.
Run the ocrconfig -showbackup command to ensure there is a valid backup.
2.
Start DBCA.
Start DBCA on a node other than the node that hosts the instance that you want to
delete. The database and the instance that you plan to delete should continue to be
started and running during this step.
3.
On the DBCA Operations page, select Instance Management, click Next, and
DBCA displays the Instance Management page.
4.
On the Instance Management page, select Delete Instance, click Next, and DBCA
displays the List of Cluster Databases page.
Adding and Deleting Oracle RAC from Nodes on Windows Systems 12-7
Deleting Oracle RAC from a Cluster Node
5.
Select an Oracle RAC database from which to delete an instance. Click Next and
DBCA displays the List of Cluster Database Instances page. The List of Cluster
Database Instances page shows the instances that are associated with the Oracle
RAC database that you selected and the status of each instance.
6.
On the List of Cluster Databases page, select the Oracle RAC database from which
to delete the instance, as follows:
a.
On the List of Cluster Database Instances page, DBCA displays the instances
that are associated with the Oracle RAC database that you selected and the
status of each instance. Select the cluster database from which you will delete
the instance. Click Finish.
b.
Click OK on the Confirmation dialog to proceed to delete the instance.
c.
Click OK on the next Confirmation dialog to delete the instance and related
Optimal Flexible Architecture (OFA) directory structure.
DBCA displays a progress dialog showing that DBCA is deleting the instance.
During this operation, DBCA removes the instance and the instance's Oracle
Net configuration.
Click No and exit DBCA or click Yes to perform another operation. If you
click Yes, then DBCA displays the Operations page.
7.
Verify that the dropped instance's redo thread has been removed using SQL*Plus
to query the V$LOG view from an existing instance. If the redo thread is not
disabled, then disable the thread. For example:
SQL> ALTER DATABASE DISABLE THREAD 2;
8.
Verify that the instance has been removed from OCR by running the following
command, where db_unique_name is the name of the database:
srvctl config database -db db_unique_name
9.
If you are deleting more than one node, then repeat these steps to delete the
instances from all the nodes that you are going to delete.
Using DBCA in Silent Mode to Delete Instances from Nodes
You can use DBCA in silent mode to delete a database instance from a node.
Run the following command, where the variables are the same as those shown in
Table 11-1 for the DBCA command to add an instance. Provide a node name only if
you are deleting an instance from a node other than the one on where DBCA is
running as shown in the following example where password is the SYSDBA
password:
dbca -silent -deleteInstance [-nodeList node_name] -gdbName gdb_name
-instanceName instance_name [-sysDBAUserName sysdba] [-sysDBAPassword password]
At this point, you have accomplished the following:
•
Deregistered the selected instance from its associated Oracle Net Services listeners
•
Deleted the selected database instance from the instance's configured node
•
Removed the Oracle Net configuration
12-8 Oracle Real Application Clusters Administration and Deployment Guide
Deleting Oracle RAC from a Cluster Node
•
Deleted the Oracle Flexible Architecture directory structure from the instance's
configured node.
Removing Oracle RAC
This procedure removes the Oracle RAC software from the node you are deleting from
the cluster and updates inventories on the remaining nodes.
1.
If there is a listener in the Oracle RAC home on the node you are deleting, then
you must disable and stop it before deleting the Oracle RAC software. Run the
following commands on any node in the cluster, specifying the name of the
listener and the name of the node you are deleting:
C:\srvctl disable listener -listener listener_name -node name_of_node_to_delete
C:\srvctl stop listener -listener listener_name -node name_of_node_to_delete
2.
Deinstall the Oracle home from the node that you are deleting by running the
following command from the Oracle_home\deinstall directory:
deinstall -local
If you have a shared Oracle RAC home, then append the -cfs option to the command
example in this step and provide a complete path location for the cluster file system.
Deleting Nodes from the Cluster
After you delete the instance, you can begin the process of deleting the node from the
cluster. You accomplish this by running scripts on the node you want to delete to
remove the Oracle Clusterware installation and you run scripts on the remaining
nodes to update the node list.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Grid Infrastructure Installation and Upgrade Guide for Microsoft Windows x64
(64-Bit)
Adding and Deleting Oracle RAC from Nodes on Windows Systems 12-9
Deleting Oracle RAC from a Cluster Node
12-10 Administration and Deployment Guide
13
Design and Deployment Techniques
This chapter briefly describes database design and deployment techniques for Oracle
Real Application Clusters (Oracle RAC) environments. It also describes considerations
for high availability and provides general guidelines for various Oracle RAC
deployments.
This chapter includes the following topics:
•
Deploying Oracle RAC for High Availability
•
General Design Considerations for Oracle RAC
•
General Database Deployment Topics for Oracle RAC
Deploying Oracle RAC for High Availability
Many customers implement Oracle RAC to provide high availability for their Oracle
Database applications. For true high availability, you must make the entire
infrastructure of the application highly available. This requires detailed planning to
ensure there are no single points of failure throughout the infrastructure. Even though
Oracle RAC makes your database highly available, if a critical application becomes
unavailable, then your business can be negatively affected. For example, if you choose
to use the Lightweight Directory Access Protocol (LDAP) for authentication, then you
must make the LDAP server highly available. If the database is up but the users
cannot connect to the database because the LDAP server is not accessible, then the
entire system appears to be down to your users.
This section includes the following topics:
•
About Designing a High Availability System
•
Best Practices for Deploying Oracle RAC in a High Availability Environment
•
Consolidating Multiple Applications in a Database or Multiple Databases in a
Cluster
•
Scalability of Oracle RAC
About Designing a High Availability System
For mission critical systems, you must be able to perform failover and recovery, and
your environment must be resilient to all types of failures.
For mission critical systems, you must be able to perform failover and recovery, and
your environment must be resilient to all types of failures. To reach these goals, start
by defining service level requirements for your business. The requirements should
include definitions of maximum transaction response time and recovery expectations
for failures within the datacenter (such as for node failure) or for disaster recovery (if
the entire data center fails). Typically, the service level objective is a target response
Design and Deployment Techniques 13-1
Deploying Oracle RAC for High Availability
time for work, regardless of failures. Determine the recovery time for each redundant
component. Even though you may have hardware components that are running in an
active/active mode, do not assume that if one component fails the other hardware
components can remain operational while the faulty components are being repaired.
Also, when components are running in active/passive mode, perform regular tests to
validate the failover time. For example, recovery times for storage channels can take
minutes. Ensure that the outage times are within your business' service level
agreements, and where they are not, work with the hardware vendor to tune the
configuration and settings.
When deploying mission critical systems, the testing should include functional testing,
destructive testing, and performance testing. Destructive testing includes the injection
of various faults in the system to test the recovery and to make sure it satisfies the
service level requirements. Destructive testing also allows the creation of operational
procedures for the production system.
To help you design and implement a mission critical or highly available system,
Oracle provides a range of solutions for every organization regardless of size. Small
workgroups and global enterprises alike are able to extend the reach of their critical
business applications. With Oracle and the Internet, applications and their data are
now reliably accessible everywhere, at any time. The Oracle Maximum Availability
Architecture (MAA) is the Oracle best practices blueprint that is based on proven
Oracle high availability technologies and recommendations. The goal of the MAA is to
remove the complexity in designing an optimal high availability architecture.
Related Topics:
Oracle Database High Availability Overview
Oracle Maximum Availability Architecture (MAA)
Best Practices for Deploying Oracle RAC in a High Availability Environment
Applications can take advantage of many Oracle Database, Oracle Clusterware, and
Oracle RAC features and capabilities to minimize or mask any failure in the Oracle
RAC environment. For example, you can:
•
Remove TCP/IP timeout waits by using the VIP address to connect to the
database.
•
Create detailed operational procedures and ensure you have the appropriate
support contracts in place to match defined service levels for all components in
the infrastructure.
•
Take advantage of the Oracle RAC Automatic Workload Management features
such as connect time failover, Fast Connection Failover, Fast Application
Notification, and the Load Balancing Advisory.
•
Place voting disks on separate volume groups to mitigate outages due to slow I/O
throughput. To survive the failure of x voting devices, configure 2x + 1 mirrors.
•
Use Oracle Database Quality of Service Management (Oracle Database QoS
Management) to monitor your system and detect performance bottlenecks.
•
Place OCR with I/O service times in the order of 2 milliseconds (ms) or less.
•
Tune database recovery using the FAST_START_MTTR_TARGET initialization
parameter.
13-2 Oracle Real Application Clusters Administration and Deployment Guide
Deploying Oracle RAC for High Availability
•
Use Oracle Automatic Storage Management (Oracle ASM) to manage database
storage.
•
Ensure that strong change control procedures are in place.
•
Check the surrounding infrastructure for high availability and resiliency, such as
LDAP, NIS, and DNS. These entities affect the availability of your Oracle RAC
database. If possible, perform a local backup procedure routinely.
•
Use Oracle Enterprise Manager to administer your entire Oracle RAC
environment, not just the Oracle RAC database. Use Oracle Enterprise Manager to
create and modify services, and to start and stop the cluster database instances
and the cluster database.
•
Use Recovery Manager (RMAN) to back up, restore, and recover data files, control
files, server parameter files (SPFILEs) and archived redo log files. You can use
RMAN with a media manager to back up files to external storage. You can also
configure parallelism when backing up or recovering Oracle RAC databases. In
Oracle RAC, RMAN channels can be dynamically allocated across all of the Oracle
RAC instances. Channel failover enables failed operations on one node to
continue on another node. You can start RMAN from Oracle Enterprise Manager
Backup Manager or from the command line.
•
If you use sequence numbers, then always use CACHE with the NOORDER option
for optimal performance in sequence number generation. With the CACHE option,
however, you may have gaps in the sequence numbers. If your environment
cannot tolerate sequence number gaps, then use the NOCACHE option or consider
pre-generating the sequence numbers. If your application requires sequence
number ordering but can tolerate gaps, then use CACHE and ORDER to cache and
order sequence numbers in Oracle RAC. If your application requires ordered
sequence numbers without gaps, then use NOCACHE and ORDER. The NOCACHE
and ORDER combination has the most negative effect on performance compared to
other caching and ordering combinations.
Note:
If your environment cannot tolerate sequence number gaps, then consider pregenerating the sequence numbers or use the ORDER and CACHE options.
•
If you use indexes, then consider alternatives, such as reverse key indexes to
optimize index performance. Reverse key indexes are especially helpful if you
have frequent inserts to one side of an index, such as indexes that are based on
insert date.
Related Topics:
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Oracle Database 2 Day + Real Application Clusters Guide
Configuring Recovery Manager and Archiving
Design and Deployment Techniques 13-3
Deploying Oracle RAC for High Availability
Consolidating Multiple Applications in a Database or Multiple Databases in a Cluster
Many people want to consolidate multiple applications in a single database or
consolidate multiple databases in a single cluster. Oracle Clusterware and Oracle RAC
support both types of consolidation.
Creating a cluster with a single pool of storage managed by Oracle ASM provides the
infrastructure to manage multiple databases whether they are single instance
databases or Oracle RAC databases.
Managing Capacity During Consolidation
With Oracle RAC databases, you can adjust the number of instances and which nodes
run instances for a given database, based on workload requirements. Features such as
cluster-managed services allow you to manage multiple workloads on a single
database or across multiple databases.
It is important to properly manage the capacity in the cluster when adding work. The
processes that manage the cluster—including processes both from Oracle Clusterware
and the database—must be able to obtain CPU resources in a timely fashion and must
be given higher priority in the system. Oracle Database Quality of Service
Management (Oracle Database QoS Management) can assist consolidating multiple
applications in a cluster or database by dynamically allocating CPU resources to meet
performance objectives. You can also use cluster configuration policies to manage
resources at the cluster level.
Related Topics:
Oracle Database Quality of Service Management User's Guide
Managing the Global Cache Service Processes During Consolidation
Oracle recommends that the number of real time Global Cache Service Processes
(LMSn) on a server is less than or equal to the number of processors. (Note that this is
the number of recognized CPUs that includes cores. For example, a dual-core CPU is
considered to be two CPUs.) It is important that you load test your system when
adding instances on a node to ensure that you have enough capacity to support the
workload.
If you are consolidating many small databases into a cluster, you may want to reduce
the number of LMSn created by the Oracle RAC instance. By default, Oracle Database
calculates the number of processes based on the number of CPUs it finds on the server.
This calculation may result in more LMSn processes than is needed for the Oracle RAC
instance. One LMS process may be sufficient for up to 4 CPUs.To reduce the number
of LMSn processes, set the GC_SERVER_PROCESSES initialization parameter
minimally to a value of 1. Add a process for every four CPUs needed by the
application. In general, it is better to have few busy LMSn processes. Oracle Database
calculates the number of processes when the instance is started, and you must restart
the instance to change the value.
Using a Database Cloud for Consolidation
A database cloud is a set of databases integrated by the Global Data Services
framework into a single virtual server that offers one or more global services, while
ensuring high performance, availability and optimal utilization of resources.
Global Data Services manages these virtualized resources with minimum
administration overhead, and allows the database cloud to quickly scale to handle
13-4 Oracle Real Application Clusters Administration and Deployment Guide
Deploying Oracle RAC for High Availability
additional client requests. The databases that constitute a cloud can be globally
distributed, and clients can connect to the database cloud by simply specifying a
service name, without needing to know anything about the components and topology
of the cloud.
A database cloud can be comprised of multiple database pools. A database pool is a
set of databases within a database cloud that provide a unique set of global services
and belong to a certain administrative domain. Partitioning of cloud databases into
multiple pools simplifies service management and provides higher security by
allowing each pool to be administered by a different administrator. A database cloud
can span multiple geographic regions. A region is a logical boundary that contains
database clients and servers that are considered to be close to each other. Usually a
region corresponds to a data center, but multiple data centers can be in the same
region if the network latencies between them satisfy the service-level agreements of
the applications accessing these data centers.
Global services enable you to integrate locally and globally distributed, loosely
coupled, heterogeneous databases into a scalable and highly available private
database cloud. This database cloud can be shared by clients around the globe. Using a
private database cloud provides optimal utilization of available resources and
simplifies the provisioning of database services.
Related Topics:
Oracle Database Global Data Services Concepts and Administration Guide
Scalability of Oracle RAC
Oracle RAC provides concurrent, transactionally consistent access to a single copy of
the data from multiple systems. It provides scalability beyond the capacity of a single
server. If your application scales transparently on symmetric multiprocessing (SMP)
servers, then it is realistic to expect the application to scale well on Oracle RAC,
without the need to make changes to the application code.
Traditionally, when a database server runs out of capacity, it is replaced with a new
larger server. As servers grow in capacity, they become more expensive. However, for
Oracle RAC databases, you have alternatives for increasing the capacity:
•
You can migrate applications that traditionally run on large SMP servers to run on
clusters of small servers.
•
You can maintain the investment in the current hardware and add a new server to
the cluster (or create or add a new cluster) to increase the capacity.
Adding servers to a cluster with Oracle Clusterware and Oracle RAC does not require
an outage. As soon as the new instance is started, the application can take advantage
of the extra capacity.
All servers in the cluster must run the same operating system and same version of
Oracle Database but the servers do not have to have the same capacity. With Oracle
RAC, you can build a cluster that fits your needs, whether the cluster is made up of
servers where each server is a two-CPU commodity server or clusters where the
servers have 32 or 64 CPUs in each server. The Oracle parallel execution feature allows
a single SQL statement to be divided up into multiple processes, where each process
completes a subset of work. In an Oracle RAC environment, you can define the
parallel processes to run only on the instance where the user is connected or to run
across multiple instances in the cluster.
Design and Deployment Techniques 13-5
General Design Considerations for Oracle RAC
Related Topics:
Cloning Oracle RAC to Nodes in a New Cluster
This chapter describes how to clone Oracle Real Application Clusters
(Oracle RAC) database homes on Linux and UNIX systems to nodes in a
new cluster.
Using Cloning to Extend Oracle RAC to Nodes in the Same Cluster
Adding and Deleting Oracle RAC from Nodes on Linux and UNIX Systems
Extend an existing Oracle Real Application Clusters (Oracle RAC) home
to other nodes and instances in the cluster, and delete Oracle RAC from
nodes and instances in the cluster.
Adding and Deleting Oracle RAC from Nodes on Windows Systems
General Design Considerations for Oracle RAC
This section briefly describes database design and deployment techniques for Oracle
RAC environments. It also describes considerations for high availability and provides
general guidelines for various Oracle RAC deployments.
Consider performing the following steps during the design and development of
applications that you are deploying on an Oracle RAC database:
1.
Tune the design and the application
2.
Tune the memory and I/O
3.
Tune contention
4.
Tune the operating system
Note:
If an application does not scale on an SMP system, then moving the
application to an Oracle RAC database cannot improve performance.
Consider using hash partitioning for insert-intensive online transaction processing
(OLTP) applications. Hash partitioning:
•
Reduces contention on concurrent inserts into a single database structure
•
Affects sequence-based indexes when indexes are locally partitioned with a table
and tables are partitioned on sequence-based keys
•
Is transparent to the application
If you use hash partitioning for tables and indexes for OLTP environments, then you
can greatly improve performance in your Oracle RAC database. Note that you cannot
use index range scans on an index with hash partitioning.
General Database Deployment Topics for Oracle RAC
This section describes considerations when deploying Oracle RAC databases. Oracle
RAC database performance is not compromised if you do not employ these
13-6 Oracle Real Application Clusters Administration and Deployment Guide
General Database Deployment Topics for Oracle RAC
techniques. If you have an effective noncluster design, then your application will run
well on an Oracle RAC database.
This section includes the following topics:
•
Tablespace Use in Oracle RAC
•
Object Creation and Performance in Oracle RAC
•
Node Addition and Deletion and the SYSAUX Tablespace in Oracle RAC
•
Distributed Transactions and Oracle RAC
•
Deploying OLTP Applications in Oracle RAC
•
Flexible Implementation with Cache Fusion
•
Deploying Data Warehouse Applications with Oracle RAC
•
Data Security Considerations in Oracle RAC
Tablespace Use in Oracle RAC
In addition to using locally managed tablespaces, you can further simplify space
administration by using automatic segment space management (ASSM) and automatic
undo management.
ASSM distributes instance workloads among each instance's subset of blocks for
inserts. This improves Oracle RAC performance because it minimizes block transfers.
To deploy automatic undo management in an Oracle RAC environment, each instance
must have its own undo tablespace.
Object Creation and Performance in Oracle RAC
As a general rule, only use DDL statements for maintenance tasks and avoid executing
DDL statements during peak system operation periods. In most systems, the amount
of new object creation and other DDL statements should be limited. Just as in
noncluster Oracle databases, excessive object creation and deletion can increase
performance overhead.
Node Addition and Deletion and the SYSAUX Tablespace in Oracle RAC
If you add nodes to your Oracle RAC database environment, then you may need to
increase the size of the SYSAUX tablespace. Conversely, if you remove nodes from
your cluster database, then you may be able to reduce the size of your SYSAUX
tablespace.
See Also:
Your platform-specific Oracle RAC installation guide for guidelines about
sizing the SYSAUX tablespace for multiple instances
Distributed Transactions and Oracle RAC
If you are running XA Transactions in an Oracle RAC environment and the
performance is poor, then direct all branches of a tightly coupled distributed
Design and Deployment Techniques 13-7
General Database Deployment Topics for Oracle RAC
transaction to the same instance by creating multiple Oracle Distributed Transaction
Processing (DTP) services, with one or more on each Oracle RAC instance.
Each DTP service is a singleton service that is available on one and only one Oracle
RAC instance. All access to the database server for distributed transaction processing
must be done by way of the DTP services. Ensure that all of the branches of a single
global distributed transaction use the same DTP service. In other words, a network
connection descriptor, such as a TNS name, a JDBC URL, and so on, must use a DTP
service to support distributed transaction processing.
Related Topics:
Distributed Transaction Processing in Oracle RAC
Oracle Database Development Guide
Deploying OLTP Applications in Oracle RAC
Cache Fusion makes Oracle RAC databases the optimal deployment servers for online
transaction processing (OLTP) applications. This is because these types of applications
require:
•
High availability if there are failures
•
Scalability to accommodate increased system demands
•
Load balancing according to demand fluctuations
The high availability features of Oracle Database and Oracle RAC can re-distribute
and load balance workloads to surviving instances without interrupting processing.
Oracle RAC also provides excellent scalability so that if you add or replace a node,
then Oracle Database re-masters resources and re-distributes processing loads.
Flexible Implementation with Cache Fusion
To accommodate the frequently changing workloads of online transaction processing
systems, Oracle RAC remains flexible and dynamic despite changes in system load
and system availability. Oracle RAC addresses a wide range of service levels that, for
example, fluctuate due to:
•
Varying user demands
•
Peak scalability issues like trading storms (bursts of high volumes of transactions)
•
Varying availability of system resources
Deploying Data Warehouse Applications with Oracle RAC
This section discusses how to deploy data warehouse systems in Oracle RAC
environments by briefly describing the data warehouse features available in shared
disk architectures.
This section includes the following topics:
•
Speed-Up for Data Warehouse Applications on Oracle RAC
•
Parallel Execution in Data Warehouse Systems and Oracle RAC
13-8 Oracle Real Application Clusters Administration and Deployment Guide
General Database Deployment Topics for Oracle RAC
Speed-Up for Data Warehouse Applications on Oracle RAC
Oracle RAC is ideal for data warehouse applications because it augments the
noncluster benefits of Oracle Database. Oracle RAC does this by maximizing the
processing available on all of the nodes that belong to an Oracle RAC database to
provide speed-up for data warehouse systems.
The query optimizer considers parallel execution when determining the optimal
execution plans. The default cost model for the query optimizer is CPU+I/O and the
cost unit is time. In Oracle RAC, the query optimizer dynamically computes intelligent
defaults for parallelism based on the number of processors in the nodes of the cluster.
An evaluation of the costs of alternative access paths, table scans versus indexed
access, for example, takes into account the degree of parallelism available for the
operation. This results in Oracle Database selecting the execution plans that are
optimized for your Oracle RAC configuration.
Parallel Execution in Data Warehouse Systems and Oracle RAC
Parallel execution uses multiple processes to run SQL statements on one or more CPUs
and is available on both noncluster Oracle databases and Oracle RAC databases.
Oracle RAC takes full advantage of parallel execution by distributing parallel
processing across all available instances. The number of processes that can participate
in parallel operations depends on the degree of parallelism assigned to each table or
index.
Related Topics:
Oracle Database Performance Tuning Guide
Oracle Database Concepts
Data Security Considerations in Oracle RAC
This section describes the following two Oracle RAC security considerations:
•
Transparent Data Encryption and Keystores
•
Windows Firewall Considerations
Transparent Data Encryption and Keystores
Oracle Database enables Oracle RAC nodes to share the keystore (wallet). This
eliminates the need to manually copy and synchronize the keystore across all nodes.
Oracle recommends that you create the keystore on a shared file system. This allows
all instances to access the same shared keystore.
Oracle RAC uses keystores in the following ways:
1.
Any keystore operation, like opening or closing the keystore, performed on any
one Oracle RAC instance is applicable for all other Oracle RAC instances. This
means that when you open and close the keystore for one instance, then it opens
and closes the keystore for all Oracle RAC instances.
2.
When using a shared file system, ensure that the
ENCRYPTION_WALLET_LOCATION parameter for all Oracle RAC instances points
to the same shared keystore location. The security administrator must also ensure
security of the shared keystore by assigning appropriate directory permissions.
Design and Deployment Techniques 13-9
General Database Deployment Topics for Oracle RAC
Note:
If Oracle Automatic Storage Management Cluster File System (Oracle ACFS)
is available for your operating system, then Oracle recommends that you store
the keystore in Oracle ACFS. If you do not have Oracle ACFS in Oracle ASM,
then use the Oracle ASM Configuration Assistant (ASMCA) to create it. You
must add the mount point to the sqlnet.ora file in each instance, as follows:
ENCRYPTION_WALLET_LOCATION=
(SOURCE = (METHOD = FILE)
(METHOD_DATA =
(DIRECTORY = /opt/oracle/acfsmounts/data_keystore)))
This file system is mounted automatically when the instances start. Opening
and closing the keystore, and commands to set or rekey and rotate the TDE
master encryption key, are synchronized between all nodes.
3.
A master key rekey performed on one instance is applicable for all instances.
When a new Oracle RAC node comes up, it is aware of the current keystore open
or close status.
4.
Do not issue any keystore ADMINISTER KEY MANAGEMENT SET KEYSTORE
OPEN or CLOSE SQL statements while setting up or changing the master key.
Deployments where shared storage does not exist for the keystore require that each
Oracle RAC node maintain a local keystore. After you create and provision a keystore
on a single node, you must copy the keystore and make it available to all of the other
nodes, as follows:
•
For systems using Transparent Data Encryption with encrypted keystores, you
can use any standard file transport protocol, though Oracle recommends using a
secured file transport.
•
For systems using Transparent Data Encryption with auto-login keystores, file
transport through a secured channel is recommended.
To specify the directory in which the keystore must reside, set the or
ENCRYPTION_WALLET_LOCATION parameter in the sqlnet.ora file. The local
copies of the keystore need not be synchronized for the duration of Transparent Data
Encryption usage until the server key is re-keyed though the ADMINISTER KEY
MANAGEMENT SET KEY SQL statement. Each time you issue the ADMINISTER KEY
MANAGEMENT SET KEY statement on a database instance, you must again copy the
keystore residing on that node and make it available to all of the other nodes. Then,
you must close and reopen the keystore on each of the nodes. To avoid unnecessary
administrative overhead, reserve re-keying for exceptional cases where you believe
that the server master key may have been compromised and that not re-keying it
could cause a serious security problem.
Related Topics:
Oracle Database Advanced Security Guide
Windows Firewall Considerations
By default, all installations of Windows Server 2003 Service Pack 1 and higher enable
the Windows Firewall to block virtually all TCP network ports to incoming
connections. As a result, any Oracle products that listen for incoming connections on a
13-10 Oracle Real Application Clusters Administration and Deployment Guide
General Database Deployment Topics for Oracle RAC
TCP port will not receive any of those connection requests, and the clients making
those connections will report errors.
Depending upon which Oracle products you install and how they are used, you may
need to perform additional Windows post-installation configuration tasks so that the
Firewall products are functional on Windows Server 2003.
Related Topics:
Oracle Grid Infrastructure Installation and Upgrade Guide for Microsoft Windows x64
(64-Bit)
Design and Deployment Techniques 13-11
General Database Deployment Topics for Oracle RAC
13-12 Administration and Deployment Guide
14
Monitoring Performance
This chapter describes how to monitor and tune Oracle Real Application Clusters
(Oracle RAC) performance.
This chapter includes the following topics:
•
Overview of Monitoring and Tuning Oracle RAC Databases
•
Verifying the Interconnect Settings for Oracle RAC
•
Influencing Interconnect Processing
•
Performance Views in Oracle RAC
•
Creating Oracle RAC Data Dictionary Views with CATCLUST.SQL
•
Oracle RAC Performance Statistics
•
Automatic Workload Repository in Oracle RAC Environments
•
Active Session History Reports for Oracle RAC
•
Monitoring Oracle RAC Statistics and Wait Events
Overview of Monitoring and Tuning Oracle RAC Databases
This section includes the following topics:
•
Monitoring Oracle RAC and Oracle Clusterware
•
Tuning Oracle RAC Databases
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Oracle Database 2 Day DBA
Oracle Database 2 Day + Performance Tuning Guide
Oracle Clusterware Administration and Deployment Guide
Monitoring Oracle RAC and Oracle Clusterware
Using Oracle Enterprise Manager is the preferred method for monitoring Oracle RAC
and Oracle Clusterware. Oracle Enterprise Manager is an Oracle Web-based integrated
management solution for monitoring and administering your computing
environment. From any location where you can access a web browser, you can
manage Oracle RAC databases, application servers, host computers, and Web
applications, in addition to related hardware and software. For example, you can
Monitoring Performance 14-1
Overview of Monitoring and Tuning Oracle RAC Databases
monitor your Oracle RAC database performance from your office, home, or a remote
site, if you have access to a Web browser.
Oracle Enterprise Manager Cloud Control is cluster-aware and provides a central
console to manage your cluster database. From the Cluster Database Home page, you
can do all of the following:
•
View the overall system status, such as the number of nodes in the cluster and
their current status. This high-level view capability means that you do not have to
access each individual database instance for details if you just want to see
inclusive, aggregated information.
•
View alert messages aggregated across all the instances with lists for the source of
each alert message. An alert message is an indicator that signifies that a particular
metric condition has been encountered. A metric is a unit of measurement used to
report the system's conditions.
•
Review issues that are affecting the entire cluster and those issues that are
affecting individual instances.
•
Monitor cluster cache coherency statistics to help you identify processing trends
and optimize performance for your Oracle RAC environment. Cache coherency
statistics measure how well the data in caches on multiple instances is
synchronized. If the data caches are completely synchronized with each other,
then reading a memory location from the cache on any instance will return the
most recent data written to that location from any cache on any instance.
Oracle Enterprise Manager accumulates data over specified periods of time, called
collection-based data. Oracle Enterprise Manager also provides current data, called
real-time data.
Oracle Database 2 Day + Real Application Clusters Guide provides complete information
about monitoring performance with Oracle Enterprise Manager, including:
•
Automatic Database Diagnostic Monitor and Oracle RAC Performance
•
The Cluster Database Home Page
•
The Interconnects Page
•
The Cluster Database Performance Page
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
The Cluster Database Home Page
You can use Oracle Enterprise Manager with a client browser to monitor the status of
both Oracle Clusterware and the Oracle RAC environments. Monitoring can include
such things as:
•
Notification if there are any VIP relocations
•
Status of the Oracle Clusterware on each node of the cluster using information
obtained through the Cluster Verification Utility (cluvfy)
•
Notification if node applications (nodeapps) start or stop
14-2 Oracle Real Application Clusters Administration and Deployment Guide
Overview of Monitoring and Tuning Oracle RAC Databases
•
Notification of issues in the Oracle Clusterware alert log for OCR, voting disk
issues (if any), and node evictions
The Cluster Database Home page is similar to a noncluster Database Home page.
However, on the Cluster Database Home page, Oracle Enterprise Manager displays
the system state and availability. This includes a summary about alert messages and
job activity, and links to all the database and Oracle Automatic Storage Management
(Oracle ASM) instances. For example, you can track problems with services on the
cluster including when a service is not running on all of the preferred instances or
when a service response time threshold is not being met.
The Interconnects Page
You can use the Oracle Enterprise Manager Interconnects page to monitor the Oracle
Clusterware environment. The Interconnects page shows the public and private
interfaces on the cluster and the load contributed by database instances on the
interconnect, including:
•
Overall throughput across the private interconnect
•
Notification if a database instance is using public interface due to
misconfiguration
•
Throughput and errors (if any) on the interconnect
•
Throughput contributed by individual instances on the interconnect
All of this information is also available as collections that have a historic view, which
is useful with cluster cache coherency, such as when diagnosing problems related to
cluster wait events. You can access the Interconnects page by clicking the Interconnect
tab on the Cluster Database home page or clicking the Interconnect Alerts link under
Diagnostic Findings on the Oracle RAC database home page.
The Cluster Database Performance Page
The Oracle Enterprise Manager Cluster Database Performance page provides a quick
glimpse of the performance statistics for a database.
Statistics are rolled up across all the instances in the cluster database in charts. Using
the links next to the charts, you can get more specific information and perform any of
the following tasks:
•
Identify the causes of performance issues.
•
Decide whether resources need to be added or redistributed.
•
Tune your SQL plan and schema for better optimization.
•
Resolve performance issues
The charts on the Cluster Database Performance page include the following:
•
Chart for Cluster Host Load Average: The Cluster Host Load Average chart in
the Cluster Database Performance page shows potential problems that are outside
the database. The chart shows maximum, average, and minimum load values for
available nodes in the cluster for the previous hour.
•
Chart for Global Cache Block Access Latency: Each cluster database instance has
its own buffer cache in its System Global Area (SGA). Using Cache Fusion, Oracle
RAC environments logically combine each instance's buffer cache to enable the
Monitoring Performance 14-3
Overview of Monitoring and Tuning Oracle RAC Databases
database instances to process data as if the data resided on a logically combined,
single cache.
•
Chart for Average Active Sessions: The Average Active Sessions chart in the
Cluster Database Performance page shows potential problems inside the database.
Categories, called wait classes, show how much of the database is using a
resource, such as CPU or disk I/O. Comparing CPU time to wait time helps to
determine how much of the response time is consumed with useful work rather
than waiting for resources that are potentially held by other processes.
•
Chart for Database Throughput: The Database Throughput charts summarize
any resource contention that appears in the Average Active Sessions chart, and
also show how much work the database is performing on behalf of the users or
applications. The Per Second view shows the number of transactions compared to
the number of logons, and the amount of physical reads compared to the redo size
per second. The Per Transaction view shows the amount of physical reads
compared to the redo size per transaction. Logons is the number of users that are
logged on to the database.
In addition, the Top Activity drill down menu on the Cluster Database Performance
page enables you to see the activity by wait events, services, and instances. Plus, you
can see the details about SQL/sessions by going to a prior point in time by moving the
slider on the chart.
The Cluster Database Performance page provides a quick glimpse of the performance
statistics for an Oracle RAC database. Statistics are rolled up across all of the instances
in the cluster database so that users can identify performance issues without going
through all the instances. To help triage the performance issues related to services,
Oracle Enterprise Manager aggregates the activity data at the following levels:
•
Aggregate by waits
All the activity data is presented in 12 categories: CPU, Scheduler, User I/O,
System I/O, Concurrency, Application, Commit, Configuration, Administrative,
Network, Cluster and Other. The data presented is rolled up from all of the
running instances.
•
Aggregate by services
All the activity data is rolled up for each service. When the activity data is
presented in this way, it is easy to identify which service is most active, and needs
more analysis.
•
Aggregate by instances
As a similar effort, the activity data is rolled up for each instance, if services are
not the interested ones.
The aggregates are provided on the pages where the activity data is presented
including: Database Performance Page, Top Activity Page, Wait Details Page and
Service Details Page.
Related Topics:
Oracle Database 2 Day + Real Application Clusters Guide
Tuning Oracle RAC Databases
All noncluster tuning practices for Oracle Database apply to Oracle RAC databases.
14-4 Oracle Real Application Clusters Administration and Deployment Guide
Verifying the Interconnect Settings for Oracle RAC
Related Topics:
Oracle Database 2 Day + Performance Tuning Guide
Oracle Database Performance Tuning Guide
Verifying the Interconnect Settings for Oracle RAC
Use SQL statements to verify the interconnect settings for Oracle RAC.
The interconnect and internode communication protocols can affect Cache Fusion
performance. In addition, the interconnect bandwidth, its latency, and the efficiency of
the IPC protocol determine the speed with which Cache Fusion processes block
transfers.
To verify the interconnect settings of the Oracle RAC database instance to which you
are connected, query the V$CLUSTER_INTERCONNECTS and V
$CONFIGURED_INTERCONNECTS views. For example:
Example 14-1
Verify Interconnect Settings with V$CLUSTER_INTERCONNECTS
SQL> SELECT * FROM V$CLUSTER_INTERCONNECTS;
NAME
IP_ADDRESS
--------------- -------------eth2
10.137.20.181
IS_PUBLIC SOURCE
--------------------------------NO
Oracle Cluster Repository
Note:
You can query the GV$CLUSTER_INTERCONNECTS view to display the entries
for all of the instances in the cluster.
Example 14-2 Verify Interconnect Settings with V
$CONFIGURED_INTERCONNECTS
SQL> SELECT * FROM V$CONFIGURED_INTERCONNECTS;
NAME
--------------eth2
eth0
IP_ADDRESS
--------------10.137.20.181
10.137.8.225
IS_PUBLIC
--NO
YES
SOURCE
------------------------------Oracle Cluster Repository
Oracle Cluster Repository
Influencing Interconnect Processing
Once your interconnect is operative, you cannot significantly influence its
performance. However, you can influence an interconnect protocol's efficiency by
adjusting the interprocess communication (IPC) buffer sizes.
The Oracle Cluster Registry (OCR) stores your system's interconnect information. Use
the Oracle Interface Configuration (OIFCFG) command-line utility oifcfg getif
command or the OCRDUMP utility to identify the interconnect that you are using.
You can then change the interconnect that you are using by running an OIFCFG
command.
Although you rarely need to set the CLUSTER_INTERCONNECTS parameter, you can
use it to assign a private network IP address or NIC as in the following example:
CLUSTER_INTERCONNECTS=10.0.0.1
Monitoring Performance 14-5
Performance Views in Oracle RAC
If you are using an operating system-specific vendor IPC protocol, then the trace
information may not reveal the IP address.
Notes:
•
You can also use OIFCFG command to assign private network or private
IP addresses.
•
If your cluster has Oracle Clusterware 12c release 2 (12.2) or later
installed, then you can assign either IPv4 or IPv6 addresses to multiple
private networks. You must choose one or the other protocol and use that
protocol for all of the private networks in the cluster.
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Oracle Clusterware Administration and Deployment Guide
Oracle Database Reference
Performance Views in Oracle RAC
Each instance has a set of instance-specific views, which are prefixed with V$.
You can also query global dynamic performance views to retrieve performance
information from all of the qualified instances. Global dynamic performance view
names are prefixed with GV$.
Querying a GV$ view retrieves the V$ view information from all qualified instances. In
addition to the V$ information, each GV$ view contains an extra column named
INST_ID of data type NUMBER. The INST_ID column displays the instance number
from which the associated V$ view information was obtained.
You can use the INST_ID column as a filter to retrieve V$ information from a subset
of available instances. For example, the following query retrieves the information from
the V$LOCK view for instances 2 and 5:
SQL> SELECT * FROM GV$LOCK WHERE INST_ID = 2 OR INST_ID = 5;
Related Topics:
Oracle Database Reference
Creating Oracle RAC Data Dictionary Views with CATCLUST.SQL
If you did not create your Oracle RAC database with the Database Configuration
Assistant (DBCA), then you must run the CATCLUST.SQL script to create views and
tables related to Oracle RAC. You must have SYSDBA privileges to run this script.
Related Topics:
Oracle Real Application Clusters Installation Guide
14-6 Oracle Real Application Clusters Administration and Deployment Guide
Oracle RAC Performance Statistics
Oracle RAC Performance Statistics
Oracle RAC statistics appear as message request counters or as timed statistics.
Message request counters include statistics showing the number of certain types of
block mode conversions. Timed statistics reveal the total or average time waited for
read and write I/O for particular types of operations.
Automatic Workload Repository in Oracle RAC Environments
You can use Automatic Workload Repository to monitor performance statistics related
to Oracle RAC databases.
Automatic Workload Repository (AWR) automatically generates snapshots of the
performance data once every hour and collects the statistics in the workload
repository. In Oracle RAC environments, each AWR snapshot captures data from all
active instances in the cluster. The data for each snapshot set is captured from the
same point in time. AWR stores the snapshot data for all instances in the same table
and the data is identified by an instance qualifier. For example, the
BUFFER_BUSY_WAIT statistic shows the number of buffer waits on each instance.
AWR does not store data that is aggregated from across the entire cluster. In other
words, the data is stored for each individual instance.
Using the Automatic Database Diagnostic Monitor (ADDM), you can analyze the
information collected by AWR for possible performance problems with Oracle
Database. ADDM presents performance data from a cluster-wide perspective, thus
enabling you to analyze performance on a global basis. In an Oracle RAC
environment, ADDM can analyze performance using data collected from all instances
and present it at different levels of granularity, including:
•
Analysis for the entire cluster
•
Analysis for a specific database instance
•
Analysis for a subset of database instances
To perform these analyses, you can run the ADDM Advisor in ADDM for Oracle RAC
mode to perform an analysis of the entire cluster; in Local ADDM mode to analyze the
performance of an individual instance; or in Partial ADDM mode to analyze a subset
of instances. Activate ADDM analysis using the advisor framework through Advisor
Central in Oracle Enterprise Manager, or through the DBMS_ADVISOR and
DBMS_ADDM PL/SQL packages.
Related Topics:
Oracle Database Performance Tuning Guide
Oracle Database PL/SQL Packages and Types Reference
Active Session History Reports for Oracle RAC
This section describes Active Session History (ASH) reports for Oracle RAC under the
following topics:
•
Overview of ASH Reports for Oracle RAC
•
ASH Report for Oracle RAC: Top Cluster Events
•
ASH Report for Oracle RAC: Top Remote Instance
Monitoring Performance 14-7
Monitoring Oracle RAC Statistics and Wait Events
Related Topics:
Oracle Database Performance Tuning Guide
Overview of ASH Reports for Oracle RAC
ASH is an integral part of the Oracle Database self-management framework and is
useful for diagnosing performance problems in Oracle RAC environments. ASH
report statistics provide details about Oracle Database session activity. Oracle
Database records information about active sessions for all active Oracle RAC instances
and stores this data in the System Global Area (SGA). Any session that is connected to
the database and using CPU is considered an active session. The exception to this is
sessions that are waiting for an event that belongs to the idle wait class.
ASH reports present a manageable set of data by capturing only information about
active sessions. The amount of the data is directly related to the work being
performed, rather than the number of sessions allowed on the system.
ASH statistics that are gathered over a specified duration can be put into ASH reports.
Each ASH report is divided into multiple sections to help you identify short-lived
performance problems that do not appear in the ADDM analysis. Two ASH report
sections that are specific to Oracle RAC are Top Cluster Events and Top Remote
Instance as described in the next two sections.
ASH Report for Oracle RAC: Top Cluster Events
The ASH report Top Cluster Events section is part of the Top Events report that is
specific to Oracle RAC. The Top Cluster Events report lists events that account for the
highest percentage of session activity in the cluster wait class event along with the
instance number of the affected instances. You can use this information to identify
which events and instances caused a high percentage of cluster wait events.
ASH Report for Oracle RAC: Top Remote Instance
The ASH report Top Remote Instance section is part of the Top Load Profile report
that is specific to Oracle RAC. The Top Remote Instance report shows cluster wait
events along with the instance numbers of the instances that accounted for the highest
percentages of session activity. You can use this information to identify the instance
that caused the extended cluster wait period.
Monitoring Oracle RAC Statistics and Wait Events
This section explains wait events and statistics specific to Oracle RAC and how to
interpret them when assessing performance data generated by the Automatic
Workload Repository (AWR), Statspack, or by ad-hoc queries of the dynamic
performance views.
This section includes the following topics:
•
Oracle RAC Statistics and Events in AWR and Statspack Reports
•
Oracle RAC Wait Events
•
Monitoring Performance by Analyzing GCS and GES Statistics
•
Analyzing Cache Fusion Transfer Impact Using GCS Statistics
•
Analyzing Response Times Based on Wait Events
14-8 Oracle Real Application Clusters Administration and Deployment Guide
Monitoring Oracle RAC Statistics and Wait Events
Related Topics:
Oracle Database Performance Tuning Guide
Oracle Streams Concepts and Administration
Oracle RAC Statistics and Events in AWR and Statspack Reports
The statistics snapshots generated by AWR and Statspack can be evaluated by
producing reports displaying summary data such as load and cluster profiles based on
regular statistics and wait events gathered on each instance.
Most of the relevant data is summarized on the Oracle RAC Statistics Page. This
information includes:
•
Global cache load profile
•
Global cache efficiency percentages—workload characteristics
•
Global cache and Enqueue Service (GES)—messaging statistics
Additional Oracle RAC sections appear later in the report:
•
Global enqueue statistics
•
Global CR statistics
•
Global CURRENT served statistics
•
Global cache transfer statistics.
Oracle RAC Wait Events
Analyzing and interpreting what causes sessions to wait is an important method to
determine where time is spent.
In Oracle RAC, the wait time is attributed to an event which reflects the exact outcome
of a request. For example, when a session on an instance is looking for a block in the
global cache, it does not know whether it will receive the data cached by another
instance or whether it will receive a message to read from disk. The wait events for the
global cache convey precise information and waiting for global cache blocks or
messages is:
•
Summarized in a broader category called Cluster Wait Class
•
Temporarily represented by a placeholder event which is active while waiting for
a block, for example:
•
–
gc current block request
–
gc cr block request
Attributed to precise events when the outcome of the request is known, for
example:
–
gc current block 3-way
–
gc current block busy
–
gc cr block grant 2-way
Monitoring Performance 14-9
Monitoring Oracle RAC Statistics and Wait Events
In summary, the wait events for Oracle RAC convey information valuable for
performance analysis. They are used in Automatic Database Diagnostic Monitor
(ADDM) to enable precise diagnostics of the effect of cache fusion.
Monitoring Performance by Analyzing GCS and GES Statistics
To determine the amount of work and cost related to inter-instance messaging and
contention, examine block transfer rates, remote requests made by each transaction,
the number and time waited for global cache events as described under the following
headings:
•
Analyzing the Effect of Cache Fusion in Oracle RAC
•
Analyzing Performance Using GCS and GES Statistics
Analyzing the Effect of Cache Fusion in Oracle RAC
The effect of accessing blocks in the global cache and maintaining coherency is
represented by:
•
The Global Cache Service (GCS) statistics for current and cr blocks, for
example, gc current blocks received, gc cr blocks received, and so
on
•
The GCS wait events, for gc current block 3-way, gc cr grant 2-way,
and so on
The response time for cache fusion transfers is determined by the messaging and
processing times imposed by the physical interconnect components, the IPC protocol
and the GCS protocol. It is not affected by disk I/O factors other than occasional log
writes. The cache fusion protocol does not require I/O to data files to guarantee cache
coherency and Oracle RAC inherently does not cause any more I/O to disk than a
nonclustered instance.
Analyzing Performance Using GCS and GES Statistics
You can monitor GCS performance by identifying data blocks and objects which are
frequently used (hot) by all instances.
High concurrency on certain blocks may be identified by GCS wait events and times.
The gc current block busy wait event indicates that the access to cached data
blocks was delayed because they were busy either in the remote or the local cache.
This could be caused by any of the following:
•
The blocks were pinned
•
The blocks were held up by sessions
•
The blocks were delayed by a log write on a remote instance
•
A session on the same instance was already accessing a block which was in
transition between instances and the current session needed to wait behind it (for
example, gc current block busy)
Use the V$SESSION_WAIT view to identify objects and data blocks with contention.
The GCS wait events contain the file and block number for a block request in p1 and
p2, respectively.
14-10 Oracle Real Application Clusters Administration and Deployment Guide
Monitoring Oracle RAC Statistics and Wait Events
An additional segment statistic, gc buffer busy, has been added to quickly
determine the busy objects without having to query the V$SESSION_WAIT view
mentioned earlier.
The AWR infrastructure provides a view of active session history which can also be
used to trace recent wait events and their arguments. It is therefore useful for hot
block analysis. Most of the reporting facilities used by AWR and Statspack contain the
object statistics and cluster wait class category, so that sampling of the views
mentioned earlier is largely unnecessary.
Note:
Oracle recommends using ADDM and AWR. However, Statspack is available
for backward compatibility. Statspack provides reporting only. You must run
Statspack at level 7 to collect statistics related to block contention and segment
block waits.
It is advisable to run ADDM on the snapshot data collected by the AWR infrastructure
to obtain an overall evaluation of the impact of the global cache. The advisory will also
identify the busy objects and SQL highest cluster wait time.
Analyzing Cache Fusion Transfer Impact Using GCS Statistics
Describes how to monitor GCS performance by identifying objects read and modified
frequently and the service times imposed by the remote access.
Waiting for blocks to arrive may constitute a significant portion of the response time,
in the same way that reading from disk could increase the block access delays, only
that cache fusion transfers are usually faster than disk access latencies.
The following wait events indicate that the remotely cached blocks were shipped to
the local instance without having been busy, pinned or requiring a log flush:
•
gc current block 2-way
•
gc current block 3-way
•
gc cr block 2-way
•
gc cr block 3-way
The object statistics for gc current blocks received and gc cr blocks
received enable quick identification of the indexes and tables which are shared by
the active instances. As mentioned earlier, creating an ADDM analysis will usually
point you to the SQL statements and database objects that could be impacted by interinstance contention.
Any increases in the average wait times for the events mentioned in the preceding list
could be caused by the following occurrences:
•
High load: CPU shortages, long run queues, scheduling delays
•
Misconfiguration: using public instead of private interconnect for message and
block traffic
If the average wait times are acceptable and no interconnect or load issues can be
diagnosed, then the accumulated time waited can usually be attributed to a few SQL
statements which need to be tuned to minimize the number of blocks accessed.
Monitoring Performance 14-11
Monitoring Oracle RAC Statistics and Wait Events
The column CLUSTER_WAIT_TIME in V$SQLAREA represents the wait time incurred
by individual SQL statements for global cache events and will identify the SQL which
may need to be tuned.
Analyzing Response Times Based on Wait Events
Most global cache wait events that show a high total time as reported in the AWR and
Statspack reports or in the dynamic performance views are normal and may present
themselves as the top database time consumers without actually indicating a problem.
This section describes frequent wait events that you should be aware of when
interpreting performance data.
If user response times increase and a high proportion of time waited is for global
cache, then you should determine the cause. Most reports include a breakdown of
events sorted by percentage of the total time.
It is useful to start with an ADDM report, which analyzes the routinely collected
performance statistics with respect to their impact, and points to the objects and SQL
contributing most to the time waited, and then moves on to the more detailed reports
produced by AWR and Statspack.
Wait events for Oracle RAC include the following categories:
•
Block-Related Wait Events
•
Message-Related Wait Events
•
Contention-Related Wait Events
•
Load-Related Wait Events
Block-Related Wait Events
The main wait events for block-related waits are:
•
gc current block 2-way
•
gc current block 3-way
•
gc cr block 2-way
•
gc cr block 3-way
The block-related wait event statistics indicate that a block was received as either the
result of a 2-way or a 3-way message, that is, the block was sent from either the
resource master requiring 1 message and 1 transfer, or was forwarded to a third node
from which it was sent, requiring 2 messages and 1 block transfer.
Message-Related Wait Events
The main wait events for message-related waits are:
•
gc current grant 2-way
•
gc cr grant 2-way
The message-related wait event statistics indicate that no block was received because it
was not cached in any instance. Instead a global grant was given, enabling the
requesting instance to read the block from disk or modify it.
14-12 Oracle Real Application Clusters Administration and Deployment Guide
Monitoring Oracle RAC Statistics and Wait Events
If the time consumed by these events is high, then it may be assumed that the
frequently used SQL causes a lot of disk I/O (in the event of the cr grant) or that
the workload inserts a lot of data and needs to find and format new blocks frequently
(in the event of the current grant).
Contention-Related Wait Events
The main wait events for contention-related waits are:
•
gc current block busy
•
gc cr block busy
•
gc buffer busy acquire/release
The contention-related wait event statistics indicate that a block was received which
was pinned by a session on another node, was deferred because a change had not yet
been flushed to disk or because of high concurrency, and therefore could not be
shipped immediately. A buffer may also be busy locally when a session has already
initiated a cache fusion operation and is waiting for its completion when another
session on the same node is trying to read or modify the same data. High service times
for blocks exchanged in the global cache may exacerbate the contention, which can be
caused by frequent concurrent read and write accesses to the same data.
The gc current block busy and gc cr block busy wait events indicate that
the local instance that is making the request did not immediately receive a current or
consistent read block. The term busy in these events' names indicates that the sending
of the block was delayed on a remote instance. For example, a block cannot be shipped
immediately if Oracle Database has not yet written the redo for the block's changes to
a log file.
In comparison to block busy wait events, a gc buffer busy event indicates that
Oracle Database cannot immediately grant access to data that is stored in the local
buffer cache. This is because a global operation on the buffer is pending and the
operation has not yet completed. In other words, the buffer is busy and all other
processes that are attempting to access the local buffer must wait to complete.
The existence of gc buffer busy events also means that there is block contention
that is resulting in multiple requests for access to the local block. Oracle Database must
queue these requests. The length of time that Oracle Database needs to process the
queue depends on the remaining service time for the block. The service time is affected
by the processing time that any network latency adds, the processing time on the
remote and local instances, and the length of the wait queue.
The average wait time and the total wait time should be considered when being
alerted to performance issues where these particular waits have a high impact.
Usually, either interconnect or load issues or SQL execution against a large shared
working set can be found to be the root cause.
Load-Related Wait Events
The main wait events for load-related waits are:
•
gc current block congested
•
gc cr block congested
The load-related wait events indicate that a delay in processing has occurred in the
GCS, which is usually caused by high load, CPU saturation and would have to be
solved by additional CPUs, load-balancing, off loading processing to different times or
Monitoring Performance 14-13
Monitoring Oracle RAC Statistics and Wait Events
a new cluster node.For the events mentioned, the wait time encompasses the entire
round trip from the time a session starts to wait after initiating a block request until
the block arrives.
14-14 Oracle Real Application Clusters Administration and Deployment Guide
15
Converting Single-Instance Oracle
Databases to Oracle RAC and Oracle RAC
One Node
Procedures for converting from Oracle Database single-instance databases to Oracle
Real Application Clusters (Oracle RAC) and Oracle RAC One Node databases.
The procedures in this chapter assume that your original single-instance database and
the target Oracle RAC database are using the same release and running on the same
platform. If you are upgrading from an earlier version of Oracle RAC to Oracle RAC
12c, then use Oracle Database Upgrade Assistant (DBUA).
This chapter includes the following topics:
•
Administrative Issues for Converting Databases to Oracle RAC
•
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
•
Preparing to Convert with rconfig and Oracle Enterprise Manager
•
Converting Databases to Oracle RAC Using rconfig
•
Example of rconfig XML Input Files for ConvertToRAC
•
Postconversion Steps
Note:
You must use clustered Oracle Automatic Storage Management (Oracle ASM)
instances for Oracle RAC databases.
Related Topics:
Oracle Database Licensing Information
Administrative Issues for Converting Databases to Oracle RAC
Note the following administrative considerations before converting single-instance
databases to Oracle RAC:
•
Backup procedures should be available before converting from a single-instance
Oracle Database to Oracle RAC. This includes taking a backup of your existing
database before converting to Oracle RAC and being prepared to backup your
Oracle RAC database immediately following the conversion.
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-1
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
•
For archiving with Oracle RAC environments, the archive file format requires a
thread number.
•
The archived logs from all instances of an Oracle RAC database are required for
media recovery. Because of this requirement, if you archive to a file and you do
not use a cluster file system, or some other means to provide shared file systems,
then you require a method of accessing the archive logs from all nodes on which
the cluster database has instances.
•
By default, all database files are migrated to Oracle Managed Files. This feature
simplifies tablespace creation, ensures data file location consistency and
compliance with Oracle Flexible Architecture rules, and reduces human error with
data file management.
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
You can use Database Configuration Assistant (DBCA) to convert from single-instance
Oracle databases to Oracle RAC or Oracle RAC One Node databases.
DBCA automates the configuration of the control file attributes, creates the undo
tablespaces and the redo logs, and creates the initialization parameter file entries for
cluster-enabled environments. DBCA also configures Oracle Net Services, Oracle
Clusterware resources, and the configuration for Oracle RAC database management
using Oracle Enterprise Manager or the Server Control utility (SRVCTL).
Before you use DBCA to convert a single-instance database to an Oracle RAC or an
Oracle RAC One Node database, ensure that your system meets the following
conditions:
•
Your system uses supported hardware and operating system software. Your
system is configured properly to support an Oracle RAC database.
•
The nodes have access to shared storage; for example, either Oracle Cluster File
System or Oracle ASM is available and accessible from all nodes. On Linux on
POWER systems, ensure that GPFS is available and accessible from all nodes.
•
Your applications have no design characteristics that preclude their use with
cluster database processing.
If your platform supports a cluster file system, then you can use it for Oracle RAC.
You can also convert to Oracle RAC and use a non-shared file system. In either case,
Oracle strongly recommends that you use Oracle Universal Installer to install Oracle
Database 12c, which sets up the Oracle home and inventory in an identical location on
each of the selected nodes in your cluster.
This section includes the following topics:
•
Converting Oracle Database Installations to Oracle RAC Using DBCA
•
Converting Single Instance on a Cluster to Oracle RAC One Node Using DBCA
•
Converting Single Instance on a Cluster to Oracle RAC Using DBCA
Related Topics:
Converting Databases
15-2 Oracle Real Application Clusters Administration and Deployment Guide
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
Converting Oracle Database Installations to Oracle RAC Using DBCA
To convert from a single-instance Oracle Database that is on a non-clustered computer
to Oracle RAC, perform the procedures described in the following sections, and in the
order shown:
•
Use DBCA to Create an Image of the Single-Instance Database
•
Complete the Oracle Clusterware Installation
•
Validate the Cluster
•
Copy the Preconfigured Database Image
•
Install Oracle Database 12c Software with Oracle RAC
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance database by using
the following procedure:
1.
Navigate to the bin directory in $ORACLE_HOME, and start DBCA.
2.
At the Welcome page, click Next.
3.
On the Operations page, select Manage Templates, and click Next.
4.
On the Template Management page, select Create a database template and From
an existing database (structure as well as data), then click Next.
5.
On the Source Database page, select the database name in the Database instance
list, and click Next.
6.
Use SQL to ensure that all pluggable databases (PDBs) are open, as follows:
SQL> SELECT name, open_mode FROM v$pdbs;
If any of the PDBs are in a state other than OPEN, then open them using SQL.
7.
On the Template Properties page, enter a name for your template in the Name
field. Oracle recommends that you use the database name.
By default, the template files are generated in the directory $ORACLE_HOME/
assistants/dbca/templates. You can enter a description of the file in the
Description field, and change the template file location in the Template data file
field.
When you have completed the entries, click Next.
8.
On the Location of Database Related Files page, select Maintain the file locations,
so that you can restore the database to the current directory structure, and click
Finish.
DBCA generates two files: a database structure file (template_name.dbc), and a
database preconfigured image file (template_name.dfb).
Complete the Oracle Clusterware Installation
Complete the installation of Oracle Clusterware.
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-3
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
Related Topics:
Oracle Grid Infrastructure Installation and Upgrade Guide
Validate the Cluster
Validate the cluster configuration using Cluster Verification Utility (CVU).
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Copy the Preconfigured Database Image
Copy the preconfigured database image. This includes copying the database structure
*.dbc file and the database preconfigured image *.dfb file (that you used DBCA to
create in a previous section) to a temporary location on the node in the cluster from
which you plan to run DBCA.
Related Topics:
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance
database by using the following procedure:
Install Oracle Database 12c Software with Oracle RAC
1.
Run Oracle Universal Installer to install an Oracle Database with Oracle RAC.
2.
Select Cluster Installation Mode on the Specify Hardware Cluster Installation
page of Oracle Universal Installer, and select the nodes to include in your Oracle
RAC database.
3.
On the Oracle Universal Installer Database Configuration Types page, select the
Advanced installation type.
After installing the Oracle Database software, Oracle Universal Installer runs
postinstallation configuration tools, such as Net Configuration Assistant
(NETCA), DBCA, and so on.
4.
On the DBCA Template Selection page, use the template that you copied to a
temporary location in the previous section. Use the browse option to select the
template location.
Select the option that you want to deploy. Your choices are the following: Oracle
RAC database; Oracle RAC One Node database; or Oracle single-instance
database.
5.
After creating the Oracle RAC database, DBCA displays the Password
Management page on which you must change the passwords for database users
who have SYSDBA and SYSOPER privileges. When DBCA exits, the conversion
process is complete.
Converting Single Instance on a Cluster to Oracle RAC One Node Using DBCA
Use DBCA to convert a single-instance Oracle Database to Oracle RAC One Node by
using the following procedure:
1.
Change directory to $ORACLE_HOME/bin.
15-4 Oracle Real Application Clusters Administration and Deployment Guide
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
2.
Start DBCA:
$ dbca
3.
From the Welcome window, select Oracle RAC One Node database.
4.
Use the template that you selected to deploy in the previous section.
Converting Single Instance on a Cluster to Oracle RAC Using DBCA
There are three scenarios in which a single-instance database can exist on a cluster
node:
•
Scenario 1: The Oracle home for the single-instance database was installed on a
cluster node and has Oracle RAC enabled.
•
Scenario 2: The Oracle home for the single-instance database was installed on a
cluster node, but the Oracle RAC feature is disabled for this Oracle home.
•
Scenario 3: The Oracle home for the single-instance database was installed on only
the local node in a cluster. This happens when you select the Local Installation
option on the Oracle Universal Installer Specify Hardware Cluster Installation
page during the Oracle Database 12c installation.
Related Topics:
Single-Instance Database on a Cluster Running from an Oracle RAC-Enabled
Home
Single-Instance Database on a Cluster Running from an Oracle RAC-Disabled
Home
Converting Oracle Database Installations to Oracle RAC Using DBCA
Install Oracle Database 12c Software with Oracle RAC
Single-Instance Database on a Cluster Running from an Oracle RAC-Enabled Home
Perform the following procedures to convert a single-instance database on a cluster
node running from an Oracle home that has the Oracle RAC option enabled.
1.
Use DBCA to create a preconfigured image of your single-instance database. To
perform the conversion manually, shut down the single-instance database.
2.
Add nodes to your cluster. Ensure that all nodes can access the shared storage
used by Oracle Clusterware and Oracle RAC.
3.
From the existing Oracle home, extend this home to the new nodes.
4.
From a newly added node, configure the listeners on the additional nodes using
NETCA. Choose the same port number and protocol that you used on the existing
node. If NETCA displays the existing node in the node list page, then do not select
this node, because the listener is already configured on it.
5.
Convert the database using one of the following procedures:
•
Automated Conversion Procedure Using DBCA
•
Manual Conversion Procedure
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-5
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
Related Topics:
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance
database by using the following procedure:
Oracle Clusterware Administration and Deployment Guide
Adding Oracle RAC to Nodes with Oracle Clusterware Installed
Automated Conversion Procedure Using DBCA
If you used DBCA to create a preconfigured image of your single-instance database as
described in a previous section, then perform the following steps to complete the
conversion to an Oracle RAC database:
1.
Start DBCA from the initial node. Select the names of the nodes to include as part
of your cluster database. On the Template Selection page, select the preconfigured
template that you created. Enter the database name and respond to the remaining
DBCA prompts.
2.
Specify the shared storage location for the Oracle Database data files. To use raw
devices for the data files, you cannot use DBCA.
After creating the Oracle RAC database, DBCA displays the Password Management
page on which you must change the passwords for the database users who have
SYSDBA and SYSOPER privileges. When DBCA exits, the conversion process is
complete.
Related Topics:
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance
database by using the following procedure:
Manual Conversion Procedure
Manual Conversion Procedure
If you did not use DBCA to create a preconfigured image of your single-instance
database as described in a previous section, then perform the following steps to
complete the conversion:
1.
Create the Optimal Flexible Architecture directory structure on each of the nodes
that you have added.
2.
Re-create the control files by running the CREATE CONTROLFILE SQL statement
with the REUSE keyword and specify MAXINSTANCES and MAXLOGFILES, and so
on, as needed for your Oracle RAC configuration. The MAXINSTANCES
recommended default is 32.
3.
Shut down the database instance.
4.
If your single-instance database was using an SPFILE, then create a temporary
parameter file (PFILE) from the SPFILE using the following SQL statement:
CREATE PFILE='pfile_name' from spfile='spfile_name'
15-6 Oracle Real Application Clusters Administration and Deployment Guide
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
5.
Set the CLUSTER_DATABASE parameter to TRUE, and set the INSTANCE_NUMBER
parameter to a unique value for each instance, using the sid.parameter=value
syntax.
If you optimized memory usage on your single-instance database, then adjust the
size of the system global area (SGA) to avoid swapping and paging when you
convert to Oracle RAC. You should make this adjustment because Oracle RAC
requires about 350 bytes for each buffer to accommodate the Global Cache Service
(GCS). For example, if you have 10,000 buffers, then Oracle RAC requires
approximately 350 multiplied by 10,000 bytes more memory. Therefore, adjust the
size of the SGA by changing the DB_CACHE_SIZE and DB_nK_CACHE_SIZE
parameters accordingly.
6.
Start the database instance using the PFILE created in Step 4.
7.
If your single-instance database was using automatic undo management, then
create an undo tablespace for each additional instance using the CREATE UNDO
TABLESPACE SQL statement.
8.
Create redo threads that have at least two redo logs for each additional instance.
Enable the new redo threads by using an ALTER DATABASE SQL statement. Then,
shut down the database instance.
9.
Copy the Oracle password file from the initial node, or from the node on which
you are working, to the corresponding location on the additional nodes on which
the cluster database will have an instance. Replace the ORACLE_SID name in each
password file appropriately for each additional instance.
10. Set the REMOTE_LISTENER parameter to the single client access name (SCAN)
and port.
11. Configure the net service entries for the database and instances, and address
entries for the LOCAL_LISTENER for each instance and for the
REMOTE_LISTENER in the tnsnames.ora file, and copy the tnsnames.ora file
to all nodes.
12. Create the SPFILE from the PFILE.
13. Create the $ORACLE_HOME/dbs/initsid.ora file that contains the following
entry, where spfile_path_name is the complete path name of the SPFILE:
spfile='spfile_path_name'
14. On the local node, use SQL*Plus to run catclust.sql. This script creates the
dictionary views needed for Oracle RAC databases. For example:
SQL> start ?/rdbms/admin/catclust.sql
15. Add the configuration for the Oracle RAC or Oracle RAC One Node database and
its instance-to-node mapping using SRVCTL.
a.
To add the configuration of an Oracle RAC database, use the following
commands:
$ srvctl add database -dbname db_name -oraclehome Oracle_home -spfile
spfile_path_name
$ srvctl add instance -dbname db_name -instance inst1_name -node node1_name
$ srvctl add instance -dbname db_name -instance inst2_name -node node2_name
...
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-7
Converting to Oracle RAC and Oracle RAC One Node Using DBCA
b.
To add the configuration of an Oracle RAC One Node database, use the
following command:
$ srvctl add database -dbname db_name -dbtype RACONENODE -oraclehome
Oracle_home
-spfile spfile_path_name
16. Start the Oracle RAC or Oracle RAC One Node database using SRVCTL:
srvctl start database -d db_name
After starting the database with SRVCTL, your conversion process is complete. You
can run the following SQL statement to see the status of all the instances in your
Oracle RAC database:
SQL> SELECT * FROM v$active_instances;
Related Topics:
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance
database by using the following procedure:
Oracle Real Application Clusters Installation Guide
Single-Instance Database on a Cluster Running from an Oracle RAC-Disabled Home
You can create a single-instance database on a cluster running from an Oracle home
with the Oracle RAC option disabled. To create an Oracle home on a cluster with
Oracle RAC disabled, you can select local and non-cluster on the Node Selection Page
of Oracle Universal Installer when installing the Oracle Database software. You can
also performed a one-node cluster (with Oracle RAC) installation, but later disable the
Oracle RAC option.
Perform the following procedures to convert this type of single-instance database to an
Oracle RAC or Oracle RAC One Node database:
1.
Use DBCA to create a preconfigured image of your single-instance database as
described in a previous section. To perform the conversion manually, shut down
the single-instance database.
2.
Change the directory to the lib subdirectory in the rdbms directory under the
Oracle home.
3.
Relink the oracle binary by running the following commands:
make -f ins_rdbms.mk rac_on
make -f ins_rdbms.mk ioracle
4.
Add nodes to your cluster. Ensure that all nodes can access the shared storage
used by Oracle Clusterware and Oracle RAC.
Related Topics:
Use DBCA to Create an Image of the Single-Instance Database
Use DBCA to create a preconfigured image of your single-instance
database by using the following procedure:
Oracle Clusterware Administration and Deployment Guide
15-8 Oracle Real Application Clusters Administration and Deployment Guide
Preparing to Convert with rconfig and Oracle Enterprise Manager
Preparing to Convert with rconfig and Oracle Enterprise Manager
You can use rconfig, or Oracle Enterprise Manager to assist with converting a
single-instance database installation to an Oracle RAC database. The first of these,
rconfig, is a command-line utility. Oracle Enterprise Manager Cloud Control
database administration option, Convert to Cluster Database, provides a GUI-based
conversion tool. The following sections describe how to use these conversion tools:
•
Prerequisites for Converting to Oracle RAC Databases
•
Configuration Changes During Oracle RAC Conversion Using rconfig
•
Converting Databases to Oracle RAC Using rconfig or Oracle Enterprise Manager
•
Converting Databases to Oracle RAC Using Oracle Enterprise Manager
Note:
Before you start the conversion, back up your existing database; you should
take a backup of your database before starting any major change.
Prerequisites for Converting to Oracle RAC Databases
Before you convert a single-instance database to an Oracle RAC database, ensure that
the following conditions are met for each cluster node that you intend to make an
Oracle RAC database node:
•
Oracle Clusterware 12c is installed, configured, and running.
•
Oracle RAC 12c software is installed.
•
The Oracle software has the Oracle RAC option enabled.
•
Shared storage, either Oracle Cluster File System or Oracle ASM, is available and
accessible from all nodes.
•
User equivalence exists for the oracle account, or the user account used to install
the Oracle software.
•
If you intend to use Oracle Enterprise Manager, then the Oracle Management
Agent on each node is configured and running, and is configured with cluster and
host information.
•
You have backed up your existing database.
Note:
You must use clustered Oracle ASM instances for Oracle RAC databases.
Configuration Changes During Oracle RAC Conversion Using rconfig
The following changes occur when you convert a single-instance database to Oracle
RAC using the rconfig utility:
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-9
Preparing to Convert with rconfig and Oracle Enterprise Manager
•
During the conversion, rconfig places the target Oracle RAC database into
archive log mode, and enables archiving for the database. If you do not plan to
use archive log space, then you can disable archive logging after the conversion
has completed.
•
For the Shared Storage Type value, if you enter CFS, and you use a cluster file
system for your single-instance database storage, then rconfig converts the
environment to use Oracle Managed Files for database storage, and places the
data files in a subdirectory located under the shared storage location.
•
During the conversion, rconfig moves database files to a specified shared
location, and configures them using Oracle Managed Files.
To avoid using Oracle Managed Files with your converted database, the singleinstance database files must be located in a shared file system, and you must
indicate that rconfig should not move the files.
Converting Databases to Oracle RAC Using rconfig or Oracle Enterprise Manager
The following list describes scenarios for converting a single-instance Oracle database
to an Oracle RAC database:
•
Converting a single-instance Oracle Database 12c database to an Oracle RAC 12c
database, running out of the same Oracle home and using the same data files as
the single-instance database.
In this scenario, run the rconfig utility from the Oracle RAC database home, or
use the Convert to RAC option on the single-instance database target of Oracle
Enterprise Manager Cloud Control.
•
Converting a single-instance database that uses a release of Oracle Database
earlier than Oracle Database 12c to an Oracle RAC 12c database, running out of
the same Oracle home and using the same data files as the single-instance
database
In this scenario, use Oracle Universal Installer and Database Upgrade Assistant
(DBUA) to update the single-instance database to Oracle Database 12c. Then use
rconfig or the Oracle Enterprise Manager Convert to RAC option, as described
in the preceding scenario.
•
Converting a single-instance Oracle Database 12c to an Oracle RAC 12c database,
running out of a different Oracle home and using the same data files as the singleinstance database.
In this scenario, run the rconfig utility in the target database home, or use the
Convert to RAC option in the single-instance database target of Oracle Enterprise
Manager Cloud Control. Provide the file storage location when prompted.
Note:
If you specify Oracle home users for both the target database home and the
source database home, then the Oracle home user for the target database home
must be the same as the Oracle home user for the source database home.
•
Converting a single-instance Oracle Database 12c to an Oracle RAC 12c database,
running out of a different Oracle home, and where the host on which the singleinstance database runs is not a node used by the Oracle RAC database.
15-10 Oracle Real Application Clusters Administration and Deployment Guide
Preparing to Convert with rconfig and Oracle Enterprise Manager
In this scenario, create a clone image of the single-instance database, and move the
clone image to a host that is one of the nodes used by the Oracle RAC database.
Then use rconfig or the Oracle Enterprise Manager Convert to RAC option, as
described in the preceding scenario.
Converting Databases to Oracle RAC Using Oracle Enterprise Manager
You can use Oracle Enterprise Manager Cloud Control to convert a single-instance
database to an Oracle RAC database.
To use this feature, complete the following steps:
1.
Log in to Oracle Enterprise Manager Cloud Control. From the Home page, click
the Targets tab.
2.
On the Targets page, click the Databases secondary tab, and click the link in the
Names column of the database to convert to Oracle RAC.
3.
On the Database home page, from the Availability menu, select Convert to
Cluster Database.
4.
Log in as the database user SYS with SYSDBA privileges to the database you want
to convert, and click Next.
5.
On the Convert to Cluster Database: Cluster Credentials page, provide a user
name and password for the oracle user and password of the target database to
convert. If the target database is using Oracle ASM, then also provide the
SYSASM user and password, and then click Next.
6.
On the Hosts page, select the host nodes in the cluster to be cluster members in
the installed Oracle RAC database. When you have completed your selection,
click Next.
7.
On the Convert to Database: Options page, select whether you want to use the
existing listener and port number, or specify a new listener and port number for
the cluster. Also provide a prefix for cluster database instances on the cluster.
When you have finished entering information, click Next, or click Help if you
need assistance in deciding how to enter information.
8.
On the Convert to Cluster Database: Shared Storage page, either select the option
to use your existing shared storage area, or select the option to have your database
files copied to a new shared storage location. Also, decide if you want to use your
existing fast recovery area or copy your recovery files to a new fast recovery area
using files managed by Oracle Database.
If you use Oracle ASM, then Oracle recommends that you place the data files and
the recovery files in separate failure groups. A failure group is defined by shared
hardware, such as a controller shared between two disks, or two disks that are on
the same spindle. If two disks share hardware that could fail, making both disks
unavailable, then theses disks are said to be in the same failure group. If you do
not use Oracle ASM, then Oracle recommends that the data files and the recovery
files are stored in separate locations, for example, separate Oracle ASM failure
groups, so that a hardware failure does not affect availability.
When you have finished entering information, click Next, or click Help if you
need assistance in deciding how to enter information.
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-11
Converting Databases to Oracle RAC Using rconfig
9.
On the Convert to Cluster Database: Review page, review the options you have
selected. Click Submit Job to proceed with the conversion. To change any options
you have selected, click Back. To cancel the conversion, click Cancel.
10. On the Confirmation page, click View Job to check the status of the conversion.
Related Topics:
Oracle Database Upgrade Guide
Converting Databases to Oracle RAC Using rconfig
You can use the command-line utility rconfig to convert a single-instance database
to an Oracle RAC database, or to convert it to an Oracle RAC One Node database,
depending on the values you provide in the ConvertToRAC.xml file. To use this
feature, complete the following steps:
1.
As the oracle user, navigate to the directory $ORACLE_HOME/assistants/
rconfig/sampleXMLs, and open the file ConvertToRAC.xml using a text
editor, such as vi.
2.
Review the ConvertToRAC.xml file, and modify the parameters as required for
your system. The XML sample file contains comments that provide instructions
for how to configure the file.
Caution:
Set the convert option Convert verify="ONLY" to perform a test
conversion to ensure that a conversion can be completed successfully.
When you have finished modifying parameters, save the file with a name of the
format file_name.xml. Make a note of the name you select.
3.
Navigate to the directory $ORACLE_HOME/bin, and use the following command
to run the command rconfig, where input.xml is the name of the XML input
file you configured in Step 2:
rconfig input.xml
For example, if you create an input XML file called convert.xml, then you
would use the following command
$ ./rconfig convert.xml
15-12 Oracle Real Application Clusters Administration and Deployment Guide
Example of rconfig XML Input Files for ConvertToRAC
Note:
The Convert verify option in the ConvertToRAC.xml file has three
options:
•
Convert verify="YES": rconfig performs checks to ensure that the
prerequisites for single-instance to Oracle RAC conversion have been met
before it starts conversion
•
Convert verify="NO": rconfig does not perform prerequisite checks,
and starts conversion
•
Convert verify="ONLY" rconfig only performs prerequisite checks; it
does not start conversion after completing prerequisite checks
If performing the conversion fails, then use the following procedure to recover and
reattempt the conversion.:
1.
Attempt to delete the database using the DBCA delete database option.
2.
Restore the source database.
3.
Review the conversion log, and fix any problems reported by rconfig that may
have caused the conversion failure. The rconfig log files are under the rconfig
directory in $ORACLE_BASE/cfgtoollogs.
4.
Reattempt the conversion.
Related Topics:
Oracle Database Upgrade Guide
Example of rconfig XML Input Files for ConvertToRAC
The following are two examples of an XML ConvertToRAC input file for the
rconfig utility. Example 15-1 is an XML input file to convert a single-instance
database with Oracle ASM to a policy-managed Oracle RAC database (using server
pools) on Oracle ASM storage. Example 15-2 is an XML input file to convert a singleinstance database with Oracle ASM to an administrator-managed Oracle RAC
database.
Example 15-1
Databases
Example rconfig ConvertToRAC XML File for Policy-Managed
<?xml version="1.0" encoding="UTF-8"?>
<n:RConfig xmlns:n="http://www.example.com/rconfig"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.example.com/rconfig">
<n:ConvertToRAC>
<!-- Verify does a precheck to ensure all pre-requisites are met, before the
conversion is attempted. Allowable values are: YES|NO|ONLY -->
<n:Convert verify="YES">
<!--Specify current OracleHome of non-rac database for SourceDBHome -->
<n:SourceDBHome>/oracle/product/12.1.0/db_1</n:SourceDBHome>
<!--Specify OracleHome where the rac database should be configured. It can be same
as SourceDBHome -->
<n:TargetDBHome>/oracle/product/12.1.0/db_1</n:TargetDBHome>
<!--Specify SID of non-rac database and credential. User with sysdba role is
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-13
Example of rconfig XML Input Files for ConvertToRAC
required to perform conversion -->
<n:SourceDBInfo SID="sales">
<n:Credentials>
<n:User>sys</n:User>
<n:Password>oracle</n:Password>
<n:Role>sysdba</n:Role>
</n:Credentials>
</n:SourceDBInfo>
<!--Specify the list of existing or new server pools which are used by the
Policy Managed Cluster Database. -->
<n:ServerPoolList>
<n:ExistingServerPool name="custom"/>
<n:NewServerPool name="newpool" cardinality="2"/>
</n:ServerPoolList>
<!--Specify RacOneNode along with servicename to convert database to RACOne
Node -->
<!--n:RacOneNode servicename="salesrac1service"/-->
<!--InstancePrefix is not required for Policy Managed database. If specified, it
will be ignored. Instance names are generated automatically based on db_unique_
name for Policy Managed dababase.-->
<!-- Listener details are no longer needed starting 11.2. Database is registered
with default listener and SCAN listener running from Oracle Grid Infrastructure
home. -->
<!--Specify the type of storage to be used by rac database. Allowable values are
CFS|ASM. The non-rac database should have same storage type. ASM credentials are
no needed for conversion. -->
<n:SharedStorage type="ASM">
<!--Specify Database Area Location to be configured for rac database.If this field
is left empty, current storage will be used for rac database. For CFS, this field
will have directory path. -->
<n:TargetDatabaseArea>+ASMDG</n:TargetDatabaseArea>
<!--Specify Fast Recovery Area to be configured for rac database. If this field is
left empty, current recovery area of non-rac database will be configured for rac
database. If current database is not using recovery Area, the resulting rac
database will not have a recovery area. -->
<n:TargetFlashRecoveryArea>+ASMDG</n:TargetFlashRecoveryArea>
</n:SharedStorage>
</n:Convert>
</n:ConvertToRAC>
</n:RConfig>
Example 15-2
Databases
Example rconfig ConvertToRAC XML File for Administrator-Managed
<?xml version="1.0" encoding="UTF-8"?>
<n:RConfig xmlns:n="http://www.example.com/rconfig"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.example.com/rconfig rconfig.xsd">
<n:ConvertToRAC>
<!-- Verify does a precheck to ensure all pre-requisites are met, before the
conversion is attempted. Allowable values are: YES|NO|ONLY -->
<n:Convert verify="YES">
<!--Specify current OracleHome of non-rac database for SourceDBHome -->
<n:SourceDBHome>/oracle/product/12.1.0/db_1</n:SourceDBHome>
<!--Specify OracleHome where the rac database should be configured. It can be same
as SourceDBHome -->
<n:TargetDBHome>/oracle/product/12.1.0/db_1</n:TargetDBHome>
<!--Specify SID of non-rac database and credential. User with sysdba role is
required to perform conversion -->
<n:SourceDBInfo SID="sales">
<n:Credentials>
15-14 Oracle Real Application Clusters Administration and Deployment Guide
Postconversion Steps
<n:User>sys</n:User>
<n:Password>oracle</n:Password>
<n:Role>sysdba</n:Role>
</n:Credentials>
</n:SourceDBInfo>
<!--Specify the list of nodes that should have rac instances running for the Admin
Managed Cluster Database. LocalNode should be the first node in this nodelist.
-->
<n:NodeList>
<n:Node name="node1"/>
<n:Node name="node2"/>
</n:NodeList>
<!--Specify RacOneNode along with servicename to convert database to RACOne
Node -->
<!--n:RacOneNode servicename="salesrac1service"/-->
<!--Instance Prefix tag is optional starting with 11.2. If left empty, it is
derived from db_unique_name.-->
<n:InstancePrefix>sales</n:InstancePrefix>
<!-- Listener details are no longer needed starting 11.2. Database is registered
with default listener and SCAN listener running from Oracle Grid Infrastructure
home. -->
<!--Specify the type of storage to be used by rac database. Allowable values are
CFS|ASM. The non-rac database should have same storage type. ASM credentials
are not needed for conversion. -->
<n:SharedStorage type="ASM">
<!--Specify Database Area Location to be configured for rac database.If this field
is left empty, current storage will be used for rac database. For CFS, this
field will have directory path. -->
<n:TargetDatabaseArea>+ASMDG</n:TargetDatabaseArea>
<!--Specify Fast Recovery Area to be configured for rac database. If this field is
left empty, current recovery area of non-rac database will be configured for rac
database. If current database is not using recovery Area, the resulting rac
database will not have a recovery area. -->
<n:TargetFlashRecoveryArea>+ASMDG</n:TargetFlashRecoveryArea>
</n:SharedStorage>
</n:Convert>
</n:ConvertToRAC>
</n:RConfig>
Postconversion Steps
After completing the conversion, note the following recommendations for Oracle RAC
environments, as described in the following:
•
Follow the recommendations for using load balancing and transparent application
failover, as previously described
•
Use locally managed tablespaces instead of dictionary managed tablespaces to
reduce contention and manage sequences in Oracle RAC as described in Oracle
Database Administrator’s Guide
•
Follow the guidelines for using automatic segment space management as
described in Oracle Database Administrator’s Guide
The buffer cache and shared pool capacity requirements in Oracle RAC are slightly
greater than the requirements for single-instance Oracle databases. Therefore, you
should increase the size of the buffer cache by about 10%, and the size of the shared
pool by about 15%.
Converting Single-Instance Oracle Databases to Oracle RAC and Oracle RAC One Node 15-15
Postconversion Steps
Related Topics:
Workload Management with Dynamic Database Services
Workload management includes load balancing, enabling clients for
Oracle Real Application Clusters (Oracle RAC), distributed transaction
processing, and services.
Oracle Database Administrator’s Guide
Oracle Database Administrator’s Guide
15-16 Oracle Real Application Clusters Administration and Deployment Guide
A
Server Control Utility Reference
Use the Server Control Utility (SRVCTL) to manage Oracle Real Application Clusters
(Oracle RAC) configuration information.
This appendix includes the following topics:
•
SRVCTL Usage Information
•
Specifying Command Parameters as Keywords Instead of Single Letters
•
Character Set and Case Sensitivity of SRVCTL Object Values
•
Summary of Tasks for Which SRVCTL Is Used
•
Using SRVCTL Help
•
SRVCTL Privileges and Security
•
Additional SRVCTL Topics
•
Deprecated SRVCTL Subprograms or Commands
•
SRVCTL Command Reference
SRVCTL Usage Information
SRVCTL is installed on each node in a cluster by default. To use SRVCTL, log in to the
operating system of a node and enter the SRVCTL command and its parameters in
case-sensitive syntax.
•
Only use the version of SRVCTL that is provided with Oracle Database 12c on
Oracle RAC databases that are created for or upgraded to Oracle Database 12c.
The version of SRVCTL must be the same as the version of the object (listeners,
Oracle ASM instances, Oracle RAC databases and their instances, and services)
being managed. To ensure the versions are the same release, run SRVCTL
commands from the Oracle home of the database or object you are managing.
•
SRVCTL does not support concurrent executions of commands on the same
object. Therefore, run only one SRVCTL command at a time for each database,
service, or other object.
•
When specifying a comma-delimited list as part of a SRVCTL command, there
should not be any spaces between the items in the list. For example:
srvctl add database -serverpool "serverpool1,serverpool3"
When you specify a comma-delimited list in a Windows environment, you must
enclose the list in double quotation marks (""). You can enclose a commadelimited list in double quotation marks in a Linux or UNIX environment but
they will be ignored.
Server Control Utility Reference A-1
Specifying Command Parameters as Keywords Instead of Single Letters
•
If you are entering a SRVCTL command, and you want to continue the input on a
new line, then you can use the operating system continuation character. In Linux,
this is the backslash (\) symbol.
•
A SRVCTL command that produces no output is a successful command. Not all
SRVCTL commands return a message when it completes, successfully. However,
if a SRVCTL command fails, then it always returns an error message.
•
You can use the -eval parameter with several SRVCTL commands. This
parameter, when you use it, enables you to simulate running a command without
making any changes to the system. SRVCTL returns output that informs you what
will happen if you run a particular command. For example, to know what might
happen if you relocate a server:
$ srvctl relocate server –servers "rac1" –eval –serverpool pool2
Database db1
will stop on node rac1
will start on node rac7
Service mySrv1
will stop on node rac1, it will not run on any node
Service myServ2
will stop on node rac1
will start on node rac6
Server rac1
will be moved from pool myPoolX to pool pool2
The -eval parameter is available with the following commands:
–
srvctl add database
–
srvctl add service
–
srvctl add srvpool
–
srvctl modify database
–
srvctl modify service
–
srvctl modify srvpool
–
srvctl relocate server
–
srvctl relocate service
–
srvctl remove srvpool
–
srvctl start database
–
srvctl start service
–
srvctl stop database
–
srvctl stop service
Specifying Command Parameters as Keywords Instead of Single Letters
Before Oracle Database 12c, the SRVCTL command-line interface used single letter
parameters. However, this imposes a limit on the number of unique parameters
available for use with SRVCTL commands. SRVCTL command parameters introduced
A-2 Oracle Real Application Clusters Administration and Deployment Guide
Character Set and Case Sensitivity of SRVCTL Object Values
in Oracle Database 12c are full words instead of single letters, such as multicastport and -subdomain.
To support backward compatibility, you can use a mix of single-letter parameters and
new keyword parameters. New parameters introduced with keywords can be used
with single letter parameters.
Note:
Starting with Oracle Database 12c, the single letter parameters are deprecated
in favor of the keyword parameters to avoid using the same letter to
implement different functionality depending on the command.
You can obtain the single-letter equivalents, where applicable, by adding the compatible parameter after the -help parameter.
Character Set and Case Sensitivity of SRVCTL Object Values
SRVCTL interacts with many different types of objects. The character set and name
length limitations, and whether the object name is case sensitive, can vary between
object types.
Table A-1
String Restrictions for SRVCTL Object Names
Object Type
Character Set Limitations
db_domain
Alpha-numeric characters,
underscore (_), and number sign
(#)
db_unique_nam
e
diskgroup_nam
e
Case
Sensitive?
Maximum Length
128 characters
Alpha-numeric characters,
underscore (_), number sign (#),
and dollar sign ($); the first 8
characters must be unique
because those characters are
used to form instance names for
policy-managed databases
No
30 characters but the
first 8 characters must
be unique relative to
any other database in
the same cluster
Naming disk groups have the
same limitations as naming
other database objects.
No (all names
are converted
to uppercase)
See Also: Oracle Database SQL
Language Reference for more
information about database
object naming rules
instance_name
Alpha-numeric characters
Depends on
the platform
15 characters
listener_name
node_name
No
Server Control Utility Reference A-3
Summary of Tasks for Which SRVCTL Is Used
Table A-1
(Cont.) String Restrictions for SRVCTL Object Names
Object Type
Character Set Limitations
Case
Sensitive?
scan_name
The first character must be an
alphabetic character
No
server_pool
Alpha-numeric characters,
underscore (_), number sign (#),
period (.), and dollar sign ($);
the name cannot begin with a
period, contain single quotation
marks (''), nor can the name be
"Generic" or "Free" because
those two names are reserved
for the built-in server pools
250 characters
250 characters
service_name
volume_name
Maximum Length
Alphanumeric characters;
dashes (-) are not allowed and
the first character must be an
alphabetic character.
No
11 characters
Summary of Tasks for Which SRVCTL Is Used
Use SRVCTL to manage databases, instances, cluster databases, cluster database
instances, Oracle ASM instances and disk groups, services, listeners, or other
clusterware resources.
•
Cluster Database Configuration Tasks
Tasks
Commands
Add, modify, and
delete cluster database
configuration
information
srvctl add database
Add an instance to or
delete an instance from
the configuration of a
cluster database
srvctl add instance
Add a service to or
delete a service from
the configuration of a
cluster database
srvctl add service
Move instances and
services in a cluster
database configuration
and modify service
configurations
srvctl relocate database
srvctl modify database
srvctl remove database
srvctl remove instance
srvctl remove service
srvctl relocate service
srvctl modify instance
srvctl modify service
A-4 Oracle Real Application Clusters Administration and Deployment Guide
Summary of Tasks for Which SRVCTL Is Used
•
•
Tasks
Commands
Set and unset the
environment for an
instance or service in a
cluster database
configuration
srvctl modify instance
Set and unset the
environment for an
entire cluster database
in a cluster database
configuration
srvctl setenv database
srvctl modify service
srvctl unsetenv database
General Cluster Database Administration Tasks
Tasks
Commands
Start and stop cluster
databases
srvctl start database
Start and stop cluster
database instances
srvctl start instance
Start, stop, and relocate
cluster database
services
srvctl start service
Obtain statuses of
cluster databases,
cluster database
instances, or cluster
database services
srvctl status database
srvctl stop database
srvctl stop instance
srvctl stop service
srvctl relocate service
srvctl status instance
srvctl status service
Node-Level Tasks
Tasks
Commands
Administering VIPs
srvctl add vip
srvctl config vip
srvctl disable vip
srvctl enable vip
srvctl getenv vip
srvctl modify vip
srvctl relocate vip
srvctl remove vip
srvctl setenv vip
srvctl start vip
srvctl status vip
srvctl stop vip
srvctl unsetenv vip
Server Control Utility Reference A-5
Using SRVCTL Help
Tasks
Commands
Administering node
applications
srvctl add nodeapps
srvctl disable nodeapps
srvctl enable nodeapps
srvctl getenv nodeapps
srvctl modify nodeapps
srvctl remove nodeapps
srvctl setenv nodeapps
srvctl unsetenv nodeapps
Related Topics:
Oracle Clusterware Administration and Deployment Guide
Using SRVCTL Help
This section includes information about using context sensitive help with SRVCTL.
To see help for all SRVCTL commands, from the command line enter:
srvctl -help
To see the command syntax and a list of parameters for each SRVCTL command, from
the command line enter:
srvctl command (or verb) object (or noun) -help
When you request online help for a command using -help, SRVCTL prints the full
words for each parameter. You can obtain the single-letter equivalents, where
applicable, by adding the -compatible parameter after the -help parameter. For
example:
$ srvctl config database -help -compatible
The preceding command prints usage information for the srvctl config
database command, listing all parameters as full words followed by their singleletter equivalents in parentheses, where applicable.
To see the SRVCTL version number enter:
$ srvctl -version
SRVCTL Privileges and Security
To use SRVCTL to change your Oracle RAC database configuration, log in to the
operating system as the software owner of the home that you want to manage.
For example, if different users installed Oracle Database and the Oracle Grid
Infrastructure, then log in as the database software owner (for example, ora_db) to
manage databases and log in as the Oracle Grid Infrastructure software owner (for
example, ora_asm) to manage the Oracle ASM instances.
Users who are members of the OSDBA operating system group can start and stop the
database. To stop and start an Oracle ASM instance, you must be a member of the
OSASM operating system group.
To create or register objects such as listeners, Oracle Notification Services, and
services, you must be logged in to the operating system as the software owner of the
A-6 Oracle Real Application Clusters Administration and Deployment Guide
Additional SRVCTL Topics
Oracle home. The objects you create or register for that Oracle home will run under
the user account of the owner of the Oracle home. Databases run as the database
installation owner of the home from which they run.
To perform srvctl add operations on any object, you must be logged in as the
Oracle account owner of the home on which the object runs.
For some SRVCTL commands, on Linux and UNIX systems, you must be logged in as
root, and on Windows systems, you must be logged in as a user with Administrator
privileges to run them. In this appendix, those commands are preceded by the root
prompt (#) in the command examples.
Additional SRVCTL Topics
•
Use SRVCTL to manage Oracle-supplied resources such as listener, instances, disk
groups, and networks, and CRSCTL for managing Oracle Clusterware and its
resources.
Note:
Oracle strongly discourages directly manipulating Oracle-supplied resources
(resources whose names begin with ora) using CRSCTL. This could adversely
impact the cluster configuration.
•
Although you may be able to cancel running SRVCTL commands by pressing the
Control-C keys, you may corrupt your configuration data by doing this.
You are strongly advised not to attempt to terminate SRVCTL in this manner.
Deprecated SRVCTL Subprograms or Commands
A number of SRVCTL commands and parameters have been deprecated in this
release.
Single Character Parameters for all SRVCTL Commands
Single-character parameters have been deprecated in Oracle Database 12c.
Use the full keyword for each parameter instead. To support older tools and scripts
that still use single-character parameters, the current version of SRVCTL supports
both single-character parameters and full keyword parameters.
The command reference in this appendix shows the keywords for each SRVCTL
command. Table A-2 lists the deprecated single-character parameters.
Table A-2
Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
A
address
{VIP_name |
IP}/netmask/
[if1[|if2...]]
VIP address
specification for node
applications
Node applications,
VIP, network, Listener,
SCAN VIP, and SCAN
listener commands
Server Control Utility Reference A-7
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
a
all
Values
Description
Related Commands
All resources of that
kind
srvctl config
database
Common
Comma-delimited
list of Oracle ASM
disk groups
Database, instance,
Oracle ASM, disk
group, and file system
commands
Print detailed
configuration
information
Common
A comma-delimited
list of available
instances
Service and server
pool commands
abort
Abort failed online
relocation
Relocate database
a
viponly
Display VIP
configuration
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
B
rlbgoal
{NONE|
SERVICE_TIME|
THROUGHPUT}
The runtime load
balancing goal of a
service
Service and server
pool commands
c
currentno
de
current_node
Node name from
which to relocate the
service
Service and server
pool commands
c
cardinali
ty
{UNIFORM|
SINGLETON}
Whether the service
should run on every
active server in the
server pool
(UNIFORM) or just
one server
(SINGLETON)
Service and server
pool commands
c
dbtype
type
Type of database:
Oracle RAC One
Node, Oracle RAC,
or single instance
Database, instance,
Oracle ASM, disk
group, and file system
commands
d
db or
database
db_unique_name
Database unique
name
Common
d
device
volume_device
Volume device path
Database, instance,
Oracle ASM, disk
group, and file system
commands
a
diskgroup
a
detail
a
available
a
diskgroup_list
available_list
A-8 Oracle Real Application Clusters Administration and Deployment Guide
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
d
domain
e
emport
e
Values
Description
Related Commands
Display subdomain
served by GNS
OC4J, home, CVU, and
GNS commands
em_port_number
Local listen port for
Oracle Enterprise
Manager
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
failovert
ype
{NONE|SESSION
BASIC|
TRANSACTION}
The failover type for
a service
Service and server
pool commands
e
server
server_list
Candidate server list
for Oracle RAC One
Node database
Database, instance,
Oracle ASM, disk
group, and file system
commands
f
force
Force remove
Common
g
diskgroup
Disk group name
File system, Diskgroup
commands
g
gsdonly
Display GSD
configuration
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
g
serverpoo
l
A server pool name
Service and server
pool commands
diskgroup_name
server_pool_na
me
server_pool_li
st
Comma-delimited
list of database server
pool names
Database, instance,
Oracle ASM, disk
group, and file system
commands
Common
h
help
i
importanc
e
number
A number that
represents the
importance of the
server pool
Service and server
pool commands
i
instance
instance_name
instance_list
Instance name prefix
for administratormanaged Oracle
RAC One Node
database
Database, instance,
Oracle ASM, disk
group, and file system
commands
A comma-delimited
list of instance names
I
ip
ip_address
VIP address on
which GNS is to
listen
OC4J, home, CVU, and
GNS commands
i
oldinst
instance_name
The old instance
name
Service and server
pool commands
Server Control Utility Reference A-9
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
i
scannumbe
r
scan_ordinal
_number
Ordinal number of
the IP address for the
SCAN
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
i
vip
vip_name or
"vip_name_list
"
VIP names
Node applications,
GNS, VIP, network,
listener, SCAN VIP,
and SCAN listener
commands
j
acfspath
acfs_path_list
Comma-delimited
list of Oracle ACFS
paths where the
dependency on the
database will be set
Database, instance,
Oracle ASM, disk
group, and file system
commands
j
clbgoal
{SHORT|LONG}
The connection load
balancing goal for a
service
Service and server
pool commands
k
netnum
network_number
The network number
Service and server
pool commands
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
OC4J, home, CVU, and
GNS commands
List all records in
GNS
OC4J, home, CVU, and
GNS commands
listener_name
The name of a
listener
ASM commands
loglevel
log_level
Specify the level (0-6)
of logging that GNS
should run with
OC4J, home, CVU, and
GNS commands
l
min
number
The minimum size of
the server pool
Service and server
pool commands
l
onslocalp
ort
port_number
Oracle Notification
Service listening port
for local client
connections
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
l
list
l
listener
l
A-10 Oracle Real Application Clusters Administration and Deployment Guide
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
l
role
service_role
Comma-delimited
list of server roles
within double
quotation marks
(""), where each role
is one of PRIMARY,
PHYSICAL_STANDBY
,
LOGICAL_STANDBY,
or
SNAPSHOT_STANDBY
Service and server
pool commands
m
domain
domain_name
The domain for the
database
Database, instance,
Oracle ASM, disk
group, and file system
commands
m
failoverm
ethod
{NONE|BASIC}
The failover method
of a service
Service and server
pool commands
m
multicast
post
The port on which
the GNS daemon is
listening for
multicast requests
OC4J, home, CVU, and
GNS commands
m
path
Mountpoint path
Database, instance,
Oracle ASM, disk
group, and file system
commands
n
name
Advertise a name
through GNS using
the given address
OC4J, home, CVU, and
GNS commands
n
node
node_name
The name of a
specific node
Common
n
nodes
node_list
A comma-delimited
list of node names
File system commands
n
dbname
database_name
The database name
(DB_NAME), if
different from the
unique name
specified by the -db
parameter
Database, instance,
Oracle ASM, disk
group, and file system
commands
n
scanname
scan_name
Fully-qualified
SCAN name
(includes the
domain)
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
n
servers
server_list
A comma-delimited
list of candidate
server names
Service and server
pool commands
mountpoint_pat
h
Server Control Utility Reference A-11
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
n
targetnod
e
node_name
Node name to which
to relocate the service
Service and server
pool commands
o
oraclehom
e
oracle_home
$ORACLE_HOME path
Database commands
p
endpoints
[TCP:]port
_number[/IPC:
key][/NMP:pipe
_name][/TCPS:
s_port][/SDP:
port]
SCAN listener
endpoints
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
p
port
The port which the
GNS daemon uses to
communicate with
the DNS server
OC4J, home, CVU, and
GNS commands
p
rmiport
port_number
OC4J RMI port
number
OC4J, home, CVU, and
GNS commands
P
tafpolicy
{NONE|BASIC}
TAF policy
specification
Service and server
pool commands
p
spfile
spfile_locatio
n
Server parameter file
path
Database, instance,
Oracle ASM, disk
group, and file system
commands
q
notificat
ion
{TRUE|FALSE}
Whether FAN is
enabled for OCI
connections
Service commands
q
query
Query GNS for the
records belonging to
a name
OC4J, home, CVU, and
GNS commands
r
preferred
preferred_list
A comma-delimited
list of preferred
instances
Service and server
pool commands
r
onsremote
port
port_number
Oracle Notification
Service listening port
for connections from
remote hosts
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
r
relocate
Relocate the VIP
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
A-12 Oracle Real Application Clusters Administration and Deployment Guide
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
r
revert
r
role
s
Values
Description
Related Commands
Remove target node
of failed online
relocation request
from the candidate
server list of
administratormanaged Oracle
RAC One Node
database
Relocate database
Role of the standby
database: PRIMARY,
PHYSICAL_STANDBY
,
LOGICAL_STANDBY,
or
SNAPSHOT_STANDBY
Database, instance,
Oracle ASM, disk
group, and file system
commands
onsonly
Display Oracle
Notification Service
daemon
configuration
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
s
skip
Skip checking the
ports
Listener, SCAN, and
SCAN listener.
s
statfile
The file path of the
state_file created
by a previously
executed srvctl
stop home
command
OC4J, home, CVU, and
GNS commands
s
status
Display the status of
GNS
OC4J, home, CVU, and
GNS commands
S
subnet
subnet/net
_mask/[if1[|
if2...]]
Network address
specification for a
network
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
s
service
service_name
service_name_l
ist
The name of a service
Service and server
pool commands
role_type
file_name
A comma-delimited
list of service names
s
startopti
on
start_options
Startup options for
the database (mount,
open, read only)
Database, instance,
Oracle ASM, disk
group, and file system
commands
t
checkinte
rval
time_interval
Interval in minutes
between checks
OC4J, home, CVU, and
GNS commands
t
edition
edition_name
The initial session
edition of a service
Service and server
pool commands
Server Control Utility Reference A-13
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
t
envs
"name_list"
A list of environment
variables
Common
t
namevals
"name=
value,..."
Names and values of
environment
variables
Common
T
nameval
"name=value"
Name and value of a
single environment
variable
Common
t
update
instance_name
The new instance
name
Service and server
pool commands
t
remoteser
vers
host_name[:
port_number]
[,host_name[:
port_number]..
.]
List of remote host
name and port
number pairs for
Oracle Notification
Service daemons
outside this cluster
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
t
stopoptio
n
stop_options
Stop options for the
database (NORMAL,
TRANSACTIONAL,
IMMEDITATE, or
ABORT)
Database, instance,
Oracle ASM, disk
group, and file system
commands
t
toversion
target_version
Version to which you
are downgrading
Database, instance,
Oracle ASM, disk
group, and file system
commands
u
max
number
Maximum size of the
server pool
Service and server
pool commands
u
nettype
network_type
The network server
type, which can be
STATIC, DHCP, or
MIXED
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
u
newinst
Add a new instance
to the service
configuration
Service commands
u
update
Update SCAN
listeners to match the
number of SCAN
VIPs
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
u
user
Oracle user or other
authorized user to
mount and unmount
file systems
Database, instance,
Oracle ASM, disk
group, and file system
commands
v
verbose
Verbose output
Common
oracle_user
A-14 Oracle Real Application Clusters Administration and Deployment Guide
Deprecated SRVCTL Subprograms or Commands
Table A-2
(Cont.) Deprecated Single-Character Parameters for SRVCTL Commands
Single
Letter
Long Form
Values
Description
Related Commands
v
volume
volume_name
Name of a volume
Database, instance,
Oracle ASM, disk
group, and file system
commands
V
versions
w
failoverd
elay
number
Failover delay
Service and server
pool commands
w
nettype
network_type
The network server
type, which can be
STATIC, DHCP, or
MIXED
Node applications,
VIP, network, listener,
SCAN VIP, and SCAN
listener commands
w
timeout
timeout
Online relocation
timeout in minutes
Database, instance,
Oracle ASM, disk
group, and file system
commands
x
dtp
{TRUE | FALSE}
Whether to enable
distributed
transaction
processing
Service and server
pool commands
x
node
node_name
Node name (use this
parameter only with
noncluster databases)
Common
y
noprompt
Suppress the
confirmation prompt
Common
y
policy
{AUTOMATIC |
MANUAL}
Management policy
for the resource
Database, instance,
Oracle ASM, disk
group, file system,
service and server
pool commands
z
failoverr
etry
number
Number of failover
retries
Service and server
pool commands
z
rmdepondi
sk
To remove a
database's
dependency upon
disk groups
Database, instance,
Oracle ASM, disk
group, and file system
commands
Common
Miscellaneous SRVCTL Commands and Parameters
The following command parameters have been deprecated in this release:
Server Control Utility Reference A-15
SRVCTL Command Reference
Table A-3
Deprecated Commands and Parameters for SRVCTL
Command
Deprecated Parameters
srvctl modify asm
-node node_name
srvctl modify
instance
-z
srvctl modify gns
[-ip ip_address] [-advertise host_name -address
address] [-delete host_name -address address] [createalias name -alias alias] [-deletealias
alias]
Instead, use the -node option with the value set to ""
Use the srvctl update gns command instead.
srvctl * oc4j
The oc4j noun has been deprecated and replaced with
qosmserver. SRVCTL still accepts the oc4j noun until it is
desupported.
srvctl add service
The PRECONNECToption with the -tafpolicy parameter is
deprecated.
srvctl modify
service
The -failovermethod {NONE | BASIC} is deprecated.
The PRECONNECToption with the -tafpolicy parameter is
deprecated.
SRVCTL Command Reference
A comprehensive list of SRVCTL commands to use in Oracle RAC environments.
SRVCTL commands, object names, and parameters are case sensitive. Database,
instance, listener, and service names are case insensitive and case preserving. You
cannot create listener names that differ only in case, such as LISTENER and listener.
SRVCTL uses the following command syntax:
srvctl command object [parameters]
In SRVCTL syntax:
•
command is a verb such as start, stop, or remove
•
object (also known as a noun) is the target or object on which SRVCTL performs
the command, such as database or instance. You can also use object abbreviations.
•
parameters extend the use of a preceding command combination to include
additional parameters for the command. For example, the -instances
parameter indicates that a comma-delimited list of preferred instance names
follows; the -instance parameter only permits one value and not a list of
names. Do not use spaces between the items in a comma-delimited list.
Note:
If specifying a comma-delimited list in Windows, then you must enclose the
list within double quotation marks ("").
Table A-4 lists the keywords that can be used for the object portion of SRVCTL
commands. You can use either the full name or the abbreviation for each object
A-16 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
keyword. The Purpose column describes the object and the actions that can be
performed on that object.
Table A-4
Object Keywords and Abbreviations
Object
Keyword
Purpose
Database
database
To add, modify, manage environment variables
for, list the configuration of, enable, disable,
start, stop, and obtain the status of databases,
and also to upgrade, downgrade, and remove
database configuration information about
databases.
Instance
instance
inst
Listener
listener
lsnr
Network
network
To add, modify, enable, disable, start, stop,
obtain the status of, and remove database
instances.
To add, modify, manage environment variables
for, list the configuration of, enable, disable,
start, stop, obtain the status of, and remove
listeners
To add, modify, list the configuration of, and
remove a non-default Network
Note: The node applications object, and the
config and modify commands also manage
the default network.
Node applications
nodeapps
To add, modify, manage environment variables
for, list the configuration of, enable, disable,
start, stop, obtain the status of, and remove node
applications
Oracle Notification
Service
ons
To add, configure, enable, start, obtain the status
of, stop, disable, and remove Oracle Notification
Service instances only for Oracle Restart
Single client access
name (SCAN)
scan
To add, list the configuration of, modify, enable,
disable, start, stop, relocate, obtain the status of,
and remove SCAN VIPs
SCAN listener
scan_listener
To add, list the configuration of, modify, enable,
disable, start, stop, relocate, obtain the status of,
and remove SCAN listeners
Service
Virtual IP
service
To add, modify, list the configuration of, enable,
disable, start, stop, obtain the status of, relocate,
and remove services
vip
To add, manage environment variables for, list
the configuration of, enable, disable, start, stop,
obtain the status of, and remove a VIP
srvctl add database
Adds a database configuration to Oracle Clusterware.
Server Control Utility Reference A-17
SRVCTL Command Reference
Syntax
srvctl add database -db db_unique_name [-eval]
-oraclehome oracle_home [-node node_name] [-domain domain_name]
[-spfile spfile] [-pwfile password_file_path]
[-dbtype {RACONENODE | RAC | SINGLE} [-server "server_list"]]
[-instance instance_name] [-timeout timeout]]
[-role {PRIMARY | PHYSICAL_STANDBY | LOGICAL_STANDBY | SNAPSHOT_STANDBY"]
[-startoption start_options] [-stopoption stop_options] [-dbname db_name]
[-acfspath "acfs_path_list"] [-policy {AUTOMATIC | MANUAL | NORESTART}]
[-serverpool "server_pool_list" [-pqpool "pq_pool_list"]]
[-diskgroup "disk_group_list"] [-css_critical {yes | no}] [-cpucount
cpu_count]
[-memorytarget memory_target] [-maxmemory max_memory] [-cpucap cpu_cap] [defaultnetnum network_number] [-verbose]
Parameters
Table A-5
srvctl add database Command Parameters
Parameter
Description
-db db_unique_name
Specify the unique name of the database.
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
Note: You can only use this parameter with a policy-managed
database.
-oraclehome
oracle_home
Specify the path for the Oracle database home directory.
-node node_name
Specify the node name on which you want to register a noncluster,
or single instance, Oracle database.
Note: This parameter can be used only with Oracle Clusterware
and can be used with the -serverpool parameter to create a
policy-managed, noncluster database.
-domain db_domain
Specify the domain for the database.
Note: You must use this parameter if you set the DB_DOMAIN
initialization parameter for the database.
-spfile spfile
Specify the path name of the database server parameter file.
-pwfile
password_file_path
Enter the full path to the location of the password file.
-dbtype
{RACONENODE | RAC
| SINGLE}
Specify the type of database you are adding: Oracle RAC One
Node, Oracle RAC, or single instance. The default is RAC unless
you specify the -node node_name parameter, and the -type
parameter defaults to SINGLE.
-server
server_list
List candidate servers for Oracle RAC One Node databases.
Note: You can use this parameter only with administratormanaged Oracle RAC One Node databases. If your Oracle RAC
One Node database is policy managed, then you cannot use this
parameter.
A-18 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-5
(Cont.) srvctl add database Command Parameters
Parameter
Description
-instance
instance_name
Specify the instance name prefix for Oracle RAC One Node
databases. The default value for this parameter is the first 12
characters of the global unique name of the database.
Note: You can use this parameter only with administratormanaged Oracle RAC One Node databases. If your Oracle RAC
One Node database is policy managed, then you cannot use this
parameter.
-timeout timeout
Specify the online database relocation timeout, in minutes, for
Oracle RAC One Node databases. The default is 30.
-role {PRIMARY |
PHYSICAL_STANDBY |
LOGICAL_STANDBY |
SNAPSHOT_STANDBY}
Specify the role of the database in an Oracle Data Guard
configuration. The default is PRIMARY.
-startoption
start_options
Startup options for the database, such as OPEN, MOUNT, and
NOMOUNT. The default value is OPEN.
Notes:
•
For multi-word startup options, such as read only and
read write, separate the words with a space and enclose in
double quotation marks (""). For example, "read only".
•
When performing a switchover in an Oracle Data Guard
configuration, the -startoption for a standby database
that becomes a primary database is always set to OPEN after
the switchover.
-stoption
stop_options
Specify stop options for the database, such as NORMAL,
TRANSACTIONAL, IMMEDIATE, and ABORT.
-dbname db_name
Specify the name of the database, if it is different from the unique
name given by the -db parameter.
-acfspath
"acfs_path_list"
A single Oracle ACFS path or a comma-delimited list of Oracle
ACFS paths enclosed in double quotation marks ("") where the
database's dependency is set.
Use this parameter to create dependencies on Oracle ACFS file
systems other than ORACLE_HOME, such as for when the database
uses ORACLE_BASE on a file system that is different from the
ORACLE_HOME file system.
Server Control Utility Reference A-19
SRVCTL Command Reference
Table A-5
(Cont.) srvctl add database Command Parameters
Parameter
Description
-policy {AUTOMATIC
| MANUAL |
NORESTART}
Specify the management policy for the database.
•
AUTOMATIC (default): The database is automatically restored
to its previous running condition (started or stopped) upon
restart of the database host computer.
•
MANUAL: The database is never automatically restarted upon
restart of the database host computer. A MANUAL setting does
not prevent Oracle Clusterware from monitoring the
database while it is running and restarting it if a failure
occurs.
•
NORESTART: Similar to the MANUAL setting, the database is
never automatically restarted upon restart of the database
host computer. A NORESTART setting, however, never
restarts the database even if a failure occurs.
-serverpool
"server_pool_name"
[-pqpool
"pq_pool_name"]
Specify the name of a server pool used to control database
placement. If you do not specify this parameter, then it defaults to
the Generic server pool.
You can optionally also specify the name of a parallel query server
pool to be used by the database.
Notes:
•
This parameter can only be used with Oracle Clusterware.
You can use this parameter with the -node parameter but
the server pool must have MAX_SIZE=1 and exactly one
configured server (the one you specify in -node).
•
After you add server pools, you can assign services to them
using the srvctl add service command.
-diskgroup
"disk_group_list"
Specify a comma-delimited list of Oracle ASM disk groups if
database uses Oracle ASM storage.
-css_critical {YES
| NO}
You can add weight to a service by setting this parameter to YES.
In the event of a node failure within the cluster, Oracle
Clusterware will evict the node with the least amount of weight,
ensuring that critical services remain available.
Note: You can use this parameter only on an administratormanaged node. Should the node become policy managed, at some
point, this parameter will no longer apply.
-cpucount
cpu_count
Specify the number of CPUs. The default value is 0.
-memorytarget
memory_target
Specify the target memory, in MB, to be allocated for the database.
The default is 0.
-maxmemory
max_memory
Specify the maximum memory, in MB, to be allocated for the
resource. If you specify -memorytarget but not -maxmemory,
then -maxmemory will be the default value of 0. Both maxmemory and -memorytarget are validated as long as memorytarget is less than or equal to -maxmemory.
A-20 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-5
(Cont.) srvctl add database Command Parameters
Parameter
Description
-cpucap cpu_cap
Specify a percentage from 1 to 100 that is the maximum utilization
of the workload CPUs the database requires. The default is 0.
-defaultnetnum
network_number
Specify a network number (an integer) to which services will
default in the event you do not specify a network number when
you add the service. The number must match the value of the netnum parameter you specified when you added the network.
Examples
An example of this command to add a policy-managed Oracle RAC database is:
$ srvctl add database -db crm -oraclehome /u01/oracle/product/12c/mydb
-domain example.com -spfile +diskgroup1/crm/spfilecrm.ora
-role PHYSICAL_STANDBY -startoption MOUNT -dbtype RAC -dbname crm_psd
-policy MANUAL -serverpool "svrpool1,svrpool2" -diskgroup "dgrp1,dgrp2"
An example of this command to add an administrator-managed database is:
$ srvctl add database -db crm -oraclehome /u01/oracle/product/12c/mydb
-domain example.com
srvctl config database
Displays the configuration for an Oracle RAC database or lists all configured
databases that are registered with Oracle Clusterware.
Syntax
srvctl config database [-db db_unique_name] [-all] [-verbose]
Parameters
Table A-6
srvctl config database Command Parameters
Parameter
-db db_unique_name
-all
-verbose
Description
Unique name for the database. If you do not specify this
parameter, then the utility displays the configuration of all
database resources.
Print detailed configuration information.
Display verbose output.
Example
This command returns output similar to the following:
$ srvctl config database -d main4
Server Control Utility Reference A-21
SRVCTL Command Reference
Database unique name: main
Database name:
Oracle home: /ade/mjkeenan_main4/oracle
Oracle user: mjkeenan
Spfile:
Password file:
Domain:
Start options: open
Stop options: immediate
Database role: PRIMARY
Management policy: AUTOMATIC
Server pools:
Disk Groups:
Mount point paths:
Services: test
Type: RAC
Start concurrency:
Stop concurrency:
OSDBA group: dba
OSOPER group: oper
Database instances: main41,main42
Configured nodes: mjkeenan_main4_0,mjkeenan_main4_1
CSS critical: no
CPU count: 0
Memory target : 0
Maximum memory: 0
CPU cap: 0
Database is administrator managed
srvctl convert database
Converts a database either to or from an Oracle RAC One Node database.
Syntax
Use this command with one of the following syntax models:
srvctl convert database -db db_unique_name -dbtype RACONENODE
[-instance instance_name] [-timeout timeout]
srvctl convert database -db db_unique_name -dbtype RAC [-node node_name]
Parameters
Table A-7
srvctl convert database Command Parameters
Parameter
Description
-db db_unique_name
Specify the unique name for the database.
Note: If you specify a noncluster database, then command returns
an error instructing you to use rconfig to convert the noncluster
database to Oracle RAC or Oracle RAC One Node.
A-22 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-7
(Cont.) srvctl convert database Command Parameters
Parameter
Description
-dbtype RACONENODE
| RAC
Specify the type of database to which you are converting, either
Oracle RAC One Node or Oracle RAC.
Note: If there is an ongoing or failed online database relocation,
then the command returns an error instructing you to first
complete or abort the online database relocation and then rerun
the command.
-instance
instance_name
Optionally, you can specify an instance name prefix for Oracle
RAC One Node databases. The default value for this parameter is
the first 12 characters of the global unique name of the database.
Notes:
•
•
You can use this parameter only when converting from an
Oracle RAC database to an Oracle RAC One Node database.
In order for the converted instance to come online, you must
restart the database using the srvctl stop/start
database commands.
-timeout timeout
Optionally, you can specify online database relocation timeout, in
minutes, for Oracle RAC One Node databases. The default is 30.
-node node_name
Optionally, you can specify the name of the node for an
administrator-managed Oracle RAC database. The default is the
first candidate.
Note: If you do not specify a node name or you specify a node
name where the database is not running, then the command
returns an error instructing you specify the correct node.
Example
An example of this command is:
$ srvctl convert database -db myDB -dbtype RACONENODE -instance myDB3
srvctl disable database
Disables a database. If the database is a cluster database, then its instances are also
disabled.
Syntax and Parameters
Use the srvctl disable database command with the following syntax:
srvctl disable database -db db_unique_name [-node node_name]
Table A-8
srvctl disable database Parameters
Parameter
-db database_name
Description
Database name
Server Control Utility Reference A-23
SRVCTL Command Reference
Table A-8
(Cont.) srvctl disable database Parameters
Parameter
Description
-node node_name
Disables the database from running on the named node.
Note: This parameter can be used only with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl disable database -db mydb1
srvctl disable diskgroup
Disables a specific disk group on a number of specified nodes.
Syntax and Parameters
Use the srvctl disable diskgroup command with the following syntax:
srvctl disable diskgroup -diskgroup diskgroup_name [-node "node_list"]
Table A-9
srvctl disable diskgroup Parameters
Parameter
-diskgroup diskgroup_name
-node "node_list"
Description
The Oracle ASM disk group name.
Comma-delimited list of node names on which to
disable the disk group
This parameter is only available with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl disable diskgroup -diskgroup dgroup1 -node "mynode1,mynode2"
srvctl add instance
Adds a configuration for an instance to your cluster database configuration.
You can only use this command for administrator-managed databases. If you have a
policy-managed database, then use the srvctl modify srvpool command to add an
instance to increase either the maximum size, minimum size, or both, of the server
pool used by the database.
Syntax
srvctl add instance -db db_unique_name -instance instance_name
-node node_name [-force]
A-24 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Parameters
Table A-10
srvctl add instance Command Parameters
Parameter
Description
-db db_unique_name
The unique name of the database you are adding the instance to
-instance
instance_name
The name of the instance you are adding
-node node_name
The name of the node on which you are creating the instance
-force
Optionally, you can force the add operation, even though some
resources will be stopped.
Usage Notes
•
This command increments the CARDINALITY resource attribute.
•
This command is only available with Oracle Clusterware and Oracle RAC.
•
If you attempt to use this command on an Oracle RAC One Node database, then
the command returns an error stating you must convert the database to Oracle
RAC.
Examples
Examples of this command are:
$ srvctl add instance -db crm -instance crm01 -node gm01
$ srvctl add instance -db crm -instance crm02 -node gm02
$ srvctl add instance -db crm -instance crm03 -node gm03
srvctl disable instance
Disables an instance. If the instance that you disable with this command is the last
enabled instance, then this operation also disables the database.
Note:
•
This command is only available with Oracle Clusterware and Oracle
RAC.
•
If you run this command on an Oracle RAC One Node database, then the
command returns an error instructing you to use the database noun,
instead.
Syntax and Parameters
Use the srvctl disable instance command with the following syntax:
srvctl disable instance -db db_unique_name -instance instance_name_list
Server Control Utility Reference A-25
SRVCTL Command Reference
Table A-11
srvctl disable instance Parameters
Parameter
-db db_unique_name
-instance instance_name_list
Description
Unique name for the database
Comma-delimited list of instance names
Example
An example of this command is:
$ srvctl disable instance -db crm -instance "crm1,crm3"
srvctl add listener
Adds a listener to every node in a cluster.
Syntax
Use this command with one of the following syntax models.
To create an Oracle Database listener:
srvctl add listener [-listener listener_name] [-netnum network_number] [-oraclehome
Oracle_home]
-user user_name [-endpoints "[TCP:]port_list[:FIREWALL={ON|OFF}][/IPC:key][/
NMP:pipe_name]
[/{TCPS|SDP|EXADIRECT}port_list[:FIREWALL={ON|OFF}]]" [-group group_name]] [invitednodes "node_list"]
[-invitedsubnets "subnet_list"] [-skip]
To create an Oracle ASM listener:
srvctl add listener [-listener listener_name] -asmlistener [-subnet subnet]
[-endpoints "[TCP:]port_list[:FIREWALL={ON|OFF}][/IPC:key][/NMP:pipe_name]
[/{TCPS|SDP|EXADIRECT}port_list[:FIREWALL={ON|OFF}]]" [-group group_name]] [invitednodes "node_list"]
[-invitedsubnets "subnet_list"] [-skip]
To create a Leaf listener:
srvctl add listener [-listener listener_name] -leaflistener [-subnet subnet]
[-endpoints "[TCP:]port_list[:FIREWALL={ON|OFF}][/IPC:key][/NMP:pipe_name]
[/{TCPS|SDP|EXADIRECT}port_list[:FIREWALL={ON|OFF}]]" [-group group_name]] [invitednodes "node_list"]
[-invitedsubnets "subnet_list"] [-skip]
To create a SCAN listener, use the srvctl add scan_listener command.
A-26 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Parameters
Table A-12
srvctl add listener Command Parameters
Parameter
Description
-listener
listener_name
Specify a listener name. This parameter is optional.
-netnum
network_number
The optional network number from which VIPs are obtained. If
not specified, the VIPs are obtained from the same default
network from which the nodeapps VIP is obtained.
If you do not specify this parameter, then the name of the listener
defaults to LISTENER for a database listener, LISTENER_ASM for
an Oracle ASM listener, and LISTENER_LEAF for a Leaf Node
listener.
Note: Use this parameter when you add an Oracle Database
listener.
-oraclehome
oracle_home
Specify an Oracle home for the cluster database. If you do not
include this parameter, then SRVCTL uses the Grid home by
default.
Note: Use this parameter when you add an Oracle Database
listener.
-user user_name
Use this parameter to set the user that will run the listener to a less
privileged user. Oracle recommends using this parameter to
increase security.
Notes:
•
•
•
You must be logged in as root to run this command and
specify the -user parameter.
Use this parameter when you add an Oracle Database
listener.
When you use the -user parameter, ensure the following:
The listener log directory in ORACLE_BASE and the
Grid_home/network/admin/user_name directory
must both exist on each node before you can use this
parameter. Additionally, user_name must have read, write,
and execute permission in the directory.
The $ORACLE_HOME/network/admin/
endpoints_listener.ora file exists and user_name
has read and write permission on it.
•
The $ORACLE_BASE/diag/tnslsnr/host_name/
lower_case_listener_name directory exists and
user_name has read, write, and execute permission on it.
Before you can use LSNRCTL to manage a listener, you must
set TNS_ADMIN to Grid_home/network/admin/
user_name.
Server Control Utility Reference A-27
SRVCTL Command Reference
Table A-12
(Cont.) srvctl add listener Command Parameters
Parameter
Description
-endpoints
"[TCP:]port_list[:
FIREWALL={ON|OFF}]
[/IPC:key] [/
NMP:pipe_name][/
{TCPS|SDP|
EXADIRECT}port_lis
t[:FIREWALL={ON|
OFF}]]"]
Protocol specifications for the listener. Use port_list to specify
a comma-delimited list of TCP ports or listener endpoints.
-group group_name
Optionally, you can use the -group parameter with -endpoints
to specify a group for the secure endpoint.
-invitednodes
"node_list"
Specify a comma-delimited list of node names allowed to register
with the listener.
-invitedsubnets
"subnet_list"
Specify a comma-delimited list of subnets allowed to register with
the listener.
-skip
Indicates you want to skip the checking of ports.
-asmlistener
Specifies the listener type as an Oracle ASM listener. If you do not
specify the -listener parameter, then the name of the Oracle
ASM listener defaults to LISTENER_ASM.
If you do not specify the -endpoints parameter for an Oracle
Database listener, then SRVCTL searches for a free port between
1521 and 1540.
You can also specify endpoints for TCPS, SDP, and EXADIRECT
ports.
Note: You can modify this attribute using Online Resource
Attribute Modification.
Note: You can only use this parameter with Oracle Clusterware.
-leaflistener
Specifies the listener type is a Leaf Node listener. If you do not
specify the -listener parameter, then the name of the Leaf
Node listener defaults to LISTENER_LEAF.
Note: You can only use this parameter with Oracle Clusterware.
-subnet subnet
Specifies the subnet to use for an Oracle ASM or Leaf Node
listener.
Note: You can only use this parameter with Oracle Clusterware.
Usage Notes
You must run this command as root user on Linux and UNIX platforms when you
specify the -user parameter.
Example
The following command adds a listener named listener112 that is listening on
ports 1341, 1342, and 1345 and runs from the Oracle home directory on every node in
the cluster:
$ srvctl add listener -listener listener112 -endpoints "1341,1342,1345"
-oraclehome /u01/app/oracle/product/12.2.0/db1
A-28 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
srvctl disable listener
Disables a listener resource.
Syntax and Parameters
Use the srvctl disable listener command with the following syntax:
srvctl disable listener [-listener listener_name] [-node node_name]
Table A-13
srvctl disable listener Parameters
Parameter
Description
-listener listener_name
Name of a listener resource. If you do not specify this
parameter, the name of the listener defaults to LISTENER.
-node node_name
Name of a cluster node on which the listener you want to
disable is running.
This parameter is only available with Oracle Clusterware.
Example
To disable the listener named listener_crm on the node node5, use this command:
$ srvctl disable listener -listener listener_crm -node node5
srvctl config listener
Displays configuration information of a specific listener that is registered with Oracle
Clusterware.
Syntax
srvctl config listener [-listener listener_name | -asmlistener | -leaflistener]
[-all]
Parameters
Table A-14
srvctl config listener Command Parameters
Parameter
Description
-listener listener_name | asmlistener | -leaflistener
The name of a specific listener name or the type of listener (Oracle ASM
or Leaf Node).
If you do not specify this parameter, then SRVCTL displays the
configuration for the default database listener.
Print detailed configuration information.
-all
Example
This command returns output similar to the following:
Name: LISTENER_LEAF
Subnet: 10.100.200.195
Type: type
Server Control Utility Reference A-29
SRVCTL Command Reference
Owner: scott
Home: Grid_home
End points: TCP:1521
srvctl add network
Adds a static or dynamic network.
If your server connects to more than one network, then you can use this command to
configure an additional network interface for Oracle RAC, allowing you to create VIPs
on multiple public networks.
Syntax
srvctl add network [-netnum net_number] -subnet subnet/netmask[/if1[|if2|...]]
[-nettype {static | dhcp | autoconfig | mixed}]
[-leaf] [-pingtarget "ping_target_list"] [-verbose]
Parameters
Table A-15
srvctl add network Command Parameters
Parameter
Description
-netnum net_number
Specify a network number. The default is 1.
-subnet subnet/netmask
[/if1[|if2|...]]
Defines a subnet. If you do not specify any interface names, then the network
uses any interface on the given subnet.
For IPv6, netmask is a prefix length, such as 64.
-nettype {static|dhcp|
autoconfig|mixed}
Specify the network type: static, dhcp, autoconfig, or mixed.
If you specify static for the network type, then you must provide the virtual
IP address using the srvctl add vip command.
If you specify dhcp for the network type, then the VIP agent obtains the IP
address from a DHCP server.
If you specify autoconfig for the network type, then the VIP agent generates a
stateless IPv6 address for the network. You can only use autoconfig for IPv6
networks. If the subnet/netmask specification is not for an IPv6 address, then
SRVCTL returns an error.
If you specify mixed for the network type, then the VIP resource uses both a
static IP address and an IP address obtained dynamically, either from a DHCP
server for IPv4 or using stateless autoconfiguration for IPv6.
-leaf
Specify the -leaf parameter when you want to create an application VIP
network resource that runs only on Leaf Nodes and is used by application VIPs.
[-pingtarget
"ping_target_list"]
Specify a comma-delimited list of IP addresses or host names to ping.
-verbose
Verbose output.
A-30 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Usage Notes
•
On Linux and UNIX systems, you must be logged in as root and on Windows,
you must be logged in as a user with Administrator privileges to run this
command.
•
This command is only available with Oracle Clusterware.
•
Oracle only supports DHCP-assigned networks for the default network, not for
subsequent networks.
•
You can also use the LISTENER_NETWORKS database initialization parameter to
control client redirects to the appropriate network.
Example
An example of this command is:
# srvctl add network -netnum 3 -subnet 192.168.3.0/255.255.255.0
srvctl config network
Displays the network configuration for the cluster.
Syntax
srvctl config network [-netnum network_number]
Usage Notes
•
Specify the network for which you want to display configuration information.
•
This command is only available with Oracle Clusterware.
Example
An example of this command is:
$ srvctl config network -netnum 2
srvctl add nodeapps
Adds a node application configuration to the specified node.
Syntax
Use this command with one the following syntax models, specifying either a specific
node and VIP or a specific subnet and netmask:
srvctl add nodeapps
{-node node_name -address {vip_name | ip_address}/netmask[/if1[|if2|..]] [-skip]}
[-emport em_port] [-onslocalport ons_local_port]
[-onsremoteport ons_remote_port] [-onshostport hostname_port_list]
[-remoteservers hostname_port_list [-verbose]
srvctl add nodeapps -subnet subnet/netmask[/if1[|if2|...]] [-emport em_port]
[-onslocalport ons_local_port] [-onsremoteport ons_remote_port]
[-onshostport hostname_port_list] [-remoteservers hostname_port_list]
[-verbose]
Server Control Utility Reference A-31
SRVCTL Command Reference
Parameters
Table A-16
srvctl add nodeapps Command Parameters
Parameter
Description
-node node_name
The name of the node on which you want to create the node application. Node
name is optional and unnecessary if you run the command on the local node.
-address {vip_name |
ip_address}/netmask[/
if1[|if2|..]]}
This specification creates a traditional VIP node application on the specified
node.
-skip
Specify this parameter to skip checking the reachability of the VIP address.
-subnet subnet/netmask
[/if1[|if2 |...]]
Creates a DHCP subnet. If you do not specify any interface names, then the VIPs
use any interface on the given subnet.
-emport em_port
Local port on which Oracle Enterprise Manager listens. The default port is 2016.
-onslocalport
ons_local_port
The Oracle Notification Service daemon listener port on its node.
Note: You must use this parameter for upgrade configurations and new, nonDHCP configurations.
If you do not specify this value, the Oracle Notification Service daemon listener
port defaults to 6100.
Note: The local port and remote port must each be unique.
The port number for remote Oracle Notification Service daemon connections.
-onsremoteport
ons_remote_port
If you do not specify a port number, the default value of 6200 is used for the
Oracle Notification Service remote port.
Note: The local port and remote port must each be unique.
A list of host[:port] pairs of remote hosts that are part of the Oracle
Notification Service network but are not part of the Oracle Clusterware cluster
-onshostport
host_port_list
Note: If port is not specified for a remote host, then ons_remote_port is
used.
-remoteservers
host_port_list
A list of host[:port] pairs for Oracle Notification Service daemons on servers
that are not in the cluster.
-verbose
Verbose output
Usage Notes
•
On Linux and UNIX systems, you must be logged in as root and on Windows,
you must be logged in as a user with Administrator privileges to run this
command.
•
This command is only available with Oracle Clusterware.
Example
An example of this command is:
# srvctl add nodeapps -node crmnode1 -address 1.2.3.4/255.255.255.0
A-32 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
srvctl config nodeapps
Displays the VIP configuration for each node in the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax
srvctl config nodeapps [-viponly] [-onsonly]
Usage Notes
Use -viponly to display the VIP address configuration. Use -onsonly to display the
Oracle Notification Service configuration.
Example
An example of this command is:
$ srvctl config nodeapps -viponly -onsonly
srvctl disable nodeapps
Disables node applications on all nodes in the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl disable nodeapps command with the following syntax:
srvctl disable nodeapps [-gsdonly] [-adminhelper] [-verbose]
Table A-17
srvctl disable nodeapps Parameters
Parameter
Description
-gsdonly
-adminhelper
-verbose
Disables GSD
Disable the Administrator helper only
Verbose output
Example
An example of this command is:
$ srvctl disable nodeapps -gsdonly -verbose
Server Control Utility Reference A-33
SRVCTL Command Reference
srvctl add ons
Adds an Oracle Notification Service daemon to an Oracle Restart configuration.
Syntax
srvctl add ons [-l ons_local_port] [-r ons_remote_port]
[-t host[:port][,host[:port]][...]] [-v]
Parameters
Table A-18
srvctl add ons Command Parameters
Parameter
Description
-l ons_local_port
The Oracle Notification Service daemon listening port for local client
connections
Note: The local port and remote port must each be unique.
The Oracle Notification Service daemon listening port for connections from
remote hosts
-r ons_remote_port
Note: The local port and remote port must each be unique.
A list of comma-delimited host:port pairs of remote hosts that are part of the
Oracle Notification Service network but are not part of the Oracle Clusterware
cluster
-t host[:port]
[,host[:port]][...]
Note: If port is not specified for a remote host, then ons_remote_port is
used.
Verbose output
-v
Usage Notes
This command is only available with Oracle Restart.
Example
An example of this command is:
$ srvctl add ons -l 6200
srvctl config ons
Displays configuration information for the Oracle Notification Service daemon.
Note:
This command is only available with Oracle Restart.
srvctl config ons
This command has no parameters.
A-34 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
srvctl disable ons
Disables the Oracle Notification Service daemon for Oracle Restart installations.
srvctl disable ons [-verbose]
The only parameter for this command is -verbose, which indicates that verbose
output should be displayed.
srvctl config qosmserver
Displays configuration information for the qosmserver resource.
Note: This command is only available with Oracle Clusterware.
Syntax
srvctl config qosmserver
Parameters
This command has no parameters.
Example
The following command displays the configuration information for the qosmserver
resource.
$ srvctl config qosmserver
srvctl add scan
Adds Oracle Clusterware resources for the given SCAN.
Syntax
srvctl add scan -scanname scan_name [-netnum network_number]
Parameters
Table A-19
srvctl add scan Command Parameters
Parameter
Description
-scanname scan_name
A fully-qualified host name, which includes the domain name. If the network is
dynamic, then you do not have to use fully-qualified host name but, if you
choose to do so, then the domain must be the GNS subdomain.
Note: You can modify this attribute using Online Resource Attribute
Modification.
-netnum network_number
The optional network number from which SCAN VIPs are obtained. If you do
not specify this parameter, then the SCAN VIPs are obtained from the same
default network from which the nodeapps VIP is obtained.
Server Control Utility Reference A-35
SRVCTL Command Reference
Usage Notes
•
This command creates the same number of SCAN VIP resources as the number of
IP addresses that SCAN resolves to, or 3 when network_number identifies a
dynamic network and Oracle GNS configuration.
•
For static networks, the addresses to which the SCAN resolves in DNS must
match the address type of the subnet.
•
For an IPv4 network, the SCAN must resolve to IPv4 addresses.
•
This command is only available with Oracle Clusterware.
Example
An example of this command is:
# srvctl add scan -scanname scan.mycluster.example.com
srvctl config scan
Displays the configuration information for all SCAN VIPs, by default, or a specific
SCAN VIP identified by ordinal_number.
Syntax
srvctl config scan [[-netnum network_number] [-scannumber ordinal_number] | -all]
Parameters
Table A-20
srvctl config scan Command Parameters
Parameter
Description
-netnum network_number
Use this parameter to view the configuration of a specific
SCAN VIP.
-scannumber
ordinal_number
Use this parameter to specify any one of the three SCAN
VIPs, using values from 1 to 3, for which you want to view
the configuration.
-all
Alternative to specifying network or ordinal numbers, you
can use this parameter to view the configuration for all of
the SCAN VIPs.
Usage Notes
This command is only available with Oracle Clusterware.
Example
This command returns output similar to the following:
$ srvctl config scan -scannumber 1
SCAN name: mjk12700890090-r, Network: 1
Subnet IPv4: 198.51.100.1/203.0.113.46/eth0, static
Subnet IPv6:
A-36 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
SCAN
SCAN
SCAN
SCAN
1 IPv4
VIP is
VIP is
VIP is
VIP: 198.51.100.195
enabled.
individually enabled on nodes:
individually disabled on nodes:
srvctl disable scan
Disables all SCAN VIPs, by default, or a specific SCAN VIP identified by
ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl disable scan command with the following syntax:
srvctl disable scan [-scannumber ordinal_number]
The only parameter available for this command is -scannumber ordinal_number,
which represents which identifies any one of the three SCAN VIPs, and can take a
range of values from 1 to 3.
Example
An example of this command is:
$ srvctl disable scan -scannumber 1
srvctl add scan_listener
Adds Oracle Clusterware resources for the SCAN listeners.
Syntax
srvctl add scan_listener [-listener lsnr_name_prefix] [-skip] [-netnum
network_number]
[-endpoints "[TCP:]port_list[:FIREWALL={ON|OFF}][/IPC:key][/NMP:pipe_name]
[/{TCPS|SDP|EXADIRECT}port_list[:FIREWALL={ON|OFF}]]" [-invitednodes node_list] [invitedsubnets subnet_list]
Parameters
Table A-21
srvctl add scan_listener Command Parameters
Parameter
Description
-listener
lsnr_name_prefix
The SCAN listener name prefix.
-skip
Use this parameter to skip checking of the ports.
-netnum network_number
The optional network number from which SCAN VIPs are obtained. If you do
not specify this parameter, then the SCAN VIPs are obtained from the same
default network from which the nodeapps VIP is obtained.
Server Control Utility Reference A-37
SRVCTL Command Reference
Table A-21
(Cont.) srvctl add scan_listener Command Parameters
Parameter
Description
-endpoints
"[TCP:]port_list[:FIRE
WALL={ON|OFF}][/
IPC:key] [/
NMP:pipe_name][/{TCPS|
SDP|
EXADIRECT}port_list[:F
IREWALL={ON|OFF}]]"]
Protocol specifications for the SCAN listener. Use port_list to specify a
comma-delimited list of TCP ports or SCAN listener endpoints.
You can also specify endpoints for TCPS, SDP, and EXADIRECT ports.
Note: You can modify this attribute using Online Resource Attribute
Modification.
-invitednodes
node_list
Use this parameter to specify a comma-delimited list of host names from outside
the cluster that are allowed to register with the SCAN listener.
-invitedsubnets
subnet_list
Use this parameter to specify a comma-delimited list of subnets from outside the
cluster that are allowed to register with the SCAN listener.
Usage Notes
•
The number of SCAN listener resources created is the same as the number of
SCAN VIP resources.
•
This command is only available with Oracle Clusterware.
Example
An example of this command is:
# srvctl add scan_listener -listener myscanlistener
srvctl config scan_listener
Displays the configuration information for all SCAN listeners, by default, or a specific
listener identified by network number or ordinal_number.
Syntax
srvctl config scan_listener [[-netnum network_number] [-scannumber ordinal_number] |
-all]
Parameters
Table A-22
srvctl config scan_listener Command Parameters
Parameter
Description
-netnum network_number
Use this parameter to view the configuration of the listener
for a specific SCAN VIP.
-scannumber
ordinal_number
Use this parameter to specify any one of the three SCAN
VIPs, using values from 1 to 3, for which you want to view
the configuration of the listener.
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Table A-22
(Cont.) srvctl config scan_listener Command Parameters
Parameter
Description
–all
Alternative to specifying network or ordinal numbers, you
can use this parameter to view the configuration of the
listeners for all of the SCAN VIPs.
Usage Notes
This command is only available with Oracle Clusterware.
Example
This command returns output similar to the following:
$ srvctl config scan_listener -scannumber 1
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1529
Registration invited nodes:
Registration invited subnets:
SCAN Listener is enabled.
SCAN Listener is individually enabled on nodes:
SCAN Listener is individually disabled on nodes:
srvctl disable scan_listener
Disables all SCAN listeners, by default, or a specific listener identified by
ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl disable scan_listener command with the following syntax:
srvctl disable scan_listener [-scannumber ordinal_number]
The only parameter available for this command is -scannumber ordinal_number,
which identifies any one of the three SCAN listeners, and can take a range of values
from 1 to 3.
Example
An example of this command is:
$ srvctl disable scan_listener -scannumber 1
srvctl add service
Adds services to a database and assigns them to instances.
Syntax
Use this command with one of the following syntax models.
Server Control Utility Reference A-39
SRVCTL Command Reference
To add a service to a policy-managed database:
srvctl add service -db db_unique_name -service service_name [-eval]
-serverpool server_pool [-pdb pluggable_database]
[-cardinality {UNIFORM | SINGLETON}] [-edition edition_name]
[-netnum network_number] [-role "[PRIMARY][,PHYSICAL_STANDBY][,LOGICAL_STANDBY]
[,SNAPSHOT_STANDBY]"]
[-policy {AUTOMATIC | MANUAL}] [-notification {TRUE | FALSE}] [-rfpool pool_name]
[-clbgoal {SHORT | LONG}] [-failovertype {NONE|SESSION|SELECT|TRANSACTION}]
[-rlbgoal {NONE | SERVICE_TIME | THROUGHPUT}] [-dtp {TRUE | FALSE}]
[-failovermethod {NONE | BASIC}] [-failoverretry failover_retries]
[-drain_timeout timeout] [-stopoption {NONE|IMMEDIATE|TRANSACTIONAL}]
[-failoverrestore {NONE|LEVEL1}] [-failoverdelay failover_delay]
[-gsmflags gsm_flags] [-sql_translation_profile sql_translation_profile]
[-global {TRUE | FALSE}] [-maxlag max_lag_time] [-commit_outcome {TRUE|FALSE}]
[-retention retention_time] [-replay_init_time replay_initiation_time]
[-session_state {STATIC | DYNAMIC}] [-pqservice pq_service]
[-pqpool pq_pool] [-css_critical {yes | no}] [-force]
To add a service to an administrator-managed database:
srvctl add service -database db_unique_name -service service_name
[-pdb pluggable_database] [-eval]
[-preferred preferred_list] [-available available_list]
[-netnum network_number] [-tafpolicy {BASIC | NONE}]
[-edition edition_name]
[-role "[PRIMARY][,PHYSICAL_STANDBY][,LOGICAL_STANDBY][,SNAPSHOT_STANDBY]"
[-policy {AUTOMATIC | MANUAL}] [-notification {TRUE | FALSE}]
[-clbgoal {SHORT | LONG}] [-failovertype {NONE|SESSION|SELECT|TRANSACTION}]
[-rlbgoal {NONE | SERVICE_TIME | THROUGHPUT}] [-dtp {TRUE | FALSE}]
[-failovermethod {NONE | BASIC}] [-failoverretry failover_retries]
[-drain_timeout timeout] [-stopoption {NONE|IMMEDIATE|TRANSACTIONAL}]
[-failoverrestore {NONE|LEVEL1}] [-failoverdelay failover_delay]
[-sql_translation_profile sql_translation_profile]
[-global {TRUE | FALSE}] [-maxlag max_lag_time] [-commit_outcome {TRUE|FALSE}]
[-retention retention_time] [-replay_init_time replay_initiation_time]
[-session_state {STATIC|DYNAMIC}] [-force] [-verbose]
To update the preferred and available lists of an existing service:
srvctl add service -db db_unique_name -service service_name
-update {-prefered preferred_list | -available available_list} [-force]
[-verbose]
Parameters
The following table lists and describes all the srvctl add service parameters and
whether they can be used when adding a service to either an Oracle RAC database or
noncluster database.
Table A-23
srvctl add service Command Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
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Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-service
service_name
The service_name.service_domain should be unique within
the cluster unless you want to spread connections across multiple
databases that offer the same service. If you do not specify the
service domain as part of the service name (such as
sales.example.com), then the DB_DOMAIN database attribute is
appended to the service name.
Note: The -service parameter has a 4 kilobyte (KB) limit for its
value. Therefore, the total length of the names of all services
assigned to an instance cannot exceed 4 KB.
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
Note: You can only use this parameter with a policy-managed
service.
-edition
edition_name
The initial session edition of the service.
When an edition is specified for a service, all subsequent
connections that specify the service use this edition as the initial
session edition. However, if a session connection specifies a
different edition, then the edition specified in the session
connection is used for the initial session edition.
SRVCTL does not validate the specified edition name. During
connection, the connect user must have USE privilege on the
specified edition. If the edition does not exist or if the connect user
does not have USE privilege on the specified edition, then an error
is raised.
sql_translation_pr
ofile profile_name
Use this parameter to specify a SQL translation profile for a
service that you are adding after you have migrated applications
from a non-Oracle database to an Oracle database.
This parameter corresponds to the SQL translation profile
parameter in the DBMS_SERVICE service attribute.
Notes:
•
Before using the SQL translation feature, you must migrate
all server-side application objects and data to the Oracle
database.
•
Use the srvctl config service command to display the
SQL translation profile.
-preferred
preferred_list
A list of preferred instances on which the service runs when the
database is administrator managed.
The list of preferred instances must be mutually exclusive with the
list of available instances.
Note: This parameter can be used only with Oracle RAC and only
for administrator-managed databases.
Server Control Utility Reference A-41
SRVCTL Command Reference
Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-available
available_list
A list of available instances to which the service fails over when
the database is administrator managed.
The list of available instances must be mutually exclusive with the
list of preferred instances.
Note: This parameter can be used only with Oracle RAC and only
for administrator-managed databases.
-serverpool
server_pool
The name of a server pool used when the database is policy
managed.
Note: This parameter can be used only with Oracle RAC and only
for policy-managed databases.
-cardinality
{UNIFORM |
SINGLETON}
The cardinality of the service, either UNIFORM (offered on all
instances in the server pool) or SINGLETON (runs on only one
instance at a time).
Notes:
•
This parameter can be used only with Oracle RAC and only
for policy-managed databases.
•
For policy-managed Oracle RAC One Node databases, all
services must be SINGLETON.
-netnum
network_number
Use this parameter to determine on which network this service is
offered. The service is configured to depend on VIPs from the
specified network.
Notes:
•
If you omit this parameter, then the default is taken from the
database configuration, which you specify using srvctl
add database or srvctly modify database, with the
-defaultnetwork parameter to specify the default network
for that database's services.
•
This parameter can be used only with Oracle RAC and Oracle
RAC One Node database configurations.
-tafpolicy {BASIC
| NONE}
TAF policy specification (for administrator-managed databases
only).
-role "[PRIMARY]
[,PHYSICAL_STANDBY
]
[,LOGICAL_STANDBY]
[,SNAPSHOT_STANDBY
]"
The service role. You can specify one or more roles in a commadelimited list.
Use this option to indicate that the service should only be
automatically started upon database open when the Oracle Data
Guard database role matches one of the specified service roles.
Using SRVCTL to manually start a service is not affected by the
service role.
Note: The -role parameter is only used at database startup and
by the Oracle Data Guard Broker. All manual service startup must
specify the name of the service to be started by the user.
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Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-policy {AUTOMATIC
| MANUAL}
Service management policy.
If AUTOMATIC (the default), then the service is automatically
started upon restart of the database, either by a planned restart
(with SRVCTL) or after a failure. Automatic restart is also subject
to the service role, however (the -role parameter).
If MANUAL, then the service is never automatically restarted upon
planned restart of the database (with SRVCTL). A MANUAL setting
does not prevent Oracle Clusterware from monitoring the service
when it is running and restarting it if a failure occurs.
Note: Using CRSCTL to stop and start the Oracle Clusterware
restarts the service in the same way that a failure does.
-notification
{TRUE | FALSE}
Enable Fast Application Notification (FAN) for OCI connections.
-rfpool pool_name
Specify the name of the reader farm server pool.
-dtp {TRUE |
FALSE}
Indicates whether Distributed Transaction Processing should be
enabled for this service. This service will either be a singleton
service in a policy-managed database or a preferred service on a
single node in an administrator-managed database.
Note: This parameter can be used only with Oracle RAC.
-clbgoal {SHORT |
LONG}
Connection Load Balancing Goal. Use a value of SHORT for this
parameter for run-time load balancing, or if using an integrated
connection pool. Use a value of LONG for this parameter for long
running connections, such as batch jobs, that you want balanced
by the number of sessions per node for the service.
-rlbgoal {NONE |
SERVICE_TIME |
THROUGHPUT}
Runtime Load Balancing Goal (for the Load Balancing Advisory).
Set this parameter to SERVICE_TIME to balance connections by
response time. Set this parameter to THROUGHPUT to balance
connections by throughput.
-failovertype
{NONE | SESSION |
SELECT |
TRANSACTION}
Failover type.
To enable Application Continuity for Java, set this parameter to
TRANSACTION. To enable TAF for OCI, set this parameter to
SELECT or SESSION.
Note: If you set -failovertype to TRANSACTION, then you
must set -commit_outcome to TRUE.
-failovermethod
{NONE | BASIC}
TAF failover method (for backward compatibility only).
If the failover type (-failovertype) is set to a value other than
NONE, then you should choose BASIC for this parameter.
Note: This parameter can be used only with Oracle RAC.
-failoverretry
failover_retries
For Application Continuity and TAF, this parameter determines
the number of attempts to connect after an incident.
Server Control Utility Reference A-43
SRVCTL Command Reference
Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-drain_timeout
timeout
Specify the time, in seconds, allowed for resource draining to be
completed. Accepted values are an empty string (""), 0, or any
positive integer. The default value is an empty string, which
means that this parameter is not set. If it is set to 0, then draining
occurs, immediately.
The draining period is intended for planned maintenance
operations. During the draining period, all current client requests
are processed, but new requests are not accepted. When set on the
service this value is used when the command line value is not set.
-stopoption {NONE|
IMMEDIATE|
TRANSACTIONAL}
Specify the mode in which the service is stopped. When set on the
service, this value is used if you do not set the value on the
command line.
IMMEDIATE permits sessions to drain before the service is
stopped.
TRANSACTIONAL permits sessions to drain for the amount of time
specified in the -drain_timeout parameter. The service is
stopped when the time limit is reached and any remaining
sessions are terminated.
If you specify NONE, then no sessions are terminated.
The default is taken from the service setting, when specified on
the service. Otherwise the default is NONE.
Note: You must use the -stopoption parameter with the force parameter.
-failoverrestore
{NONE|LEVEL1}
For Application Continuity, when you set the failoverrestore parameter, session states are restored before
replaying. Use LEVEL1 for ODP.NET and Java with Application
Continuity to restore the initial state.
For OCI applications using TAF or Application Continuity, setting
-failoverrestore to LEVEL1 restores the current state. If the
current state differs from the initial state, then a TAF callback is
required. This restriction applies only to OCI.
-failoverdelay
failover_delay
For Application Continuity and TAF, this parameter specifies the
time delay (in seconds) between reconnect attempts per incident
at failover.
-gsmflags
gsm_flags
Set locality and region failover values.
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Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-pdb
pluggable_database
The name of the pluggable database (PDB).
Note: You can specify a PDB property when you create or modify
a service. The PDB property associates the service with the
specified PDB. You can view the PDB property for a service by
querying the ALL_SERVICES data dictionary view or, when using
the SRVCTL utility, by running the srvctl config service
command.
When you create or modify a service with the specified PDB,
SRVCTL does not check if the PDB exists. Before running this
command, you must ensure that the PDB exists.
-global {TRUE |
FALSE}
Indicates whether this is a Global Data Services service.
-maxlag
maximum_lag_time
Maximum replication lag time in seconds. Must be a non-negative
integer. The default value is ANY.
-commit_outcome
{TRUE | FALSE}
Enable Transaction Guard; when set to TRUE, the commit outcome
for a transaction is accessible after the transaction's session fails
due to a recoverable outage.
-retention
retention_time
If -commit_outcome is set to TRUE, then this parameter
determines the amount of time (in seconds) that the commit
outcome is retained in the database.
-replay_init_time
replay_initializat
ion_time
For Application Continuity, this parameter specifies the difference
between the time, in seconds, of original execution of the first
operation of a request and the time that the replay is ready to start
after a successful reconnect. Application Continuity will not
replay after the specified amount of time has passed. This
parameter is intended to avoid the unintentional execution of a
transaction when a system is recovered after a long period. The
default is 5 minutes (300). The maximum value is 24 hours
(86400). If the -failover_type parameter is not set to
TRANSACTION, then you cannot use this parameter.
-session_state
{STATIC | DYNAMIC}
For Application Continuity, this parameter specifies whether the
session state that is not transactional is changed by the
application. Oracle recommends a setting of DYNAMIC for most
applications.
Note: This parameter can only be used with Global Data Services.
Note: This parameter is considered only if -failovertype is set
to TRANSACTION for Application Continuity. It describes how
non-transactional is changed during a request. Examples of
session state are NLS settings, optimizer preferences, event
settings, PL/SQL global variables, temporary tables, advanced
queues, LOBs, and result cache. If non-transactional values change
after the request starts, then use the default, DYNAMIC. Most
applications should use DYNAMIC mode. If you are unsure, then
use DYNAMIC mode.
Server Control Utility Reference A-45
SRVCTL Command Reference
Table A-23
(Cont.) srvctl add service Command Parameters
Parameter
Description
-pqservice
pq_service
Specify a parallel query service name.
-pqpool pq_pool
Specify a parallel query server pool.
-update {preferred
new_preferred_inst
ance | -available
new_available_inst
ance}
Add a new preferred or available instance to the service
configuration. -preferred specifies the name of the instance to
add to the list of preferred instances for the service. -available
specifies the name of the instance to add to the list of available
instances for the service.
-css_critical {yes
| no}
You can add weight to a service by setting this parameter to YES.
In the event of a node failure within the cluster, Oracle
Clusterware will evict the node with the least amount of weight,
ensuring that critical services remain available.
Note: You can use this parameter only on an administratormanaged node. Should the node become policy managed, at some
point, this parameter will no longer apply.
-verbose
Display verbose output.
-force
Force the add operation even though a listener is not configured
for a network.
Usage Notes
This command does not accept placement parameters for Oracle RAC One Node
databases.
Examples
Use this example syntax to add the gl.example.com service to the my_rac database
with Fast Application Notification enabled for OCI connections, a failover method of
BASIC, a Connection Load Balancing Goal of LONG, a failover type of SELECT, and 180
failover retries with a failover delay of 5 seconds:
$ srvctl add service -db my_rac -service gl.example.com -notification TRUE failovermethod BASIC -failovertype SELECT -failoverretry 180 -failoverdelay 5 clbgoal LONG
Use this example syntax to add a named service to a database with preferred instances
and available instances and enabled for TAF:
$ srvctl add service -db crm -service sales -preferred crm01,crm02 -available crm03 tafpolicy BASIC
srvctl config service
Displays the configuration for a service.
A-46 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Syntax
srvctl config service {-db db_unique_name [-service service_name]
| -serverpool pool_name [-db db_unique_name]} [-verbose]
Parameters
Table A-24
srvctl config service Command Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
-service service_name
Optionally, you can specify the name of a service.
If you do not use this parameter, then SRVCTL displays the configuration
information for all services configured for the database.
-serverpool pool_name
Alternatively, you can use this parameter to specify the name of a server pool
for which you want to view the service configuration. Optionally, you can also
specify a particular database on which the server pool resides.
-verbose
Displays verbose output.
Usage Notes
The srvctl config service command shows exactly the string value you
specified for the edition using the srvctl add | modify service commands. If
you specified the edition in upper case, then srvctl config service displays
upper case. If it is surrounded by double quotation marks (""), then the command
displays the double quotation marks. Otherwise, the command displays an empty
string.
Examples
This command returns information similar to the following for a policy-managed
database:
$ srvctl config service -db crm -service webapps
Service name: webapps
Service is enabled
Server pool: sales
Cardinality: SINGLETON
Disconnect: false
Service role: PRIMARY
Management policy: AUTOMATIC
DTP transaction: false
AQ HA notifications: false
Failover type: NONE
Failover method: NONE
TAF failover retries: 0
TAF failover delay: 0
Connection Load Balancing Goal: LONG
Runtime Load Balancing Goal: NONE
TAF policy specification: NONE
Service is enabled on nodes:
Service is disabled on nodes:
Edition: "my Edition"
Server Control Utility Reference A-47
SRVCTL Command Reference
This command returns information similar to the following for a administratormanaged database:
$ srvctl config service -db crm -service webapps
Service name: webapps
Service is enabled
Server pool: sales
Cardinality: 1
Disconnect: false
Service role: PRIMARY
Management policy: AUTOMATIC
DTP transaction: false
AQ HA notifications: false
Failover type: NONE
Failover method: NONE
TAF failover retries: 0
TAF failover delay: 0
Connection Load Balancing Goal: LONG
Runtime Load Balancing Goal: NONE
TAF policy specification: NONE
Preferred instances: crm_1
Available instances:
Edition: "my Edition"
Service configuration for administrator-managed Oracle RAC One Node databases
displays the one instance as preferred.
srvctl disable service
Disables a service. Disabling an entire service affects all of the instances, disabling each
one. When the entire service is already disabled, a srvctl disable service
operation on the entire service affects all of the instances and disables them; it just
returns an error. This means that you cannot always use the entire set of service
operations to manipulate the service indicators for each instance.
Syntax and Parameters
Use the srvctl disable service command with the following syntax:
srvctl disable service -db db_unique_name -servics "service_name_list"
[-instance instance_name | -node node_name]
If you do not specify either the -instance instance_name or -node node_name
parameters, then the command disables the service on all nodes.
Table A-25
srvctl disable service Parameters
Parameter
-database db_unique_name
-service "service_name_list"
Description
Unique name for the database.
Comma-delimited list of service names, or a single
service name
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Table A-25
(Cont.) srvctl disable service Parameters
Parameter
Description
-instance instance_name
The name of the instance for which you want to
disable the service.
Notes:
•
•
-node node_name
Use this parameter with administrator-managed
databases
This parameter can be used only with Oracle
Clusterware and Oracle RAC
The name of the node on which to disable the
service.
Notes:
•
•
Use this parameter with policy-managed
databases
This parameter can be used only with Oracle
Clusterware and Oracle RAC
Examples
The following example globally disables two services for the CRM database:
$ srvctl disable service -db crm -service "crm,marketing"
The following example disables a service for the CRM database that is running on the
CRM1 instance, resulting in the service still being available for the database, but on one
less instance:
$ srvctl disable service -db crm -service crm -instance crm1
srvctl add srvpool
Adds a server pool that is configured to host Oracle databases to a cluster.
Syntax
srvctl add srvpool -serverpool server_pool_name [-eval]
[-importance importance] [-min min_size] [-max max_size]
[-servers "node_list" | -category server_category] [-force] [-verbose]
Parameters
Table A-26
srvctl add srvpool Command Parameters
Parameter
Description
-serverpool
server_pool_name
The name of the server pool.
-eval
Use this parameter to hypothetically evaluate the impact of the command on the
system.
-importance importance
The importance of the server pool (default value is 0).
-min min_size
The minimum size of the server pool (default value is 0).
Server Control Utility Reference A-49
SRVCTL Command Reference
Table A-26
(Cont.) srvctl add srvpool Command Parameters
Parameter
Description
-max max_size
The maximum size of the server pool. The default value is -1, which indicates
that the size is unlimited.
-servers "node_list"
A comma-delimited list of candidate node names enclosed in double quotation
marks (""). The server pool will only include nodes on the candidate list, but
not all nodes on the candidate list will necessarily be in the server pool.
Note: In Oracle Database 12c, servers are assigned to server pools according to
the value of the -category parameter.
-category
server_category
The category of servers to use for the server pool, or "" for the empty category
value. You can use hub for ora.hub.category, leaf for
ora.leaf.category, or you can define your own category. The default is
ora.hub.category.
-force
Add the server pool, even if it requires stopping resources in other server pools.
-verbose
Display verbose output.
Usage Notes
•
SRVCTL prepends “ora.” to the name of the server pool.
•
This command is only available with Oracle Clusterware.
Example
The following command adds a server pool named SP1, with importance set to 1, the
minimum number of nodes in the server pool set to 3 and the maximum number of
nodes in the server pool set to 7:
srvctl add srvpool -serverpool SP1 -importance 1 -min 3 -max 7
srvctl config srvpool
Displays configuration information including name, minimum size, maximum size,
importance, and a list of server names, if applicable, for a specific server pool in a
cluster.
Syntax
srvctl config srvpool [-serverpool pool_name]
Parameters
The only parameter available for this command is -serverpool pool_name, which
is the name of the server pool for which you want to display the configuration
information.
Usage Notes
This command is only available with Oracle Clusterware.
A-50 Oracle Real Application Clusters Administration and Deployment Guide
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Example
An example of this command is:
$ srvctl config srvpool -serverpool dbpool
srvctl add vip
Adds a virtual IP address (VIP) to a node.
Syntax
srvctl add vip -node node_name -address {VIP_name|ip}/netmask[/if1[|if2|...]]
-netnum network_number [-skip] [-verbose]
Parameters
Table A-27
srvctl add vip Command Parameters
Parameter
Description
-node node_name
The name of the node on which you are adding the VIP.
-address {VIP_name|
ip}/netmask [/if1[|
if2|...]]
This specification creates a traditional VIP node application on the specified
node.
-netnum network_number
The network number from which VIPs are obtained. The default network
number is 1.
-skip
Specify this parameter to skip checking the reachability of the VIP address.
-verbose
Verbose output
You can specify one VIP_name or address, along with an IPv4 netmask or IPv6
prefix length.
Note:
Usage Notes
•
You cannot have multiple VIPs on the same net number (subnet or interface pair)
on the same node.
•
This command is only available with Oracle Clusterware.
Example
An example of this command is:
# srvctl add network -netnum 2 -subnet 192.168.16.0/255.255.255.0
# srvctl add vip -node node7 -address 192.168.16.17/255.255.255.0 -netnum 2
The first command creates a network number, 2, and the second command adds a VIP
to this network. You can specify the network number after the -netnum parameter in
other SRVCTL commands.
Server Control Utility Reference A-51
SRVCTL Command Reference
srvctl config vip
Displays all VIPs on all networks in the cluster except for user VIPs.
Syntax
srvctl config vip {-node node_name | -vip vip_name}
Parameters
Table A-28
srvctl config vip Command Parameters
Parameter
Description
-node node_name
Specify the node name.
-vip vip_name
Alternatively, you can specify the VIP name.
Usage Notes
This command is only available with Oracle Clusterware.
Example
This command returns output similar to the following:
$ srvctl config vip -node crmnode1
VIP exists: ipv4, ipv6, network number 1, hosting node adc2100252
srvctl disable vip
Disables a specific VIP.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl disable vip command with the following syntax:
srvctl disable vip -vip vip_name [-verbose]
Table A-29
srvctl disable vip Parameters
Parameter
-vip vip_name
-verbose
Description
The VIP name
Verbose output
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Example
An example of this command is:
$ srvctl disable vip -vip vip1 -verbose
srvctl config volume
Displays the configuration for a specific volume or all volumes.
Syntax
srvctl config volume [-volume volume_name] [-diskgroup disk_group_name]
[-device volume_device]
Parameters
Table A-30
srvctl config volume Command Parameters
Parameter
Description
-volume volume_name
Specify the name of the volume for which you want to view the
configuration.
-diskgroup
disk_group_name
Specify the name of the disk group in which the volume resides for which
you want to display the configuration.
-device volume_device
Specify the path to the volume device for which you want to display the
configuration.
Usage Notes
•
If you do not specify any of the optional parameters, then SRVCTL displays the
configuration information for all volumes.
•
If you specify only the -volume parameter, then SRVCTL displays the
configuration for all volumes with that name, regardless of the diskgroup.
•
If you specify only the -diskgroup parameter, then SRVCTL displays the
configuration information for the volumes that reside in the disk group that you
specify.
•
If you specify only the -device parameter, then SRVCTL displays the
configuration information for the volume matching that device specifier.
•
If you specify the -diskgroup and -device parameters, then SRVCTL displays
the configuration information for the volume device that resides in the disk group
that you specify.
•
This command is only available with Oracle Clusterware.
Examples
This command returns information similar to the following:
$ srvctl config volume -device /dev/asm/volume1-123
Server Control Utility Reference A-53
SRVCTL Command Reference
Diskgroup Name: DG1
Volume Name : VOL1
Volume Device : /dev/asm/volume1-123
Volume is enabled.
Volume is enabled on nodes:
Volume is disabled on nodes:
If you do not specify any parameters, then SRVCTL returns configuration information
for all volumes, similar to the following:
$ srvctl config volume
Diskgroup name: DG1
Volume name: VOL1
Volume device: /dev/asm/volume1-123
Volume is enabled.
Volume is enabled on nodes:
Volume is disabled on nodes:
Diskgroup name: DG1
Volume name: VOL2
Volume device: /dev/asm/volume2-456
Volume is enabled.
Volume is enabled on nodes:
Volume is disabled on nodes:
srvctl disable volume
Disables Oracle Clusterware management for a specific volume or all volumes.
This command allows a volume device to be stopped by operating on the Oracle
Clusterware resource for the volume. This command does not stop volume device.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl disable volume command with the following syntax:
srvctl disable volume {-volume volume_name -diskgroup disk_group_name |
-device volume_device}
Table A-31
srvctl disable volume Parameters
Parameter
Description
-volume volume_name
Specify the name of the volume that you want to
disable. This parameter is required.
-diskgroup disk_group_name
Specify the name of the disk group in which the
volume that you want to disable resides.
-device volume_device
Specify the path to the volume device that you
want to disable.
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Usage Notes
•
You must specify a particular volume that you want to disable. You can specify a
volume that resides in either a particular disk group or on a particular volume
device.
Example
The following example disables a volume named VOLUME1 that resides in a disk
group named DATA:
$ srvctl disable volume -volume VOLUME1 -diskgroup DATA
srvctl downgrade database
The srvctl downgrade database command downgrades the configuration of a
database and its services from its current version to the specified lower version.
Syntax and Parameters
Use the srvctl downgrade database command as follows:
srvctl downgrade database -db db_unique_name -oraclehome Oracle_home
-targetversion to_version
Table A-32
srvctl downgrade database Parameters
Parameter
-db db_unique_name
-oraclehome Oracle_home
-targetversion to_version
Description
Unique name for the database
The path to the ORACLE_HOME
The version to which to downgrade
enable
The srvctl enable command enables the specified object so that it can run under
Oracle Clusterware for automatic startup, failover, or restart.
The Oracle Clusterware application supporting the object may be up or down to use
this function. The default value is enable. If the object is already enabled, then
SRVCTL returns a message advising you that the object is enabled. Enabled objects can
be started, and disabled objects cannot be started.
When you run the enable command, the object is enabled and available to run under
Oracle Clusterware for automatic startup, failover, or restart. Additionally, you can
run the srvctl start command on an enabled object. If you specify -instance
instance_name or -node node_name, then SRVCTL only enables the object on the
specified instance or node.
If you do not specify -instance instance_name or -node node_name, then the
enable action applies to the object that you specified, globally, on all nodes in the
cluster and also removes any per-node enable settings. Any object you enable globally
is also enabled on any nodes you add to the cluster in the future.
Server Control Utility Reference A-55
SRVCTL Command Reference
Enabling an object globally is different from enabling an object, individually, on each
node in the cluster. For example, if you enable a database on several nodes,
individually, in a cluster, then, when you run the srvctl start database
command, the database starts only on nodes where the database is enabled. If,
however, you enable the database globally, then the srvctl start database
command starts the database on all nodes on which it is configured to run.
Table A-33
srvctl enable Summary
Command
Description
srvctl enable database
Enables the database resource
srvctl enable diskgroup
Enables a specified disk group on a number of specified nodes
srvctl enable instance
Enables the instance
srvctl enable listener
Enables a listener
srvctl enable nodeapps
Enables node applications and GSD
srvctl enable ons
Enables the Oracle Notification Service daemon
srvctl enable scan
Enables SCAN VIPs
srvctl enable
scan_listener
Enables SCAN listeners
srvctl enable service
Enables a service
srvctl enable vip
Enables a VIP
srvctl enable volume
Enables a volume
srvctl enable database
Enables a cluster database and its instances.
Syntax and Parameters
Use the srvctl enable database command with the following syntax:
srvctl enable database -db db_unique_name [-node node_name]
Table A-34
srvctl enable database Parameters
Parameter
-db database_name
-node node_name
Description
Database name
The name of the node for which the database resource
should be enabled
Note: This parameter can be used only with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl enable database -db mydb1
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srvctl enable diskgroup
Enables a specific disk group on a number of specified nodes.
Syntax and Parameters
Use the srvctl enable diskgroup command with the following syntax:
srvctl enable diskgroup -diskgroup diskgroup_name [-node "node_list"]
Table A-35
srvctl enable diskgroup Parameters
Parameter
Description
-diskgroup diskgroup_name
-nodelist node_list
The Oracle ASM disk group name
Comma-delimited list of node names on which to enable
the disk group
This parameter is only available with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl enable diskgroup -diskgroup diskgroup1 -node "mynode1,mynode2"
srvctl enable instance
Enables an instance for an Oracle RAC database. If you use this command to enable all
instances, then the database is also enabled.
Note:
•
This command is only available with Oracle Clusterware and Oracle
RAC.
•
If you run this command on an Oracle RAC One Node database, then the
command returns an error instructing you to use the database noun,
instead.
Syntax and Parameters
Use the srvctl enable instance command with the following syntax:
srvctl enable instance -db db_unique_name -instance "instance_name_list"
Table A-36
srvctl enable instance Parameters
Parameter
-db db_unique_name
Description
Unique name for the database
Server Control Utility Reference A-57
SRVCTL Command Reference
Table A-36
(Cont.) srvctl enable instance Parameters
Parameter
Description
-instance "instance_name_list"
Comma-delimited list of instance names.
Example
An example of this command is:
$ srvctl enable instance -db crm -instance "crm1,crm2"
srvctl enable listener
Enables a listener resource.
Syntax and Parameters
Use the srvctl enable listener command with the following syntax:
srvctl enable listener [-listener listener_name] [-node node_name]
Table A-37
srvctl enable listener Parameters
Parameter
Description
-listener listener_name
Name of a listener resource. If you do not specify this
parameter, the name of the listener defaults to
LISTENER
-node node_name
Name of a cluster node
Note: This parameter can be used only with Oracle
Clusterware.
Example
To enable the listener named listener_crm on the node named node5, use the
following command:
$ srvctl enable listener -listener listener_crm -node node5
srvctl enable nodeapps
Enables the node applications on all nodes in the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl enable nodeapps command with the following syntax:
srvctl enable nodeapps [-gsdonly] [-adminhelper] [-verbose]
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Table A-38
srvctl enable nodeapps Parameters
Parameter
-gsdonly
-adminhelper
-verbose
Description
Enable only the GSD daemon
Enable the Administrator helper only
Verbose output
Example
An example of this command is:
$ srvctl enable nodeapps -gsdonly -verbose
srvctl enable ons
Enables the Oracle Notification Service daemon.
Note:
This command is only available with Oracle Restart.
Syntax and Parameters
Use the srvctl enable ons command with the following syntax:
srvctl enable ons [-verbose]
The only parameter for this command is -verbose, which indicates that verbose
output should be displayed.
Example
An example of this command is:
$ srvctl enable ons
srvctl enable scan
Enables all SCAN VIPs, by default, or a specific SCAN VIP identified by its
ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl enable scan command with the following syntax:
srvctl enable scan [-scannumber ordinal_number]
Server Control Utility Reference A-59
SRVCTL Command Reference
The only parameter available for this command is -scannumber ordinal_number,
which identifies one of the three SCAN VIPs, and takes a range of values from 1 to 3.
Example
An example of this command is:
$ srvctl enable scan -scannumber 1
srvctl enable scan_listener
Enables all SCAN listeners, by default, or a specific listener identified by its
ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl enable scan_listener command with the following syntax:
srvctl enable scan_listener [-scannumber ordinal_number]
The only parameter available for this command is -scannumber ordinal_number,
which identifies one of three SCAN listeners, and takes a range of values from 1 to 3.
Example
An example of this command is:
$ srvctl enable scan_listener -scannumber 1
srvctl enable service
Enables a service for Oracle Clusterware. Enabling an entire service also affects the
enabling of the service over all of the instances by enabling the service at each one.
When the entire service is already enabled, an srvctl enable service operation
does not affect all of the instances and enable them. Instead, this operation returns an
error. Therefore, you cannot always use the entire set of service operations to
manipulate the service indicators for each instance.
Syntax and Parameters
Use the srvctl enable service command with the following syntax:
srvctl enable service -db db_unique_name -service "service_name_list"
[-instance instance_name | -node node_name]
Table A-39
srvctl enable service Parameters
Parameter
-db db_unique_name
-service "service_name_list"
Description
Unique name for the database
Comma-delimited list of service names
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Table A-39
(Cont.) srvctl enable service Parameters
Parameter
Description
-instance instance_name
Name of the database instance where you want the
service to run
Use this parameter for administrator-managed
databases
Note: This parameter can be used only with Oracle
Clusterware and Oracle RAC.
-node node_name
Name of the node where you want the service to run
Use this parameter for policy-managed databases
Note: This parameter can be used only with Oracle
Clusterware and Oracle RAC.
Examples
The following example globally enables a service:
$ srvctl enable service -db crm -service crm
The following example enables a service to use a preferred instance:
$srvctl enable service -db crm -service crm -instance crm1
srvctl enable vip
Enables a specific VIP.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl enable vip command with the following syntax:
srvctl enable vip -vip vip_name [-verbose]
Table A-40
srvctl enable vip Parameters
Parameter
-vip vip_name
-verbose
Description
The VIP name
Verbose output
Example
The following command enables a VIP named crm1-vip:
$ srvctl enable vip -vip crm1-vip -verbose
Server Control Utility Reference A-61
SRVCTL Command Reference
srvctl enable volume
Enables Oracle Clusterware management for a specific volume or all volumes.
This command allows a volume device to be started by operating on the Oracle
Clusterware resource for the volume. This command does not start the volume device,
and is different from the SQL command ALTER DISKGROUP ENABLE VOLUME or the
ASMCMD command volenable, because these two commands bring the volume
device online, in a running state, making the volume device accessible.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl enable volume command with the following syntax:
srvctl enable volume {-volume volume_name -diskgroup disk_group_name |
-device volume_device}
Table A-41
srvctl enable volume Parameters
Parameter
Description
-volume volume_name
Specify the name of the volume that you want to
enable. This parameter is required.
-diskgroup disk_group_name
Specify the name of the disk group in which the
volume that you want to enable resides.
-device volume_device
Specify the path to the volume device that you want to
enable.
Usage Notes
•
You must specify a particular volume that you want to enable. You can specify a
volume that resides in either a particular disk group or on a particular volume
device.
Example
The following example enables a volume named VOLUME1 that resides in a disk group
named DATA:
$ srvctl enable volume -volume VOLUME1 -diskgroup DATA
getenv
Gets and displays values for the environment variables from the configuration file.
Use SRVCTL with the setenv, getenv, and unsetenv verbs to administer the
environment configurations for databases, instances, services, and node applications.
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Table A-42
srvctl getenv Summary
Command
Description
srvctl getenv database
Gets the database environment values
srvctl getenv listener
Gets the listener environment values
srvctl getenv nodeapps
Gets the node application environment values
srvctl getenv vip
Gets the service environment values
srvctl getenv database
Displays the values for environment variables associated with a database.
Syntax and Parameters
Use the srvctl getenv database command with the following syntax:
srvctl getenv database -db db_unique_name [-envs "name_list"]
Table A-43
srvctl getenv database Parameters
Parameter
Description
-db db_unique_name
-envs "name_list"
Unique name for the database
Comma-delimited list of the names of environment variables
If this parameter is not specified, then the values of all
environment variables associated with the database are
displayed.
Example
The following example gets the environment configuration for the CRM database:
$ srvctl getenv database -db crm
srvctl getenv listener
Gets the environment variables for the specified listener.
Syntax and Parameters
Use the srvctl getenv listener command with the following syntax:
srvctl getenv listener [-listener listener_name] [-envs "name_list"]
Table A-44
srvctl getenv listener Parameters
Parameter
-listener listener_name
Description
Listener name
If this parameter is not specified, the name of the listener
defaults to LISTENER
Server Control Utility Reference A-63
SRVCTL Command Reference
Table A-44
(Cont.) srvctl getenv listener Parameters
Parameter
Description
-envs "name_list"
Comma-delimited list of the names of environment
variables
If this parameter is not specified, then the values of all
environment variables associated with the listener are
displayed.
Example
The following example lists all environment variables specified for the default listener:
$ srvctl getenv listener
srvctl getenv nodeapps
Gets the environment variables for the node application configurations.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl getenv nodeapps command with the following syntax:
srvctl getenv nodeapps [-viponly] [-onsonly] [-envs "name_list"]
Table A-45
srvctl getenv nodeapps Parameters
Parameter
-viponly
-onsonly
-envs "name_list"
Description
Displays the VIP address configuration
Displays the Oracle Notification Service configuration
Comma-delimited list of the names of environment variables
If this parameter is not specified, then SRVCTL displays the
values of all environment variables associated with the node
applications.
Example
The following example lists all environment variables for the node applications:
$ srvctl getenv nodeapps -viponly
srvctl getenv vip
Gets the environment variables for the specified VIP.
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Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl getenv vip command with the following syntax:
srvctl getenv vip -vip vip_name [-envs "name_list"] [-verbose]
Table A-46
srvctl getenv vip Parameters
Parameter
Description
-vip vip_name
-envs "name_list"
The name of the VIP
Comma-delimited list of the names of environment
variables
If this parameter is not specified, then the values of all
environment variables associated with the VIP are
displayed.
Verbose output
-verbose
Example
The following example lists all environment variables for the specified VIP:
$ srvctl getenv vip -vip node1-vip
modify
Enables you to modify the instance configuration without removing and adding
Oracle Clusterware resources.
Using modify preserves the environment in the OCR configuration that would
otherwise need to be reentered. The configuration description is modified in the OCR
configuration, and a new Oracle Clusterware profile is generated and registered. The
change takes effect when the application is next restarted.
Table A-47
srvctl modify Summary
Command
Description
srvctl modify database
Modifies the configuration for a database
srvctl modify instance
Modifies the configuration for an instance
srvctl modify listener
Modifies the listener configuration
srvctl modify network
Modifies the configuration for a network
srvctl modify nodeapps
Modifies the configuration for a node application
srvctl modify ons
Modifies the network configuration for the Oracle Notification
Service daemon
Server Control Utility Reference A-65
SRVCTL Command Reference
Table A-47
(Cont.) srvctl modify Summary
Command
Description
srvctl modify scan
Modifies the SCAN VIP configuration to match that of a specific
SCAN VIP
srvctl modify
scan_listener
Updates the SCAN listener configuration to match that of the
current SCAN VIP configuration
srvctl modify service
Modifies the configuration for a service
srvctl modify srvpool
Modifies a specific server pool
srvctl modify vip
Modifies the VIP to use a different IP address type
srvctl modify database
Modifies the configuration for a database.
Syntax
srvctl modify database -db db_unique_name [-eval] [-dbname db_name]
[-instance instance_name] [-oraclehome oracle_home] [-user user_name]
[-server server_list] [-timeout timeout] [-domain db_domain]
[-spfile spfile] [-pwfile password_file_path]
[-role {PRIMARY|PHYSICAL_STANDBY|LOGICAL_STANDBY|SNAPSHOT_STANDBY}]
[-startoption start_options] [-stopoption stop_options]
[-policy {AUTOMATIC | MANUAL | NORESTART}]
[-serverpool "server_pool_name" [-node node_name]]
[-pqpool pq_server_pool] [{-diskgroup "diskgroup_list" | -nodiskgroup}]
[-acfspath "acfs_path_list"] [-css_critical {yes | no}] [-cpucount cpu_count]
[-memorytarget memory_target] [-maxmemory max_memory]
[-cpucap cpu_cap] [-defaultnetnum network_number] [-force]
Parameters
Table A-48
srvctl modify database Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
Note: You can only use this parameter with a policy-managed
database.
-dbname db_name
The name of the database, if it is different from the unique name
given by the -db parameter.
-instance
instance_name
Instance name prefix; this parameter is required for administratormanaged Oracle RAC One Node databases.
-oraclehome
oracle_home
The path for the Oracle database home directory.
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Table A-48
(Cont.) srvctl modify database Parameters
Parameter
Description
-user user_name
The name of the user that owns the Oracle home directory.
Note: If you specify the -userparameter, then you must run this
command in privileged mode.
-server
server_list
List candidate servers for Oracle RAC One Node databases.
-timeout timeout
Online database relocation timeout, in minutes, for Oracle RAC
One Node databases. The default is 30.
-domain db_domain
The domain for the database.
Note: You can use this parameter only with administratormanaged Oracle RAC One Node databases. If your Oracle RAC
One Node database is policy managed, you cannot use this
parameter.
Note: You must use this parameter if you set the DB_DOMAIN
initialization parameter for the database.
-spfile spfile
The path name of the database server parameter file.
-pwfile
password_file_path
Enter the full path to the location of the password file.
-role {PRIMARY |
PHYSICAL_STANDBY |
LOGICAL_STANDBY |
SNAPSHOT_STANDBY}
The role of the database in an Oracle Data Guard configuration.
The default is PRIMARY.
-startoption
start_options
Startup options for the database, such as OPEN, MOUNT, and
NOMOUNT. The default value is OPEN.
Notes:
•
For multi-word startup options, such as read only and
read write, separate the words with a space and enclose in
double quotation marks (""). For example, "read only".
•
When performing a switch-over in an Oracle Data Guard
configuration, the -startoption for a standby database
that becomes a primary database is always set to OPEN after
the switchover.
-stoption
stop_options
Stop options for the database, such as NORMAL, TRANSACTIONAL,
IMMEDIATE, and ABORT.
Server Control Utility Reference A-67
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Table A-48
(Cont.) srvctl modify database Parameters
Parameter
Description
-policy {AUTOMATIC
| MANUAL |
NORESTART}
Management policy for the database.
•
AUTOMATIC (default): The database is automatically restored
to its previous running condition (started or stopped) upon
restart of the database host computer.
•
MANUAL: The database is never automatically restarted upon
restart of the database host computer. A MANUAL setting does
not prevent Oracle Clusterware from monitoring the
database while it is running and restarting it if a failure
occurs.
•
NORESTART: Similar to the MANUAL setting, the database is
never automatically restarted upon restart of the database
host computer. A NORESTART setting, however, never
restarts the database even if a failure occurs.
-serverpool
"server_pool_name"
[-pqpool
"pq_pool_name"]
Specify the name of a server pool used to control database
placement. If you do not specify this parameter, then it defaults to
the Generic server pool.
You can optionally also specify the name of a parallel query server
pool to be used by the database.
Notes:
•
This parameter can only be used with Oracle Clusterware.
You can use this parameter with the -node parameter but
the server pool must have MAX_SIZE=1 and exactly one
configured server (the one you specify in -node).
•
After you add server pools, you can assign services to them
using the srvctl add service command.
-node node_name
Node name on which you want to register a noncluster, or single
instance, Oracle database.
Note: This parameter can be used only with Oracle Clusterware
and can be used with the -serverpool parameter to create a
policy-managed, noncluster database.
-diskgroup
"disk_group_list"
Comma-delimited list of Oracle ASM disk groups if database uses
Oracle ASM storage.
-acfspath
"acfs_path_list"
A single Oracle ACFS path or a comma-delimited list of Oracle
ACFS paths enclosed in double quotation marks ("") where the
database's dependency is set.
Use this parameter to create dependencies on Oracle ACFS file
systems other than ORACLE_HOME, such as for when the database
uses ORACLE_BASE on a file system that is different from the
ORACLE_HOME file system.
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Table A-48
(Cont.) srvctl modify database Parameters
Parameter
Description
-css_critical {YES
| NO}
You can add weight to a service by setting this parameter to YES.
In the event of a node failure within the cluster, Oracle
Clusterware will evict the node with the least amount of weight,
ensuring that critical services remain available.
Note: You can use this parameter only on an administratormanaged node. Should the node become policy managed, at some
point, this parameter will no longer apply.
-cpucount
cpu_count
Specify the number of CPUs. The default value is 0.
-memorytarget
memory_target
Specify the target memory, in MB, to be allocated for the database.
The default is 0.
-maxmemory
max_memory
Specify the maximum memory, in MB, to be allocated for the
resource. If you specify -memorytarget but not -maxmemory,
then -maxmemory will be the default value of 0. Both maxmemory and -memorytarget are validated as long as memorytarget is less than or equal to -maxmemory.
-cpucap cpu_cap
Specify a percentage from 1 to 100 that is the maximum utilization
of the workload CPUs the database requires. The default is 0.
-defaultnetnum
network_number
Specify a network number to which services will default in the
event you do not specify a network number when you add a
service.
See Also::
•
Oracle Data Guard Concepts and Administration for more information about
database roles
•
SQL*Plus User's Guide and Reference for more information about database
startup options
•
SQL*Plus User's Guide and Reference for more information about database
shutdown options
Usage Notes
•
The srvctl modify database command can convert administrator-managed
databases to policy-managed databases. For a running administrator-managed
database, if the server list is supplied, then the node where the database is
running must be on that list. The instance name prefix cannot be modified after
running the srvctl add database command.
•
You cannot change the management policy from AUTOMATIC (using the -policy
parameter) for Oracle RAC One Node databases. Any attempt to do so results in
an error message. The same is true for the -node parameter, which is used to
change the node on which a noncluster database runs.
Server Control Utility Reference A-69
SRVCTL Command Reference
•
For policy-managed Oracle RAC One Node databases, you can use the serverpool parameter to move an Oracle RAC One Node database between
server pools but you can only specify one server pool. Specifying a list of server
pools returns an error.
Examples
The following example changes the role of a database to a logical standby:
$ srvctl modify database -db crm -role logical_standby
The following example directs the racTest database to use the SYSFILES, LOGS, and
OLTP Oracle ASM disk groups:
$ srvctl modify database -db racTest -diskgroup "SYSFILES,LOGS,OLTP"
srvctl modify instance
For an administrator-managed database, this command modifies the configuration for
a database instance from its current node to another node. For a policy-managed
database, this command defines an instance name to use when the database runs on
the specified node.
Syntax
srvctl modify instance -db db_unique_name -instance instance_name
-node node_name
Parameters
Table A-49
srvctl modify instance Command Parameters
Parameter
Description
-database
db_unique_name
Specify the unique name for the database.
-instance
instance_name
Specify the database instance name.
Notes:
•
•
-node node_name
If you are modifying a policy-managed database instance,
then the instance name must contain an underscore (_), such
as pmdb1_1.
If you specify an instance name that has never been started
before, and is not of the form prefix_number, then you
may have to assign an instance number, undo, and redo in
the SPFILE.
Name of the node on which to run the instance. You can set the
value of this parameter to "" only for a policy-managed database.
Usage Notes
You cannot use this command to rename or relocate a running instance.
A-70 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Examples
The following example to changes the configuration of an administrator-managed
database, amdb, so that the database instance, amdb1, runs on the specified node,
mynode:
$ srvctl modify instance -db amdb -instance amdb1 -node mynode
The following example causes the policy-managed database pmdb, when and if it runs
on mynode, to use the instance name pmdb1:
$ srvctl modify instance -db pmdb -instance pmdb1_1 -node mynode
The following example removes the directive established by the previous example:
$ srvctl modify instance -db pmdb -instance pmdb1_1 -node ""
srvctl modify listener
Changes the Oracle home directory from which the listener runs, the name of the
operating system user who owns Oracle home directory from which the listener runs,
the listener endpoints, or the public subnet on which the listener listens, either for the
default listener, or a specific listener, that is registered with Oracle Restart or with
Oracle Clusterware.
If you want to change the name of a listener, then use the srvctl remove listener and
srvctl add listener commands.
Syntax and Parameters
Use the srvctl modify listener command with the following syntax:
srvctl modify listener [-listener listener_name] [-oraclehome oracle_home]
[-user user_name] [-netnum network_number]
[-endpoints "[TCP:]port_list[/IPC:key][/NMP:pipe_name][/TCPS:s_port][/SDP:port]"]
Table A-50
srvctl modify listener Parameters
Parameter
-listener listener_name
-oraclehome oracle_home
Description
The name of the listener.
If you do not specify this parameter, then SRVCTL uses
the default name LISTENER.
When this parameter is specified, SRVCTL moves the
listener to run from the specified Oracle home.
Note: When using this parameter, the command should
be run as privileged user to enable SRVCTL to update
resource ownership corresponding to the new
ORACLE_HOME owner
-user user_name
The name of the operating system user who will own the
specified Oracle listener
Note: This parameter can be used only with Oracle
Clusterware.
Server Control Utility Reference A-71
SRVCTL Command Reference
Table A-50
(Cont.) srvctl modify listener Parameters
Parameter
Description
-netnum network_number
This parameter changes the public subnet on which the
listener listens.
Note: You should always have at least one listener on the
default network. Do not use this parameter to change the
network of the only listener that listens on the default
network.
-endpoints "[TCP:]port_list [/
IPC:key][/NMP:pipe_name]
[/TCPS:s_port][/SDP:port]"
Protocol specifications for the listener. port_list is
comma-delimited list of port numbers.
Note: You can modify this attribute using Online
Resource Attribute Modification.
Example
The following example changes the TCP ports for the default listener:
$ srvctl modify listener -endpoints "TCP:1521,1522"
srvctl modify network
Modifies the subnet, network type, or IP address type for a network.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl modify network command with one of the following syntax
models:
srvctl modify network [-netnum network_number] [-subnet subnet/netmask
[/if1[|if2|...]]] [-nettype network_type | -iptype {ipv4 | ipv6 | both]}
[-pingtarget "ping_target_list"] [-verbose]
Table A-51
srvctl modify network Parameters
Parameter
-netnum network_number
Description
Specify a network number. The default is 1.
A-72 Oracle Real Application Clusters Administration and Deployment Guide
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Table A-51
(Cont.) srvctl modify network Parameters
Parameter
-subnet subnet/netmask
[/if1[|if2|...]]
Description
Specifies a subnet number for the public network. The
netmask and interfaces specified, if any, change those of the
network you are modifying. If you specify an IPv6 subnet,
then enter a prefix length, such as 64, in place of netmask. If
you do not specify any interface names, then the VIPs use
any interface on the given subnet.
If you are changing the network type using the -nettype
parameter, then you must specify either an existing IPv4 or
IPv6 network using the -subnet parameter. Additionally,
the subnet and netmask you specify in the -subnet
parameter do not change those of the network you are
modifying.
-nettype network_type
-iptype ip_type
-pingtarget
"ping_target_list"
-verbose
Specify the network type: static, dhcp, autoconfig, or
mixed.
The type of IP address: ipv4, ipv6, or both.
Specify a comma-delimited list of IP addresses or host names
to ping.
Verbose output.
Usage Notes
•
On Linux and UNIX systems, you must be logged in as root and on Windows,
you must be logged in as a user with Administrator privileges to run this
command.
•
You can modify the IP address type for a network from IPv4 to IPv6, or from IPv6
to IPv4.
See Also:
Oracle Clusterware Administration and Deployment Guide for more information
•
If you specify static for the network type, then you must provide the virtual IP
address using the srvctl add vip command.
•
If you specify dhcp for the network type, then the VIP agent obtains the IP
address from a DHCP server.
•
If you specify autoconfig for the network type, then the VIP agent generates a
stateless IPv6 address for the network. You can only use this parameter for IPv6
networks. If the subnet/netmask specification is not for an IPv6 address, then
SRVCTL returns an error.
Server Control Utility Reference A-73
SRVCTL Command Reference
•
If you change a network from static to mixed, then you must first configure
GNS, so that the dynamic addresses obtained can have names registered for them.
•
If you specify mixed for the network type, then the VIP resource uses both a static
IP address and an IP address obtained dynamically, either DHCP or autoconfig.
•
If you specify mixed_autoconfig for the network type, then the VIP resource
retains the static IP configuration and either obtains an IP address from a DHCP
server for an IPv4 network specification or generates a stateless auto-configured
IP address for an IPv6 network specification.
Examples
The following example changes the subnet number, netmask, and interface list:
# srvctl modify network -subnet 192.168.2.0/255.255.255.0/eth0
The following example changes the second network to DHCP:
# srvctl modify network -netnum 2 -nettype dhcp
The following example adds an IPv6 subnet and netmask to the default network:
# srvctl modify network -subnet 2606:b400:400:18c0::/64
The following example removes the IPv4 configuration from a network:
# srvctl modify network -iptype ipv6
srvctl modify nodeapps
Modifies the configuration for a node application.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl modify nodeapps command with one of the following syntax
models, specifying either a specific node and VIP or a specific subnet and netmask:
srvctl modify nodeapps {[-node node_name -address {vip_name|vip_address}/
netmask[/if1[|if2|...]] [-skip]] [-nettype network_type] [-emport em_port]
[-onslocalport ons_local_port] [-onsremoteport ons_remote_port]
[-remoteservers host:[port][,host:port,...]] [-verbose]
[-clientdata file] [-pingtarget "ping_target_list"]
srvctl modify nodeapps [-subnet subnet/netmask[/if1[|if2|...]]
[-nettype network_type] [-emport em_port]
[-onslocalport ons_local_port] [-onsremoteport ons_remote_port]
[-remoteservers host:[port][,host:port,...]] [-verbose]
[-clientdata file] [-pingtarget "ping_target_list"]
A-74 Oracle Real Application Clusters Administration and Deployment Guide
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Table A-52
srvctl modify nodeapps Parameters
Parameter
Description
-node node_name
The name of the node on which the node
application you want to modify resides.
-address {vip_name|vip_address}/
netmask[/if1[|if2|...]]
Node-level virtual IP name or address. The
address specified by name or IP must match the
subnet number of the default network.
Note: This parameter must be used for upgrade
configurations and new non-DHCP
configurations
-skip
-subnet subnet/netmask
[/if1[|if2|...]]
Specify this parameter to skip checking the
reachability of the VIP address.
Specifies a subnet number for the public network.
The netmask and interfaces specified, if any,
change those of the default network.
Additionally, if you specify the netmask option,
then you need only specify it for the first node on
each network.
-nettype network_type
Specifies the network server type, such as
static, dhcp, or mixed.
-emport em_port
Local port on which Oracle Enterprise Manager
listens.
Note: You can modify this attribute using Online
Resource Attribute Modification.
-onslocalport ons_local_port
Port on which the Oracle Notification Service
daemon listens for local client connections.
Notes:
•
•
-onsremoteport ons_remote_port
The local port and remote port must each be
unique.
You can modify the local port while the
resource remains online, without restarting
the resource.
Port on which the Oracle Notification Service
daemon listens for connections from remote
hosts.
Notes:
•
•
-remoteservers host:port,
[host:port,...]
The local port and remote port must each be
unique.
You can modify the remote port while the
resource remains online, without restarting
the resource.
List of host:port pairs of remote hosts that are
part of the Oracle Notification Service network
but are not part of the cluster. If you do not
specify a port for a remote host, then the utility
uses the value you specified for
ons_remote_port.
Server Control Utility Reference A-75
SRVCTL Command Reference
Table A-52
(Cont.) srvctl modify nodeapps Parameters
Parameter
Description
-clientdata file
-pingtarget "pingtarget_list"
Specify the file with a wallet to import, or an
empty string to delete a wallet used for SSL to
secure Oracle Notification Service
communication.
Specify a comma-separated list enclosed in
double quotation marks ("") of IPs or host names
to ping.
Verbose output.
-verbose
Example
The following example changes the nodeapps resource on mynode1 to use the
application VIP of 100.200.300.40 with a subnet mask of 255.255.255.0 on the network
interface eth0:
$ srvctl modify nodeapps -node mynode1 -addr 100.200.300.40/255.255.255.0/eth0
srvctl modify ons
Modifies the ports used by the Oracle Notification Service daemon that is registered
with Oracle Restart.
Note:
This command is available only with Oracle Restart.
Syntax and Parameters
Use the srvctl modify ons command with the following syntax:
srvctl modify ons [-onslocalprt ons_local_port] [-onsremoteport ons_remote_port]
[-emport em_port] [-remoteservers host[:port][,host[:port]][...]] [-verbose]
Table A-53
srvctl modify ons Parameters
Parameter
Description
-onslocalport ons_local_port
The Oracle Notification Service daemon listening port for
local client connections
Note: The local port and remote port must each be unique.
-onsremoteport
ons_remote_port
-remoteservers host[:port]
[,host[:port]][...]]
The Oracle Notification Service daemon listening port for
connections from remote hosts
Note: The local port and remote port must each be unique.
A list of host:port pairs of remote hosts that are part of
the Oracle Notification Service network but are not part of
the Oracle Clusterware cluster
Note: If you do not specify port for a remote host, then the
utility uses ons_remote_port.
A-76 Oracle Real Application Clusters Administration and Deployment Guide
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Table A-53
(Cont.) srvctl modify ons Parameters
Parameter
Description
Display verbose output
-verbose
srvctl modify scan
Modifies the number of SCAN VIPs to match the number of IP addresses returned by
looking up the scan_name you specify in DNS.
You use this command when DNS was modified to add, change, or remove IP
addresses, and now you must adjust the Oracle Clusterware resource configuration to
match.
Syntax
srvctl modify scan -scanname scan_name [-netnum network_number]
Parameters
Table A-54
srvctl modify scan Command Parameters
Parameter
Description
-scanname
scan_name
Identifies the SCAN name that resolves to the SCAN VIPs that
you want to modify.
Note: You can modify this attribute using Online Resource
Attribute Modification.
-netnum
network_number
The optional network number from which VIPs are obtained. If
not specified, the VIPs are obtained from the same default
network from which the nodeapps VIP is obtained.
Example
Assume your system currently has a SCAN named scan_name1, and it resolves to a
single IP address in DNS. If you modify the SCAN scan_name1 in DNS to resolve to
three IP addresses, then use the following command to create the additional SCAN
VIP resources:
$ srvctl modify scan -scanname scan_name1
srvctl modify scan_listener
Modifies the SCAN listener to match that of the SCAN VIP, or modifies the SCAN
listener endpoints or service registration restrictions.
Syntax
srvctl modify scan_listener {-update | -endpoints [TCP:]port_list[:FIREWALL={ON|OFF}]
[/IPC:key]
[/NMP:pipe_name][/{TCPS|SDP|EXADIRECT}port_list[:FIREWALL={ON|OFF}]]"} [invitednodes node_list]
[-invitedsubnets subnet_list]
Server Control Utility Reference A-77
SRVCTL Command Reference
Parameters
Table A-55
srvctl modify scan_listener Command Parameters
Parameter
Description
-update
Use this parameter to update SCAN listener configuration to
match the current SCAN VIP configuration. This parameter adds
new resources or removes existing SCAN listener resources to
match the number of SCAN VIP resources.
-endpoints
"[TCP:]port_list[:
FIREWALL={ON|OFF}]
[/IPC:key] [/
NMP:pipe_name][/
{TCPS|SDP|
EXADIRECT}port_lis
t[:FIREWALL={ON|
OFF}]]"]
Protocol specifications for the SCAN listener. Use port_list to
specify a comma-delimited list of TCP ports or listener endpoints.
-invitednodes
node_list
Use this parameter to specify a comma-delimited list of host
names from outside the cluster that are allowed to register with
the SCAN listener.
-invitedsubnets
subnet_list
Use this parameter to specify a comma-delimited list of subnets
from outside the cluster that are allowed to register with the
SCAN listener.
You can also specify endpoints for TCPS, SDP, and EXADIRECT
ports.
Example
Assume your system currently has a SCAN named scan_name1, and you recently
modified the DNS entry to resolve to three IP addresses instead of one. After running
the srvctl modify scan command to create additional SCAN VIP resources, use
the following command to create Oracle Clusterware resources for the additional two
SCAN listeners to go with the two additional SCAN VIPs:
$ srvctl modify scan_listener -update
srvctl modify service
Modifies service configuration.
This command supports some online modifications to the service, such as:
•
Moving a service member from one instance to another
•
Performing online changes to service attributes from DBMS_SERVICE (for
example, failover delay, runtime load balancing goal, and so on)
•
Adding a new preferred or available instance
•
Removing preferred or available instances for a service
A-78 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Caution:
Oracle recommends that you limit configuration changes to the minimum
requirement and that you not perform other service operations while the
online service modification is in progress.
Syntax and Parameters
Use one of the following forms of the srvctl modify service command,
depending on the task you want to perform, with the specified syntax:
To move a service from one instance to another:
srvctl modify service -db db_unique_name -service service_name
-oldinst old_instance_name -newinst new_instance_name [-force]
Note:
This form of the command is only available with Oracle Clusterware.
Table A-56
srvctl modify service Parameters for Moving a Service
Parameter
Description
-db db_unique_name
Specify the unique name for the database.
-service
service_name
Specify a service name. If you do not specify a service name, then
SRVCTL moves all services.
-oldinst
old_instance_name
Specify the name of the instance from which you want to move
the service.
-newinst
new_instance_name
Specify the name of the instance to which you want to move the
service.
-force
Disconnects all sessions during stop or relocate service operations.
To change an available instance to a preferred instance for a service:
srvctl modify service -db db_unique_name -service service_name
-available avail_inst_name -toprefer [-force]
Note:
This form of the command is only available with Oracle Clusterware and does
not accept placement parameters for Oracle RAC One Node databases.
Table A-57
srvctl modify service Parameters for Changing to a Preferred Instance
Parameter
Description
-db db_unique_name
Specify the unique name for the database.
-service
service_name
Specify the name of the service you want to modify.
Server Control Utility Reference A-79
SRVCTL Command Reference
Table A-57
Instance
(Cont.) srvctl modify service Parameters for Changing to a Preferred
Parameter
Description
-available
available_inst_nam
e
Specify the name of the available instance you want to change.
-toprefer
Specify this parameter to change the instance status to preferred.
-force
Disconnect all sessions during stop or relocate service operations.
For planned operations, the user experience is best if using an
Oracle Connection Pool with FAN, and not forcing disconnect.
The FAN planned event causes the Oracle pool to drain the
requests with no interruption to the users.
To change the available and preferred status for multiple instances:
srvctl modify service -db db_unique_name -service service_name
-modifyconfig -preferred "preferred_list" [-available "available_list"]
[-force]
Note:
This form of the command is only available with Oracle Clusterware and does
not accept placement parameters for Oracle RAC One Node databases.
Table A-58
Instances
srvctl modify service Parameters for Changing Status of Multiple
Parameter
Description
-db db_unique_name
Specify the unique name for the database.
-service
service_name
Specify the name of the service you want to modify.
-modifyconfig
This parameter directs SRVCTL to use only the instances named
for this service (unnamed instances already assigned to the service
are removed).
-preferred
"preferred_instanc
e_list"
Specify a comma-delimited list of preferred instances enclosed
within double quotation marks ("").
-available
"available_instanc
e_list"
Specify a comma-delimited list of available instances enclosed
within double quotation marks ("").
-force
Disconnect all sessions during stop or relocate service operations.
For planned operations, the user experience is best if using an
Oracle Connection Pool with FAN, and not forcing disconnect.
The FAN planned event causes the connection pool to drain the
requests with no interruption to the users.
To modify other service attributes or to modify a service for Oracle Clusterware:
A-80 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
srvctl modify service -db db_unique_name -service service_name [-eval]
[-serverpool pool_name] [-cardinality {UNIFORM|SINGLETON}]
[-drain_timeout timeout] [-stopoption {NONE|IMMEDIATE|TRANSACTIONAL}]
[-pqservice pqsvc_name] [-pqpool pq_pool_list]
[-pdb pluggable_database] [-tafpolicy {BASIC|NONE}]
[-edition edition_name] [-role "[PRIMARY][,PHYSICAL_STANDBY]
[,LOGICAL_STANDBY][,SNAPSHOT_STANDBY]"] [-notification {TRUE|FALSE}]
[-dtp {TRUE|FALSE}] [-clbgoal {SHORT|LONG}] [-rlbgoal {NONE|SERVICE_TIME|
THROUGHPUT}]
[-failovertype {NONE|SESSION|SELECT|TRANSACTION}] [-failovermethod {NONE|BASIC}]
[-failoverrestore [NONE|LEVEL1]] [-failoverretry failover_retries]
[-failoverdelay failover_delay] [-policy {AUTOMATIC|MANUAL}]
[-sql_translation_profile profile_name] [-commit_outcome {TRUE|FALSE}]
[-retention retention_time] [-replay_init_time replay_initiation_time]
[-session_state {STATIC|DYNAMIC}] [-global_override] [-verbose] [-force]
Table A-59
srvctl modify service Parameters
Parameter
Description
-db db_unique_name
Specify the unique name for the database.
-service
service_name
Specify the name of the service you want to modify.
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
Note: You can only use this parameter with a policy-managed
service.
-serverpool
pool_name
The name of a server pool used when the database is policy
managed.
Note: This parameter can be used only with Oracle RAC and only
for policy-managed databases.
-cardinality
{UNIFORM|
SINGLETON}
Specify the cardinality of the service, either UNIFORM (offered on
all instances in the server pool) or SINGLETON (runs on only one
instance at a time).
Note: This parameter can be used only with Oracle Clusterware.
-drain_timeout
timeout
Specify the time, in seconds, allowed for resource draining to be
completed. Accepted values are an empty string (""), 0, or any
positive integer. The default value is an empty string, which
means that this parameter is not set. If it is set to 0, then draining
occurs, immediately.
The draining period is intended for planned maintenance
operations. During the draining period, all current client requests
are processed, but new requests are not accepted. When set on the
service this value is used when the command line value is not set.
Server Control Utility Reference A-81
SRVCTL Command Reference
Table A-59
(Cont.) srvctl modify service Parameters
Parameter
Description
-stopoption {NONE|
IMMEDIATE|
TRANSACTIONAL}
Specify the mode in which the service is stopped. If you set this
parameter on the service, then this value is used if you do not set
the value on the command line.
IMMEDIATE permits sessions to drain before the service is
stopped.
TRANSACTIONAL permits sessions to drain for the amount of time
specified in the -drain_timeout parameter. The service is
stopped when the time limit is reached and any remaining
sessions are terminated.
If you specify NONE, then no sessions are terminated.
The default is taken from the service setting, when specified on
the service. Otherwise the default is NONE.
Note: You must use the -stopoption parameter with the force parameter.
-pqservice
pqsvc_name
Specify a comma-delimited list of parallel query service names.
-pqpool
pq_pool_list
Specify a comma-delimited list of parallel query server pool
names.
-pdb
pluggable_database
Specify the name of a pluggable database (PDB).
Note: You can specify a PDB property when you create or modify
a service. The PDB property associates the service with the
specified PDB. You can view the PDB property for a service by
querying the ALL_SERVICES data dictionary view or, when using
the SRVCTL utility, by running the srvctl config service
command.
When create or modify a service with the specified PDB, SRVCTL
does not check if the PDB exists. Before running this command,
you must ensure that the PDB exists.
-tafpolicy {BASIC|
NONE}
Specify the transaction failover (TAF) policy (for administratormanaged databases only).
-edition
edition_name
The initial session edition of the service.
When an edition is specified for a service, all subsequent
connections that specify the service use this edition as the initial
session edition. However, if a session connection specifies a
different edition, then the edition specified in the session
connection is used for the initial session edition.
SRVCTL does not validate the specified edition name. During
connection, the connect user must have USE privilege on the
specified edition. If the edition does not exist or if the connect user
does not have USE privilege on the specified edition, then an error
is raised.
-role "[PRIMARY]
[,PHYSICAL_STANDBY
]
[,LOGICAL_STANDBY]
[,SNAPSHOT_STANDBY
]"
The database modes for which the service should be started
automatically. You can specify one or more roles in a commadelimited list.
Note: The -role parameter is only used at database startup and
by the Oracle Data Guard Broker. All manual service startup must
specify the name of the service to be started by the user.
A-82 Oracle Real Application Clusters Administration and Deployment Guide
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Table A-59
(Cont.) srvctl modify service Parameters
Parameter
Description
-notification
{TRUE|FALSE}
Specify a value of TRUE to enable Fast Application Notification
(FAN) for Oracle Call Interface (OCI) connections.
-dtp {TRUE|FALSE}
Specify TRUE to enable Distributed Transaction Processing for this
service. This ensures that the service is offered at exactly one
instance at a time for XA affinity.
-clbgoal {SHORT|
LONG}
Use this parameter to set a connection load balancing goal: set to
SHORT if using runtime load balancing, set to LONG for long
running connections, such as batch jobs or older SQL*Forms style.
-rlbgoal {NONE|
SERVICE_TIME|
THROUGHPUT}
Use this parameter to set a runtime load balancing goal. Set this
parameter to SERVICE_TIME to balance connections by response
time. Set this parameter to THROUGHPUT to balance connections by
throughput.
-failovertype
{NONE|SESSION|
SELECT|
TRANSACTION}
Use this parameter to set the failover type.
-failovermethod
{NONE|BASIC}
Specify the TAF failover method (for backward compatibility
only).
-failoverrestore
[NONE|LEVEL1]
For Application Continuity, when you set the failoverrestore parameter, session states are restored before
replaying. Use LEVEL1 for ODP.NET and Java with Application
Continuity to restore the initial state.
To enable Application Continuity, set this parameter to
TRANSACTION. To enable TAF, set this parameter to SELECT or
SESSION.
For OCI applications using TAF or Application Continuity, setting
-failoverrestore to LEVEL1 restores the current state. If the
current state differs from the initial state, then a TAF callback is
required. This restriction applies only to OCI.
-failoverretry
failover_retries
For Application Continuity and TAF, specify the number of
attempts to connect after an incident.
-failoverdelay
failover_delay
For Application Continuity and TAF, specify the time delay (in
seconds) between reconnect attempts per incident at failover.
-policy
{AUTOMATIC|MANUAL}
Specify the service management policy.
sql_translation_pr
ofile profile_name
Use this parameter to specify a SQL translation profile for a
service that you are modifying after you have migrated
applications from a non-Oracle database to an Oracle database.
If you want to set the SQL translation profile to a NULL value,
then you must enter an empty string after the -p flag.
Note: Before using the SQL translation feature, you must migrate
all server-side application objects and data to the Oracle database.
-commit_outcome
{TRUE|FALSE}
Enable Transaction Guard; when set to TRUE, the commit outcome
for a transaction is accessible after the transaction's session fails
due to a recoverable outage.
Server Control Utility Reference A-83
SRVCTL Command Reference
Table A-59
(Cont.) srvctl modify service Parameters
Parameter
Description
-retention
retention_time
For Transaction Guard (with the -commit_outcome parameter
set to TRUE); this parameter determines the amount of time (in
seconds) that the commit outcome is retained in the database.
-replay_init_time
replay_initiation_
time
For Application Continuity; this parameter specifies the time, in
seconds, from when the original request started. Application
Continuity will not replay after the specified amount of time has
passed. This attribute avoids the unintentional replay of a request
when a system is recovered after a long period. The default value
is 300 (5 minutes).
-session_state
{STATIC|DYNAMIC}
For Application Continuity; this parameter specifies whether the
session state that is not transactional is changed by the
application. Oracle recommends a value of DYNAMIC for most
applications. If you are unsure which value to use or you can
customize the application, then use DYNAMIC. STATIC mode is on
request for database-agnostic applications, that never change nontransactional state inside a request.
-global_override
Override value to modify the global service attributes.
Use this parameter with the -role, -policy, -notification,
-failovertype, -failovermethod, -failoverdelay, failoverretry and -edition parameters.
–verbose
Display verbose output.
-force
Force the modify operation, stopping the service on some nodes as
necessary.
Usage Notes
•
When performing online changes to service attributes (for example, failover delay,
Runtime Load Balancing Goal, and so on), the changes take effect only when the
service is next (re)started.
•
When a service configuration is modified so that a new preferred or available
instance is added, the running state of the existing service is not affected.
However, the newly added instances will not automatically provide the service,
until a srvctl start service command is issued.
•
When there are available instances for the service, and the service configuration is
modified so that a preferred or available instance is removed, the running state of
the service may change unpredictably:
–
The service is stopped and then removed on some instances according to the
new service configuration.
–
The service may be running on some instances that are being removed from
the service configuration.
–
These services will be relocated to the next free instance in the new service
configuration.
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Because of these considerations, when the online service is being modified, users may
experience a brief service outage on some instances even if the instances are not being
removed. Or users may experience a brief service outage on instances that are being
removed from the service.
Examples
An example of moving a service member from one instance to another is:
$ srvctl modify service -db crm -service crm -oldinst crm1 -newinst crm2
An example of changing an available instance to a preferred instance is:
$ srvctl modify service -db crm -service crm -available crm1 -toprefer
The following command exchanges a preferred and available instance:
$ srvctl modify service -db crm -service crm -modifyconfig -preferred "crm1" \
-available "crm2"
Related Topics:
Oracle Data Guard Broker
Oracle Database SQL Translation and Migration Guide
srvctl modify srvpool
Modifies a server pool in a cluster. If minimum size, maximum size, and importance
are numerically increased, then the CRS daemon may attempt to reassign servers to
this server pool, if by resizing other server pools have comparatively lower minimum
size and importance, to satisfy new sizes of this server pool.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl modify srvpool command with the following syntax:
srvctl modify srvpool -serverpool pool_name [-eval] [-importance importance]
[-min min_size] [-max max_size] [-servers "server_list"]
[-category "server_category"] [-verbose] [-force]
Table A-60
srvctl modify srvpool Parameters
Parameter
-serverpool pool_name
-eval
-importance importance
Description
The name of the server pool to modify,
Use this parameter to hypothetically evaluate the
impact of the command on the system.
The new importance of the server pool.
Server Control Utility Reference A-85
SRVCTL Command Reference
Table A-60
(Cont.) srvctl modify srvpool Parameters
Parameter
Description
-min min_size
The new minimum size of the server pool. The
default value is 0.
-max max_size
The new maximum size of the server pool. A value
of -1 sets the server pool maximum size to
UNLIMITED.
-servers "server_list"
-category "server_category"
A comma-delimited list of candidate server names.
Note: In Oracle Database 12c, servers are assigned to
server pools according to the value of the category parameter.
Server category (or "" for empty category value).
Display verbose output
-verbose
Force the operation even though the utility stops
some resource(s).
-force
Example
The following example changes the importance rank to 0, the minimum size to 2, and
the maximum size to 4 for the server pool srvpool1:
$ srvctl modify srvpool -serverpool srvpool1 -importance 0 -min 2 -max 4
srvctl modify vip
Modifies IP address type but you can also use it to modify just the IP address.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl modify vip command with the following syntax:
srvctl modify vip -node node_name -address {VIP_name|ip}/netmask[/if1[|if2|...]]
[-netnum network_number] [-verbose]
Table A-61
srvctl modify vip Parameters
Parameter
-node node_name
Description
The name of the node on which you are changing the VIP.
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Table A-61
(Cont.) srvctl modify vip Parameters
Parameter
Description
-address {VIP_name|ip}/
netmask
[/if1[|if2|...]]
Use this parameter to change the configuration of an existing
VIP. If the VIP has an IPv4 address and the address you
specify is IPv6, and the IP address type is set to both and the
network type is set to static, then SRVCTL adds the IPv6
address to the existing IPv4 address of that resource.
You can specify one VIP_name or IP address, along with an
IPv4 netmask or IPv6 prefix length.
-netnum network_number
The optional network number from which VIPs are obtained.
If you do not specify this parameter, then the VIPs are
obtained from the same default network from which the
nodeapps VIP is obtained.
Verbose output
-verbose
Note:
You cannot have multiple VIPs on the same net number (subnet or interface
pair) on the same node.
Example
The following example adds an IPv4 address to a VIP, if one does not already exist. If
the VIP has an IPv4 address, then it is replaced with the new network specification.
# srvctl modify vip -node node7 -address 192.168.16.17/255.255.255.0 -netnum 2
predict
The predict command predicts what happens when a resource fails and cannot be
restarted on the same node. This command does not make any modifications to the
system.
Table A-62
srvctl predict Summary
Command
Description
srvctl predict database
Predicts the consequences of database failure
srvctl predict diskgroup
Predicts the consequences of diskgroup failure
srvctl predict listener
Predicts the consequences of listener failure
srvctl predict network
Predicts the consequences of network failure
srvctl predict scan
Predicts the consequences of SCAN failure
srvctl predict
scan_listener
Predicts the consequences of SCAN listener failure
srvctl predict service
Predicts the consequences of service failure
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Table A-62
(Cont.) srvctl predict Summary
Command
Description
srvctl predict vip
Predicts the consequences of VIP failure
srvctl predict database
The srvctl predict database command predicts what happens if the specified
database fails.
Syntax and Parameters
Use the srvctl predict database command with the following syntax:
srvctl predict database -db db_unique_name [-verbose]
Table A-63
srvctl predict database Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
Verbose output.
-verbose
Example
The following example predicts what happens if the database named racdb fails:
srvctl predict database -db racdb
srvctl predict diskgroup
Predicts the consequences of and Oracle ASM disk group failure.
Syntax and Parameters
Use the srvctl predict diskgroup command with the following syntax:
srvctl predict diskgroup -diskgroup diskgroup_name [-verbose]
Table A-64
srvctl predict diskgroup Parameters
Parameter
Description
-diskgroup diskgroup_name
The name of the Oracle ASM disk group for which you
want to evaluate failure
-verbose
Display verbose output.
Example
An example of this command is:
$ srvctl predict diskgroup -diskgroup data
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srvctl predict listener
Predicts the consequences of listener failure.
Syntax and Parameters
Use the srvctl predict listener command with the following syntax:
srvctl predict listener listener_name [-verbose]
Table A-65
srvctl predict listener Parameters
Parameter
Description
-listener listener_name
Specify the name of the listener for which you want to
predict the consequences of a failure.
Display verbose output.
-verbose
Example
An example of this command is:
$ srvctl predict listener -listener NODE3_CRMAPP_LISTENER
srvctl predict network
Predicts the consequences of network failure.
Syntax and Parameters
Use the srvctl predict network command with the following syntax:
srvctl predict network [-netnum network_number [-verbose]
Table A-66
srvctl predict network Parameters
Parameter
Description
-netnum network_number
Specify the network for which you want to evaluate
failure. The default value is 1.
-verbose
Display verbose output.
Example
An example of this command is:
$ srvctl predict network -netnum 2
srvctl predict scan
Predicts the consequences of SCAN failure.
Syntax and Parameters
Use the srvctl predict scan command with the following syntax:
srvctl predict scan -scannumber ordinal_number [-verbose]
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SRVCTL Command Reference
Table A-67
srvctl predict scan Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies the SCAN VIP
for which you want to simulate failure. The range
of values you can specify for this parameter is 1 to
3.
Display verbose output.
-verbose
Example
An example of this command is:
$ srvctl predict scan -scannumber 1 -verbose
srvctl predict scan_listener
Predicts the consequences of SCAN listener failure.
Syntax and Parameters
Use the srvctl predict scan_listener command with the following syntax:
srvctl predict scan_listener -scannumber ordinal_number [-verbose]
Table A-68
srvctl predict scan_listener Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies the SCAN
listener. The range of values you can specify
for this parameter is 1 to 3.
-verbose
Display verbose output.
Example
An example of this command is:
$ srvctl predict scan_listener -scannumber 1
srvctl predict service
Predicts the consequences of service failure.
Syntax and Parameters
Use the srvctl predict service command with the following syntax:
srvctl predict service -db db_unique_name -service service_name [-verbose]
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Table A-69
srvctl predict service Parameters
Parameter
Description
-db db_unique_name
-service "service_name,..."
Unique name for the database
Comma-delimited list of service names
Display verbose output
-verbose
Example
To evaluate the consequences of failure of the service named crm for the database
racdb:
$ srvctl predict service -db racdb -service "crm"
srvctl predict vip
Predicts the consequences of VIP failure.
Syntax and Options
Use the srvctl predict vip command with the following syntax:
srvctl predict vip [-vip vip_name] [-verbose]
Table A-70
srvctl predict vip Parameters
Parameter
Description
-vip vip_name
Specify the name of the VIP for which you
want to evaluate the consequences of failure.
-verbose
Display verbose output
Example
An example of this command is:
$ srvctl predict vip -vip racdb1_vip
relocate
The relocate command causes the specified object to run on a different node.
The specified object must be running already.
The relocation of the object is temporary until you modify the configuration. The
previously described modify command permanently changes the configuration.
Server Control Utility Reference A-91
SRVCTL Command Reference
Table A-71
srvctl relocate Command Summary
Command
Description
srvctl relocate
database
Relocates an Oracle RAC One Node database to a different node.
srvctl relocate
instance
Relocates a database instance.
srvctl relocate
scan
Relocates a SCAN VIP from its current hosting server to another
server within the cluster.
srvctl relocate
scan_listener
Relocates a SCAN listener from its current hosting server to
another server within the cluster.
srvctl relocate
service
Relocates the named services from one named instance to another
named instance, or all services that can move, if no service is
specified. Services that cannot move remain where they are.
srvctl relocate
vip
Relocates a specific VIP from one node to another node within the
cluster.
srvctl relocate database
The srvctl relocate database command initiates the relocation of an Oracle
RAC One Node database from one node to another node. This command also cleans
up after a failed relocation.
The srvctl relocate database command can only be used for relocating Oracle
RAC One Node databases.
Syntax and Parameters
Use the srvctl relocate database command with one of these syntax models:
srvctl relocate database -db db_unique_name [-node target_node]
[-timeout timeout] [-stopoption NORMAL] [-verbose]
srvctl relocate database -db db_unique_name -abort [-revert] [-verbose]
Table A-72
srvctl relocate database Parameters
Parameter
-db db_unique_name
-node target
Description
Unique name of the database to relocate.
Target node to which to relocate the Oracle RAC One Node
database.
Note: You must supply this parameter if you are relocating
an administrator-managed Oracle RAC One Node database.
-timeout timeout
-stopoption NORMAL
Online database relocation timeout, in minutes, for Oracle
RAC One Node databases. The default is 30.
Use this parameter to shut down an existing database
instance using SHUTDOWN NORMAL instead of the default of
SHUTDOWN TRANSACTIONAL LOCAL for a primary
database or SHUTDOWN IMMEDIATE for a standby database.
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Table A-72
(Cont.) srvctl relocate database Parameters
Parameter
Description
Abort failed online database relocation.
-abort
-revert
-verbose
Removes the target node of a failed online relocation
request from the candidate server list of an administratormanaged Oracle RAC One Node database.
Verbose output.
Usage Notes
•
If the Oracle RAC One Node database you want to relocate is not running, then
the command returns an error.
•
If another online database relocation is active for this Oracle RAC One Node
database, then the command returns an error.
•
If an online database relocation for this Oracle RAC One Node database has failed
and the target nodes are not the same for either relocation, then the command
returns an error instructing you to abort the failed online database relocation and
then initiate a new one.
•
If an online database relocation for this Oracle RAC One Node database has failed
and the target nodes are the same (or you do not specify the target), then the
command attempts to relocate the database.
Example
The following example relocates an administrator-managed Oracle RAC One Node
database named rac1 to a server called node7.
srvctl relocate database -db rac1 -node node7
srvctl relocate scan
Relocates a specific SCAN VIP from its current hosting node to another node within
the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl relocate scan command with the following syntax:
srvctl relocate scan -scannumber ordinal_number [-node node_name]
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SRVCTL Command Reference
Table A-73
srvctl relocate scan Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN
VIP you want to relocate. The range of values you
can specify for this parameter is 1 to 3.
-node node_name
The name of a single node.
If you do not specify this parameter, then the
utility chooses the node to which the SCAN VIP is
relocated.
Example
An example of this command is:
$ srvctl relocate scan -scannumber 1 -node node1
srvctl relocate scan_listener
Relocates a specific SCAN listener from its current hosting node to another node
within the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl relocate scan_listener command with the following syntax:
srvctl relocate scan_listener -scannumber ordinal_number [-node node_name]
Table A-74
srvctl relocate scan_listener Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN VIP
you want to relocate. The range of values you can
specify for this parameter is 1 to 3.
-node node_name
The name of a single node.
If you do not specify this parameter, then the utility
chooses the node to which the SCAN VIP is relocated.
Example
An example of this command is:
$ srvctl relocate scan_listener -scannumber 3
srvctl relocate server
Relocates servers to a server pool in the cluster.
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Syntax and Parameters
Use the srvctl relocate server command with the following syntax:
srvctl relocate server -servers "server_name_list" -serverpool pool_name
[-eval] [-force]
Table A-75
srvctl relocate server Parameters
Parameter
Description
-servers "server_name_list"
A single server name or a comma-delimited list of server
names enclosed in double quotation marks ("") that you
want to relocate to a different server pool.
-serverpool pool_name
The name of the server pool to which you want to move
servers.
-eval
Use this parameter to hypothetically evaluate the impact
of the command on the system.
-force
Use the -force parameter to force the relocation of
servers even if it means stopping some resources.
Example
An example of this command is:
$ srvctl relocate server -servers "server1, server2" -serverpool sp3
srvctl relocate service
Use the srvctl relocate service command to temporarily relocate the specified
service names from one specified instance to another specified instance.
This command works on only one source instance and one target instance at a time,
relocating a service or all services from a single source instance to a single target
instance.
Syntax
srvctl relocate service -db db_unique_name [-service service_name
| -pdb pluggable_database] {-oldinst old_inst_name
[-newinst new_inst_name] | -currentnode source_node [-targetnode target_node]} [drain_timeout timeout]
[-wait YES | NO] [-pq] [-force [-noreplay]] [-eval] [-verbose]
Parameters
Table A-76
srvctl relocate service Command Parameters
Parameter
Description
-db db_unique_name
Specify a unique name for the database.
-service
service_name
Specify the name of the service you want to relocate. If you do not
specify any services, then all services that can be relocated, are
relocated. Those that cannot be relocated remain in place.
Server Control Utility Reference A-95
SRVCTL Command Reference
Table A-76
(Cont.) srvctl relocate service Command Parameters
Parameter
Description
-pdb
pluggable_database
Use this parameter to relocate services running on a specific
pluggable database.
-oldinst
old_inst_name
Specify the name of the instance from which you are relocating the
service.
-newinst
new_inst_name
Specify the name of the instance to which you are relocating the
service. This parameter is optional. If you do not specify an
instance, then Oracle Clusterware chooses a new one.
Note: If you are using an administrator-managed database, then
you must use the -oldinst and -newinst parameters and the
target instance must be on the preferred or available list for the
service.
-currentnode
source_node
Name of the node where the service is currently running.
-targetnode
target_node
Name of node where the service is to be relocated. If you do not
specify a target node, then Oracle Clusterware chooses a new
location.
Note: If you are using a policy-managed database, then you must
use the -currentnode and -targetnode parameters.
-drain_timeout
timeout
Specify the time, in seconds, allowed for resource draining to be
completed. Accepted values are an empty string (""), 0, or any
positive integer. The default value is an empty string, which
means that this parameter is not set. If it is set to 0, then draining
occurs, immediately.
The draining period is intended for planned maintenance
operations. During the draining period, all current client requests
are processed, but new requests are not accepted. When set on the
service this value is used when the command line value is not set.
-wait YES | NO
Choose YES to wait until service draining is completed on the
node from which you are relocating the service.
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Table A-76
(Cont.) srvctl relocate service Command Parameters
Parameter
Description
-stopoption option
Specify the mode in which the service is stopped. When set on the
service, this value is used if you do not set the value on the
command line.
IMMEDIATE permits sessions to drain before the service is
stopped.
TRANSACTIONAL permits sessions to drain for the amount of time
specified in the -drain_timeout parameter. The service is
stopped when the time limit is reached and any remaining
sessions are terminated.
If you specify NONE, then no sessions are terminated.
The default is taken from the service setting, when specified on
the service. Otherwise the default is NONE.
Note: You must use the -stopoption parameter with the force parameter.
–pq
Performs the action on a parallel query service.
–force [-noreplay]
Disconnect all sessions during stop or relocate service operations.
Optionally, you can specify the -noreplay parameter if you do
not want Application Continuity to replay in-flight transactions
after a session is terminated during stop or relocate service
operations.
The -noreplay parameter is not limited to use with -force but
-force does require -noreplay if you do not want to replay inflight transactions after you force the service to disconnect all
sessions.
–eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
–verbose
Verbose output.
Example
To temporarily relocate a named service member for the crm service from the
database instance crm1 to the database instance crm3:
$ srvctl relocate service -db crm -service crm -oldinst crm1 -newinst crm3
Related Topics:
SQL*Plus User's Guide and Reference
srvctl relocate vip
Relocates a specific VIP from its current hosting node to another node within the
cluster.
Syntax and Options
Use the srvctl relocate vip command with the following syntax:
Server Control Utility Reference A-97
SRVCTL Command Reference
srvctl relocate vip -vip vip_name [-node node_name] [-force] [-verbose]
Table A-77
srvctl relocate vip Parameters
Parameter
Description
-vip vip_name
-node node_name
Specify the name of the VIP you want to relocate.
Specify the name of the target node where the VIP should be
relocated.
Specify this option to force the relocation of the VIP.
-force
Display verbose output.
-verbose
Example
An example of this command is:
$ srvctl relocate vip -vip vip1 -node node3
remove
Removes the configuration information for the specified target from Oracle
Clusterware. Environment settings for the object are also removed.
Using this command does not destroy the specified target.
Use the remove verb to remove the associated resource from the management of
Oracle Clusterware or Oracle Restart. Depending on the noun used, you can remove
databases, services, nodeapps, Oracle Notification Service, and listeners.
If you do not use the force parameter (-force), then Oracle Clusterware or Oracle
Restart prompts you to confirm whether to proceed. If you use -force, then the
remove operation proceeds without prompting and continues processing even when it
encounters errors. Even when the Oracle Clusterware resources cannot be removed,
the OCR configuration is removed, so that the object now appears not to exist, but
there are still Oracle Clusterware resources. Use the force parameter (-force) with
extreme caution because this could result in an inconsistent OCR.
To use the remove verb, you must first stop the node applications, database, instance,
or service for which you are specifying srvctl remove. Oracle recommends that
you perform a disable operation before using this command, but this is not required.
You must stop the target object before running the srvctl remove command. See
the stop command.
Table A-78
srvctl remove Summary
Command
Description
srvctl remove database
Removes a database and configuration
srvctl remove diskgroup
Removes a disk group from the Oracle Clusterware or Oracle
Restart configuration
srvctl remove instance
Removes instances and configurations of administrator-managed
databases
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Table A-78
(Cont.) srvctl remove Summary
Command
Description
srvctl remove listener
Removes the configuration of the specified listener from Oracle
Clusterware or Oracle Restart
srvctl remove network
Removes a network from the cluster configuration
srvctl remove nodeapps
Removes node applications
srvctl remove ons
Removes Oracle Notification Service instances
srvctl remove scan
Removes all Oracle Clusterware resources for all SCAN VIPs
srvctl remove
scan_listener
Removes all Oracle Clusterware resources for all SCAN listeners
srvctl remove service
Removes services from the Oracle Clusterware or Oracle Restart
configuration
srvctl remove srvpool
Removes a specific server pool
srvctl remove vip
Removes specific VIPs
srvctl remove volume
Removes a specific volume
srvctl remove database
Removes database configurations.
After running this command, ensure that the password file is in the default location if
you want to connect to the database as the SYS user with the SYS user's password.
Syntax
srvctl remove database -db db_unique_name [-force] [-noprompt] [-verbose]
Parameters
Table A-79
srvctl remove database Command Parameters
Parameter
Description
-database
db_unique_name
Unique name for the database.
-force
Forcibly remove the database and ignore any dependencies.
-noprompt
Suppress prompts.
-verbose
Display verbose output.
Example
To remove a database named crm:
$ srvctl remove database -db crm
Server Control Utility Reference A-99
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srvctl remove diskgroup
Removes a specific Oracle ASM disk group resource from Oracle Clusterware or
Oracle Restart.
Syntax and Parameters
Use the srvctl remove diskgroup command with the following syntax:
srvctl remove diskgroup -diskgroup diskgroup_name [-force]
Table A-80
srvctl remove diskgroup Parameters
Parameter
Description
-diskgroup diskgroup_name
The Oracle ASM disk group name.
Force remove (ignore dependencies)
-force
Example
An example of this command is:
$ srvctl remove diskgroup -diskgroup DG1 -force
srvctl remove instance
Removes the configurations for an instance of an administrator-managed database. To
remove the configurations of a policy-managed database, you must shrink the size of
the server pool with the srvctl modify srvpool command.
If you use the -force parameter, then any services running on the instance stop.
Oracle recommends that you reconfigure services to not use the instance to be
removed as a preferred or available instance before removing the instance.
Note:
•
This command is only available with Oracle Clusterware and Oracle
RAC.
•
If you attempt to use this command on an Oracle RAC One Node
database, then the command returns an error stating that cannot remove
the instance except by removing the database.
Syntax and Parameters
Use the srvctl remove instance command with the following syntax:
srvctl remove instance -db db_unique_name -instance instance_name
[-noprompt] [-force]
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Table A-81
srvctl remove instance Parameters
Parameter
Description
-db db_unique_name
-instance instance_name
Unique name for the administrator-managed database.
Instance name.
Suppress prompts
-noprompt
Specify this parameter to skip checking that the instance is not
running, and remove it even though it is running. This
parameter also skips checking that the instance has no running
services using it, and causes those services to stop before the
instance is removed.
-force
Example
An example of this command is:
$ srvctl remove instance -db crm -instance crm01
srvctl remove listener
Removes the configuration of a specific listener or all listeners from Oracle
Clusterware or Oracle Restart.
Syntax and Parameters
Use the srvctl remove listener command with the following syntax:
srvctl remove listener [-listener listener_name | -all] [-force]
Table A-82
srvctl remove listener Parameters
Parameter
-listener listener_name
-all
-force
Description
Name of the listener that you want to remove.
If you do not specify a listener name, then the listener name
defaults to LISTENER for a database listener;
LISTENER_ASM for an Oracle ASM listener; or
LISTENER_LEAF for a Leaf Node listener.
Removes all listener configurations.
Specify this parameter to skip checking whether there are
other resources that depend on this listener, such as
databases, and remove the listener anyway.
Examples
The following command removes the configuration for the listener named lsnr01:
$ srvctl remove listener -listener lsnr01
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SRVCTL Command Reference
srvctl remove network
Removes the network configuration. You must have full administrative privileges to
run this command. On Linux and UNIX systems, you must be logged in as root and
on Windows systems, you must be logged in as a user with Administrator privileges.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl remove network command as follows:
srvctl remove network {-netnum network_number | -all} [-force] [-verbose]
Table A-83
srvctl remove network Parameters
Parameter
-netnum network_number
Description
Specifies which network to remove
Remove all networks
-all
Force remove the networks
-force
-verbose
Verbose output
Example
An example of this command is:
# srvctl remove network -netnum 3
srvctl remove nodeapps
Removes the node application configuration.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl remove nodeapps command as follows:
srvctl remove nodeapps [-force] [-noprompt] [-verbose]
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Table A-84
srvctl remove nodeapps Parameters
Parameter
Description
Force remove
-force
Suppress prompts
-noprompt
Verbose output
-verbose
Usage Notes
You must have full administrative privileges to run this command. On Linux and
UNIX systems, you must be logged in as root and on Windows systems, you must be
logged in as a user with Administrator privileges.
Example
An example of this command is:
# srvctl remove nodeapps
srvctl remove ons
Removes Oracle Notification Service from the Oracle Grid Infrastructure home.
Note:
This command is only available with Oracle Restart.
Syntax and Parameters
Use the srvctl remove ons command with the following syntax:
srvctl remove ons [-force] [-verbose]
Table A-85
srvctl remove ons Parameters
Parameter
-force
-verbose
Description
Force remove
Verbose output
srvctl remove scan
Removes Oracle Clusterware resources from all SCAN VIPs.
Syntax
srvctl remove scan [-netnum network_number] [-force] [-noprompt]
Server Control Utility Reference A-103
SRVCTL Command Reference
Parameters
Table A-86
srvctl remove scan Command Parameters
Parameter
Description
-netnum
network_number
The optional network number from which VIPs are obtained. If
not specified, the VIPs are obtained from the same default
network from which the nodeapps VIP is obtained.
–force
Removes the SCAN VIPs even though there are SCAN listeners
running that are dependent on the SCAN VIPs.
–noprompt
Use this parameter to suppress all prompts.
Usage Notes
If you use the -force option, then SCAN VIPs that are running are not stopped
before the dependent resources are removed, which may require manual cleanup.
Examples
An example of this command is:
$ srvctl remove scan -force
srvctl remove scan_listener
Removes Oracle Clusterware resources from all SCAN listeners.
Syntax
srvctl remove scan_listener [-netnum network_number] [-force] [-noprompt]
Parameters
Table A-87
srvctl remove scan_listener Command Parameters
Parameter
Description
-netnum
network_number
The optional network number from which SCAN VIPs are
obtained. If you do not specify this parameter, then the SCAN
VIPs are obtained from the same default network from which the
nodeapps VIP is obtained.
-force
Removes the SCAN listener without stopping the SCAN listener if
it is running.
–noprompt
Use this parameter to suppress all prompts.
Examples
An example of this command is:
$ srvctl remove scan_listener -force
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srvctl remove service
Removes the configuration for a service.
Syntax and Parameters
Use the srvctl remove service command as follows:
srvctl remove service -db db_unique_name -service service_name
[-instance instance_name] [-global_override]
Table A-88
srvctl remove service Parameters
Parameter
-db db_unique_name
-service service_name
-instance instance_name
-global_override
Description
Unique name for the database
Service name
Instance name of an administrator-managed database.
Note: This parameter can be used only for Oracle
Clusterware.
Override value to operate on a global service. This parameter
is ignored for a non-global service.
Examples
This command removes the sales service from all instances of the clustered database
named crm:
$ srvctl remove service -db crm -service sales
The following example removes the sales service from a specific instance of the crm
clustered database:
$ srvctl remove service -db crm -service sales -instance crm02
srvctl remove srvpool
Removes a specific server pool. If there are databases or services that depend upon
this server pool, then those resources are removed from the server pool first so that the
remove server pool operation succeeds.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl remove srvpool command with the following syntax:
srvctl remove srvpool -serverpool pool_name [-eval] [-verbose]
Server Control Utility Reference A-105
SRVCTL Command Reference
Table A-89
srvctl remove srvpool Parameters
Parameter
Description
-eval
Evaluates the effects of removing a server pool without making any
changes to the system.
Display verbose output.
-verbose
Usage Notes
If you successfully remove the specified server pool, then the CRS daemon may assign
its servers to other server pools depending upon their minimum size, maximum size,
and importance. The CRS daemon may also return these servers to its Free server pool.
Example
An example of this command is:
$ srvctl remove srvpool -serverpool srvpool1
srvctl remove vip
Removes specific VIPs.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl remove vip command with the following syntax:
srvctl remove vip -vip "vip_name_list" [-force] [-noprompt] [-verbose]
Table A-90
srvctl remove vip Parameters
Parameter
Description
-vip "vip_name_list"
A comma-delimited list of VIP names surrounded by double
quotation marks ("")
-force
-noprompt
-verbose
Force remove
Suppress prompts
Verbose output
Example
An example of this command is:
$ srvctl remove vip -vip "vip1,vip2,vip3" -force -noprompt -verbose
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SRVCTL Command Reference
srvctl remove volume
Removes a specific volume.
Note:
•
This command is only available with Oracle Clusterware.
•
The volume gets created when you create volumes in Oracle ASM.
See Also:
Oracle Automatic Storage Management Administrator's Guide for more
information about creating volumes
Syntax and Parameters
Use the srvctl remove volume command with one of these syntax models:
srvctl remove volume -volume volume_name -diskgroup disk_group_name [-force]
srvctl remove volume -device volume_device [-force]
Table A-91
srvctl remove volume Parameters
Parameter
Description
-volume volume_name
Specify the name of the volume that you want to remove.
This parameter is required.
-diskgroup disk_group_name
Specify the name of the disk group in which the volume
that you want to remove resides.
-device volume_device
Specify the path to the file system resource in which the
volume that you want to remove resides.
-force
Removes the volume even if it is running.
Usage Notes
You must specify a particular volume that you want to remove. You can specify a
volume that resides in either a particular disk group or on a particular volume device.
Example
The following example removes a volume named VOLUME1 that resides in a disk
group named DATA:
$ srvctl remove volume -volume VOLUME1 -diskgroup DATA
setenv
The setenv command sets values for the environment in the configuration file.
Server Control Utility Reference A-107
SRVCTL Command Reference
Use setenv to set environment variables—items such as language or TNS_ADMIN—
for Oracle Clusterware that you would typically set in your profile or session when
you manage this database or database instance.
The unsetenv command unsets values for the environment in the configuration file.
Table A-92
srvctl setenv Summary
Command
Description
srvctl setenv database
Administers cluster database environment configurations
srvctl setenv listener
Administers listener environment configurations
Note: You cannot use this command to administer SCAN
listeners.
srvctl setenv nodeapps
Administers node application environment configurations
srvctl setenv vip
Administers VIP environment configurations
srvctl setenv database
Administers cluster database environment configurations.
Syntax and Parameters
Use the srvctl setenv database command with one of these syntax models:
srvctl setenv database -db db_unique_name -envs "name=val[,name=val][...]"
srvctl setenv database -db db_unique_name -env "name=val"
Table A-93
srvctl setenv database Parameters
Parameter
-db db_unique_name
Description
Unique name for the database
-envs "name=val,..."
Comma-delimited list of name-value pairs of environment
variables
-env "name=val"
Enables single environment variable to be set to a value
that contains commas or other special characters
Example
The following example sets the language environment configuration for a cluster
database:
$ srvctl setenv database -db crm -env LANG=en
srvctl setenv listener
Administers listener environment configurations.
Syntax and Parameters
Use the srvctl setenv listener with one of these syntax models:
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SRVCTL Command Reference
srvctl setenv listener [-listener listener_name] -envs "name=val[,name=val][...]"
srvctl setenv listener [-listener listener_name] -env "name=val"
Table A-94
srvctl setenv listener Parameters
Parameter
Description
-listener listener_name
Name of the listener.
If you do not specify this parameter, then the listener name
defaults to LISTENER.
-envs "name=val"
Comma-delimited list of name-value pairs of environment
variables.
-env "name=val"
Enables single environment variable to be set to a value that
contains commas or other special characters.
Example
The following example sets the language environment configuration for the default
listener:
$ srvctl setenv listener -env "LANG=en"
srvctl setenv nodeapps
Sets the environment variables for the node application configurations.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl setenv nodeapps command with the following syntax model:
srvctl setenv nodeapps {-namevals "name=val[,name=val][...]" |
-nameval "name=val"} [-viponly] [-gsdonly] [-onsonly] [-verbose]
Table A-95
srvctl setenv nodeapps Parameters
Parameter
-envs "name=val[,name=val]
[...]"
Description
Comma-delimited list of name-value pairs of
environment variables
-env "name=val"
Enables single environment variable to be set to a
value that contains commas or other special characters
-viponly
Modify only the VIP configuration
-gsdonly
Modify only the GSD configuration
-onsonly
Modify only the ONS daemon configuration
Server Control Utility Reference A-109
SRVCTL Command Reference
Table A-95
(Cont.) srvctl setenv nodeapps Parameters
Parameter
Description
Verbose output
-verbose
Example
To set an environment variable for all node applications:
$ srvctl setenv nodeapps -env "CLASSPATH=/usr/local/jdk/jre/rt.jar" -verbose
srvctl setenv vip
Administers cluster VIP environment configurations.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl setenv vip command with the following syntax:
srvctl setenv vip -vip vip_name {-envs "name=val[,name=val,...]" |
-env "name=val"} [-verbose]
Table A-96
srvctl setenv vip Parameters
Parameter
-vip vip_name
Description
Name of the VIP
-envs "name=val,..."
Comma-delimited list of name-value pairs of environment
variables
-env "name=val"
Enables single environment variable to be set to a value
that contains commas or other special characters
-verbose
Verbose output
Example
The following example sets the language environment configuration for a cluster VIP:
$ srvctl setenv vip -vip crm1-vip -env "LANG=en"
start
A summary list of srvctl start commands and their descriptions.
Starts Oracle Restart or Oracle Clusterware enabled, non-running applications for the
database, all or named instances, all or named service names, or node-level
applications. For the start command, and for other operations that use a connect
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string, if you do not provide a connect string, SRVCTL uses /as sysrac to perform
the operation. To run such operations, the owner of the oracle binary executables
must be a member of the OSRAC group, and users running the commands must also
be in the OSRAC group.
Table A-97
srvctl start Summary
Command
Description
srvctl start
database
Starts the cluster database and its instances
srvctl start
diskgroup
Starts a specified disk group on a number of nodes
srvctl start home
Starts Oracle Clusterware-managed or Oracle Restart-managed
resources in a specific Oracle home
srvctl start
instance
Starts the instance
srvctl start
listener
Starts the specified listener or listeners
srvctl start
nodeapps
Starts the node applications
srvctl start ons
Starts the Oracle Notification Service daemon for Oracle Restart
srvctl start scan
Starts all SCAN VIPs
srvctl start
scan_listener
Starts all SCAN listeners
srvctl start
service
Starts a service
srvctl start vip
Starts a VIP
srvctl start
volume
Starts an enabled volume
srvctl start database
Starts a cluster database and its enabled instances and all listeners on nodes with
database instances. You can disable listeners that should not be started.
Syntax and Parameters
Use the srvctl start database command with the following syntax:
srvctl start database -db db_unique_name [-eval]
[-startoption start_options] [-stopconcurrency number_of_instances] [-node
node_name]
Table A-98
srvctl start database Parameters
Parameter
-db db_unique_name
Description
Unique name for the database
Server Control Utility Reference A-111
SRVCTL Command Reference
Table A-98
(Cont.) srvctl start database Parameters
Parameter
Description
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
-startoption
start_options
Options for startup command (for example: OPEN, MOUNT, or
NOMOUNT)
Notes:
•
•
This command parameter supports all database startup
options.
For multi-word startup options, such as read only and
read write, separate the words with a space and enclose
in double quotation marks (""). For example, "read
only".
See Also: SQL*Plus User's Guide and Reference for more
information about startup options
[-startconcurrency
number_of_instances]
-node node_name
Specify a number of database instances to start simultaneously,
or specify 0 for an empty start concurrency value.
The name of the node on which you want to start the database
Notes:
•
•
•
•
•
This command only applies to Oracle RAC One Node
databases.
The node you specify must be in the candidate list for an
administrator-managed Oracle RAC One Node database
or in the server pool for a policy-managed Oracle RAC
One Node database.
If the database is already running on a node than the one
you specify, then the command returns an error.
If you do not specify a node, then Oracle Clusterware
chooses which node on which to start the Oracle RAC One
Node database according to its policies, such as dispersion,
number of resources, and order of candidate nodes.
If there is an active online database relocation for the
Oracle RAC One Node database you are attempting to
start, then both instances will already be running and the
command returns an error message saying so (remember
that only during an online database relocation are two
instances of an Oracle RAC One Node database in
existence).
If the online database relocation failed for the Oracle RAC
One Node database and you do not specify a node, then
the command attempts to start both database instances.
If the online database relocation failed for the Oracle RAC
One Node database and you specify a node, then the
command attempts to abort the failed relocation and start
the instance on that node.
Example
An example of this command is:
$ srvctl start database -db crm -startoption "read only"
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srvctl start diskgroup
Start a a specific disk group resource on a number of specified nodes.
Syntax and Parameters
Use the srvctl start diskgroup command with the following syntax:
srvctl start diskgroup -diskgroup diskgrp_name [-node "node_list"]
Table A-99
srvctl start diskgroup Parameters
Parameter
Description
-diskgroup diskgrp_name
-node "node_list"
The Oracle ASM disk group name
Comma-delimited list of node names on which to start the disk
group resource
Note: This parameter can be used only with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl start diskgroup -diskgroup diskgroup1 -node "mynode1,mynode2"
srvctl start home
Starts all the Oracle Restart-managed or Oracle Clusterware-managed resources on the
specified Oracle home.
Syntax and Parameters
Use the srvctl start home command with the following syntax:
srvctl start home -oraclehome Oracle_home -statefile state_file -node node_name
Table A-100
srvctl start home Parameters
Parameter
Description
-oraclehome Oracle_home
The path to the Oracle home for which you want to start
the Oracle Restart or Oracle Clusterware-managed
resources.
-statefile state_file
-node node_name
The path name where you want the state file to be written.
The name of the node where the Oracle home resides.
Note: This parameter can be used only with Oracle
Clusterware.
Example
An example of this command is:
$ srvctl start home -oraclehome /u01/app/oracle/product/12.1.0/db_1
-statefile ~/state.txt -node node1
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SRVCTL Command Reference
srvctl start instance
Starts instances in the cluster database.
Use the srvctl start instance command to start database instances, and all
listeners on nodes with database instances
Syntax
Use the srvctl start instance command with one of these syntax models:
srvctl start instance -db db_unique_name -node node_name
[-instance "instance_name"] [-startoption start_options]
srvctl start instance -db db_unique_name -instance "inst_name_list"
[-startoption start_options]
Parameters
Table A-101
srvctl start instance Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
-node node_name
The name of a single node.
Note: Use this parameter for policy-managed databases.
-instance
{ "instance_name"
|
"inst_name_list" }
The name of a single instance or a comma-delimited list of
instance names
-startoption
start_options
Options for startup command, such as OPEN, MOUNT, or NOMOUNT)
Note: Use this parameter for administrator-managed databases.
Note: For multi-word startup options, such as read only and
read write, separate the words with a space and enclose in
double quotation marks (""). For example, "read only".
Usage Notes
•
This command is only available with Oracle Clusterware and Oracle RAC.
•
If you run this command on an Oracle RAC One Node database, then the
command returns an error instructing you to use the database noun, instead.
Related Topics:
SQL*Plus User's Guide and Reference
srvctl start listener
Starts the default listener on specific node, or starts the specified listener on all nodes
that are registered with Oracle Clusterware or on the given node.
Syntax
srvctl start listener [-node node_name] [-listener listener_name]
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Parameters
Table A-102
srvctl start listener Command Parameters
Parameter
Description
-node node_name
Specify a particular node name to start the listener on that node.
Note: You can only use this parameter with Oracle Clusterware.
-listener
listener_name
Specify a particular listener name. Use the srvctl config listener
command to obtain the name of a listener.
If you do not assign a value to this parameter, then SRVCTL starts
all known listeners in the cluster.
Examples
An example of this command is:
$ srvctl start listener -listener LISTENER_LEAF
srvctl start nodeapps
Starts node-level applications on a node or all nodes in the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start nodeapps command with the following syntax:
srvctl start nodeapps [-node node_name] [-gsdonly] [-adminhelper] [-verbose]
Table A-103
srvctl start nodeapps Parameters
Parameter
Description
-node node_name
-gsdonly
-adminhelper
-verbose
Node name
If you do not specify this parameter, then the utility starts the
nodeapps on all active nodes in the cluster.
Starts only GSD instead of all node applications
Starts only an Administrator helper instead of all node
applications
Verbose output
Example
An example of this command is:
$ srvctl start nodeapps
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SRVCTL Command Reference
srvctl start ons
Starts the Oracle Notification Service daemon.
Note:
This command is only available with Oracle Restart.
Syntax and Parameters
Use the srvctl start ons command with the following syntax:
srvctl start ons [-verbose]
There is only one parameter for this command, -verbose, which is used to indicate
that verbose output should be displayed.
srvctl start scan
Starts all SCAN VIPs, by default, or a specific SCAN VIP, on all nodes or a specific
node in the cluster.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start scan command with the following syntax:
srvctl start scan [-scannumber ordinal_number] [-node node_name]
Table A-104
srvctl start scan Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN VIP you
want to start. The range of values you can specify for this
parameter is 1 to 3.
If you do not specify this parameter, then the utility
starts all the SCAN VIPs.
-node node_name
The name of a single node.
If you do not specify this parameter, then the utility
starts the SCAN VIPs on all nodes in the cluster.
Example
To start the SCAN VIP identified by the ordinal number 1 on the crm1 node, use the
following command:
$ srvctl start scan -scannumber 1 -node crm1
srvctl start scan_listener
Starts all SCAN listeners, by default, or a specific listener on all nodes or a specific
node in the cluster.
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Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start scan_listener command with the following syntax:
srvctl start scan_listener [-node node_name] [-scannumber ordinal_number]
Table A-105
srvctl start scan_listener Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN
Listener you want to start. The range of values you can
specify for this parameter is 1 to 3.
If you do not specify this parameter, then the utility
starts all the SCAN listeners.
The name of a single node.
-node node_name
If you do not specify this parameter, then the utility
starts the SCAN listeners on all nodes in the cluster.
Example
An example of this command is:
$ srvctl start scan_listener -scannumber 1
srvctl start service
Starts a service or multiple services on a database, pluggable database, or instance.
Syntax
srvctl start service [-db db_unique_name] [-service "services_list"
[-pq] | -pdb pluggable_database | -serverpool pool_name]
[-node node_name | -instance instance_name]
[-global_override] [-startoption start_options] [-eval] [-verbose]
Parameters
Parameter
Description
-db db_unique_name
Specify a unique name for the database.
-service
"service_list"
Specify a service name or a comma-delimited list of service names
enclosed in double quotation marks ("").
If you do not include this parameter, then SRVCTL starts all of the
services for the specified database.
Note: All manual service startup must specify the name of the
service to be started by the user.
-pq
Specify this parameter to restrict the start action to a parallel query
service.
Server Control Utility Reference A-117
SRVCTL Command Reference
Parameter
Description
-pdb
pluggable_database
Specify the name of a pluggable database. Optionally, you can
specify either the name of a node or the name of an instance to
restrict the starting of services to that particular object on the
pluggable database.
-serverpool
pool_name
Alternative to using the -pq parameter, you can specify the name
of a server pool that contains the services you want to start. Use
this parameter for policy-managed databases.
-node node_name
Specify the name of a node where the services reside that you
want to start. Use this parameter for policy-managed databases.
-instance
instance_name
Specify the name of an instance where the services reside that you
want to start. Use this parameter for administrator-managed
databases.
-global_override
Override value to operate on a global service. Use this parameter
only with global services; this parameter is ignored if specified for
a non-global service.
-startoption
start_options
Specify startup options used when service startup requires
starting a database instance. Options include OPEN, MOUNT, and
NOMOUNT.
Note: For multi-word startup options, such as read only and
read write, separate the words with a space and enclose in
double quotation marks (""). For example, "read only".
–verbose
Display verbose output.
Usage Notes
•
The srvctl start service command will fail if you attempt to start a service
that is already running.
•
The srvctl start service command will fail if you attempt to start a service
on an instance, if that service is already running on its maximum number of
instances, that is, its number of preferred instances.
•
You can move a service or change the status of a service on an instance with the
srvctl modify service and srvctl relocate service commands.
Examples
The following example starts all services on a specific database:
$ srvctl start database -db myDB
The following examples start a list of services (optionally restricted to a parallel query
services in the latter example) regardless of the pluggable database on which they may
reside:
$ srvctl start database -db myDB -service "myServ01,myServ02"
$ srvctl start database -db myDB -service "myServ01,myServ02" -pq
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The following example starts all services in a given server pool:
$ srvctl start database -db myDB -serverpool myServerPool
The following examples start all services on a given pluggable database, optionally
restricted to a single node or a single instance in the latter two examples, repectively:
$ srvctl start service -db myDB -pdb myPDB1
$ srvctl start service -db myDB -pdb myPDB1 -node myRACNode01
$ srvctl start service -db myDB -pdb myPDB1 -instance myDB01
The following example starts all services, for a given database, on a given instance (for
all pluggable databases):
$ srvctl start service -db myDB -instance myDB01
The following example start all services for a given database on a given node (for all
pluggable databases):
$ srvctl start service -db myDB -node myRACNode01
The following examples start a list of services on a given node or given instance:
$ srvctl start service -db myDB -service "myService01,myService02" -node myRACNode01
$ srvctl start service -db myDB -service "myService01,myService02" -instance myDB01
srvctl start vip
Starts a specific VIP or a VIP on a specific node.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start vip command with the following syntax:
srvctl start vip {-node node_name | -vip vip_name } [-verbose]
Table A-106
srvctl start vip Parameters
Parameter
-node node_name
-vip vip_name
-verbose
Description
Node name
The VIP name
Verbose start
Example
An example of this command is:
$ srvctl start vip -vip crm1-vip -verbose
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SRVCTL Command Reference
srvctl start volume
Starts a specific, enabled volume.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start volume command with the following syntax:
srvctl start volume {-volume volume_name -diskgroup disk_group_name |
-device volume_device} [-node node_list]
Table A-107
srvctl start volume Parameters
Parameter
Description
-volume volume_name
Specify the name of the volume that you want to start. This
parameter is required.
-diskgroup
disk_group_name
-device volume_device
-node node_list
Specify the name of the disk group in which the volume that
you want to start resides.
Specify the path to the volume device that you want to start.
Specify a comma-delimited list of node names where volumes
that you want to start reside.
Usage Notes
The srvctl start volume command does not create a volume service. Provided
that the volume already exists and the volume resource is enabled, SRVCTL attempts
to start it. If the volume exists but the resource is disabled, then srvctl start
volume returns an error.
Example
The following example starts a volume named VOLUME1 that resides in a disk group
named DATA:
$ srvctl start volume -volume VOLUME1 -diskgroup DATA
status
Displays the current state of a named database, instances, services, disk group,
listener, node application, or other resource managed by Oracle Clusterware.
If you use the -verbose parameter with the status command, then SRVCTL displays
the INTERNAL_STATE, which indicates actions in progress by Oracle Clusterware,
such as starting, stopping, or cleaning. If the internal state is STABLE, then the verbose parameter displays nothing because this is the normal state. Additionally,
the -verbose parameter displays STATE_DETAILS, which may indicate additional
information provided by the resource about why it is in its current state
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Table A-108
srvctl status Summary
Command
Description
srvctl status database
Displays the status of a database
srvctl status diskgroup
Displays the status of a specific disk group on a number of nodes
srvctl status home
Displays the status of the resources associated with the specified
Oracle home
srvctl status instance
Displays the status of a instance
srvctl status listener
Displays the status of a listener resource
srvctl status nodeapps
Displays the status of node applications
srvctl status ons
Displays the status of Oracle Notification Service
srvctl status scan
Displays the status of SCAN VIPs
srvctl status
scan_listener
Displays the status of SCAN listeners
srvctl status server
Displays the status of servers
srvctl status service
Displays the status of services
srvctl status srvpool
Displays the status of server pools
srvctl status vip
Displays the status of VIPs
srvctl status volume
Displays the status of volumes
srvctl status database
This command displays the current state of the of the database.
Syntax
srvctl status database {-db db_unique_name {[-serverpool serverpool_name]
| [-sid] [-home]} | -serverpool serverpool_name | -thisversion | -thishome}
[-force] [-detail] [-verbose]
Parameters
Table A-109
srvctl status database Parameters
Parameter
Description
-db db_unique_name
Specify a unique name for the database.
-serverpool
serverpool_name
Optionally, you can specify a server pool that SRVCTL will
display information on nodes contained within.
–sid
Use this parameter to display the SID of the Oracle instance
running on this node.
Server Control Utility Reference A-121
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Table A-109
(Cont.) srvctl status database Parameters
Parameter
Description
–home
Use this parameter to display the Oracle home of the specified
database.
-thisversion
Use this parameter to display the status of databases that are of
the same Oracle product version as SRVCTL.
-thishome
Use this parameter to display the status of databases that are
configured in this Oracle home.
-force
Include disabled applications
–detail
Use this parameter to display detailed database status
information.
-verbose
Displays STATE_DETAILS and INTERNAL_STATE attributes,
which include STABLE, STARTING, STOPPING, and CLEANING.
If the INTERNAL_STATE is STABLE, then SRVCTL displays no
additional information. If the INTERNAL_STATE is STARTING,
then SRVCTL displays:
Instance {0} is being started
If the INTERNAL_STATE is CLEANING, then SRVCTL displays:
Instance {0} is being cleaned up
Usage Notes
The output of this command includes information on the Oracle ASM or Oracle ASM
IOServer instance for each running instance of the database.
Examples
This command displays output similar to the following:
$ srvctl status database -db db00 -detail
Instance {0} is connected to ASM instance {1}
Instance {0} is connected to ASM I/O server instance {1}
srvctl status diskgroup
Displays the status of a specific disk group on a number of specified nodes.
Syntax and Parameters
Use the srvctl status diskgroup command with the following syntax:
srvctl status diskgroup -diskgroup diskgroup_name [-node "node_list"]
[-detail] [-verbose]
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Table A-110
srvctl status diskgroup Parameters
Parameter
Description
-diskgroup diskgroup_name
-node node_list
The Oracle ASM disk group name
Comma-delimited list of node names on which to check
status of the disk group
Note: This parameter can be used only with Oracle
Clusterware.
Display detailed status information for the disk group
-detail
Displays verbose output.
-verbose
Example
An example of this command is:
$ srvctl status diskgroup -diskgroup dgrp1 -node "mynode1,mynode2" -detail
srvctl status home
Displays the status of all the Oracle Restart-managed or Oracle Clusterware-managed
resources for the specified Oracle home.
Syntax and Parameters
Use the srvctl status home command with the following syntax:
srvctl status home -oraclehome Oracle_home -statefile state_file -node node_name
Table A-111
srvctl status home Parameters
Parameter
Description
-oraclehome Oracle_home
The path to the Oracle home for which you want to start
the Oracle Restart or Oracle Clusterware-managed
resources
-statefile state_file
The path name for the text file that holds the state
information generated by this command.
-node node_name
The name of the node where the Oracle home resides.
Note: This parameter is required and can be used only
with Oracle Clusterware.
Example
An example of this command is:
$ srvctl status home -oraclehome /u01/app/oracle/product/12.1/dbhome_1 -statefile
~/state.txt -node stvm12
The preceding command returns output similar to the following:
Server Control Utility Reference A-123
SRVCTL Command Reference
Database cdb1 is running on node stvm12
srvctl status instance
The srvctly status instance command displays the status of Oracle database
instances.
The output of this command includes information about the Oracle ASM or Oracle
ASM IOServer instance for each running instance of the database.
Syntax
srvctl status instance -db db_unique_name {-node node_name
| -instance "instance_name_list"} [-detail] [-force] [-verbose]
Parameters
Table A-112
srvctl status instance Parameters
Parameter
Description
-db db_unique_name
Unique name for the database.
-node node_name
Node name.
Note: Use this parameter for policy-managed databases.
-instance
"inst_name_list"
Comma-delimited list of instance names.
-detail
Use this parameter to display detailed status information.
-force
Include disabled applications
-verbose
Displays verbose output
Note: Use this parameter for administrator-managed databases.
Example
This command displays output similar to the following:
$ srvctl status instance -db db00 -node node10 -verbose
Instance db0010 running on node node10 is connected to ASM I/O Server instance +IOS1
srvctl status listener
Displays the status of listener resources.
Syntax and Parameters
Use the srvctl status listener command with the following syntax:
srvctl status listener [-listener listener_name] [-node node_name] [-verbose]
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Table A-113
srvctl status listener Parameters
Parameter
-listener listener_name
-node node_name
-verbose
Description
Name of a listener.
If you do not specify this parameter, then the listener name
defaults to LISTENER
Name of a cluster node.
Note: This parameter can be used only for Oracle Clusterware.
Displays verbose output.
Example
To display the status of the default listener on the node node2, use the following
command:
$ srvctl status listener -node node2
srvctl status nodeapps
Displays the status of node applications.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl status nodeapps command with the following syntax:
srvctl status nodeapps [-node node_name]
You can optionally specify the node for which to display the status of the node
applications.
srvctl status ons
Displays the current state of the Oracle Notification Service daemon.
Note:
This command is only available with Oracle Restart.
Syntax and Parameters
Use the srvctl status ons command with the following syntax:
srvctl status ons
srvctl status scan
Displays the status for all SCAN VIPs, by default, or a specific SCAN VIP.
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Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl status scan command with the following syntax:
srvctl status scan [-scannumber ordinal_number] [-verbose]
Table A-114
srvctl status scan Parameters
Parameter
Description
-scannumber ordinal_number
Specify an ordinal number that identifies a specific SCAN
VIP. The range of values you can specify for this parameter
is 1 to 3. If you do not specify this parameter, then the
utility displays the status of all SCAN VIPs in the cluster.
Displays verbose output.
-verbose
Example
An example of this command is:
$ srvctl status scan -scannumber 1
srvctl status scan_listener
Displays the status for all SCAN listeners, by default, or a specific listener.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl status scan_listener command with the following syntax:
srvctl status scan_listener [-scannumber ordinal_number] [-verbose]
Table A-115
srvctl status scan_listener Parameters
Parameter
-scannumber ordinal_number
-verbose
Description
Specify an ordinal number that identifies a specific SCAN
VIP. The range of values you can specify for this
parameter is 1 to 3. If you do not specify this parameter,
then the utility displays the status of all SCAN VIPs in the
cluster.
Displays verbose output.
Example
An example of this command is:
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$ srvctl status scan_listener -scannumber 1
srvctl status server
Displays the current state of named servers.
Syntax and Parameters
Use the srvctl status server command with the following syntax:
srvctl status server -server "server_name_list" [-detail]
Table A-116
srvctl status server Parameters
Parameter
Description
-server "server_name_list"
Comma-delimited list of server names.
Print detailed status information.
-detail
Example
The following example displays the status of a named server:
$ srvctl status server -server "server11" -detail
srvctl status service
Displays the status of a service.
For Oracle RAC One Node databases, if there is an online database relocation in
process, then the srvctl status service command displays the source and
destination nodes and the status of the relocation, whether it is active or failed.
Syntax and Parameters
Use the srvctl status service command with the following syntax:
srvctl status service -db db_unique_name [-service "service_name_list"]
[-force] [-verbose]
Table A-117
srvctl status service Parameters
Parameter
-db db_unique_name
-services "service_name_list"
-force
-verbose
Description
Unique name for the database
Comma-delimited list of service names.
If you do not specify this parameter, then the utility
lists the status of all services for the specified
database.
Include disabled applications
Displays verbose output.
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Example
The following example displays the status of a named service across the clustered
database:
$ srvctl status service -db crm -service "crm" -verbose
srvctl status srvpool
Displays server pool names, number of servers in server pools, and, optionally, the
names of the servers in the server pools.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl status srvpool command with the following syntax:
srvctl status srvpool [-serverpool pool_name] [-detail]
Table A-118
srvctl status srvpool Parameters
Parameter
-serverpool pool_name
-detail
Description
Name of the server pool
Print detailed status information
Usage Notes
•
If you include the -detail parameter but do not specify a specific server pool
with the -serverpool parameter, then the output of this command includes the
names of servers that are currently assigned to each server pool.
•
If you use the -serverpool parameter to specify a server pool, then the output
for this command includes the server pool name and number of servers in the
server pool (and, optionally, the server names) for the specified server pool.
Example
An example of this command is:
$ srvctl status srvpool -serverpool srvpool1 -detail
srvctl status vip
Displays status for a specific VIP or a VIP on a specific node.
Note:
This command is only available with Oracle Clusterware.
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Syntax and Parameters
Use the srvctl status vip command with the following syntax:
srvctl status vip {-node node_name | -vip vip_name} [-verbose]
Table A-119
srvctl status vip Parameters
Parameter
Description
Node name
-node node_name
The VIP name
-vip vip_name
Displays verbose output.
-verbose
Example
An example of this command is:
$ srvctl status vip -vip node1-vip
srvctl status volume
Displays the status of a specific volume or all volumes.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl status volume command with the following syntax:
srvctl status volume [-device volume_device] [-volume volume_name]
[-diskgroup disk_group_name] [-node "node_list"]
Table A-120
srvctl status volume Parameters
Parameter
Description
-device volume_device
Specify the path to the volume device for which you want
to display the status.
-volume volume_name
Specify the name of the volume for which you want to
view the status.
-diskgroup disk_group_name
Specify the name of the disk group in which the volume
resides for which you want to display the status.
-node "node_list"
Specify a comma-delimited list of node names where
volumes for which you want to view the status reside.
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SRVCTL Command Reference
Usage Notes
•
If you do not specify any of the optional parameters, then SRVCTL displays the
status for all volumes.
•
If you specify only the -volume parameter, then SRVCTL displays the status for
the volume that you specify.
•
If you specify only the -diskgroup parameter, then SRVCTL displays the status
for the volumes that reside in the disk group that you specify.
•
If you specify only the -device parameter, then SRVCTL displays the status for
the volume device that you specify.
•
If you specify the -diskgroup and -device parameters, then SRVCTL displays
the status for the volume device in the disk group that you specify.
•
If you specify the -node parameter, then SRVCTL displays the status of the
volumes that reside on the nodes you list.
Examples
The srvctl status volume command displays information similar to the
following:
$ srvctl status volume –volume vol1
Volume vol1 of diskgroup diskgrp1 for device volume_device_path1 is enabled
Volume vol1 of diskgroup diskgrp1 for device volume_device_path1 is running
In the preceding example, SRVCTL performs a status query on all nodes because the node parameter is not specified.
$ srvctl status volume
Volume vol1 of diskgroup
Volume vol1 of diskgroup
Volume vol2 of diskgroup
Volume vol2 of diskgroup
diskgrp
diskgrp
diskgrp
diskgrp
for
for
for
for
device
device
device
device
volume_device_path1
volume_device_path1
volume_device_path2
volume_device_path2
is
is
is
is
enabled
running
enabled
running
In the preceding example, SRVCTL displays the status of all registered volumes
because the no parameter is specified.
stop
Stops the Oracle Clusterware applications for the database, all or named instances, all
or named service names, listeners, or node-level application resources.
Only the Oracle Clusterware applications that are enabled, starting or running are
stopped. Objects running outside of Oracle Clusterware are not stopped.
You should disable an object that you intend to remain stopped after you issue a
srvctl stop command. See the srvctl disable command.
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Note:
•
If the object is stopped and is not disabled, then it can restart as the result
of another planned operation. The object does not restart because of a
failure. Oracle recommends that you disable any object that should
remain stopped after you issue a stop command.
•
When you use the -force parameter to stop dependent applications and
the object, then those dependent applications do not restart when the
object is later restarted or after the node fails. You must restart the
dependent applications, manually, except for services with AUTOMATIC
management policy when a database is stopped.
Table A-121
srvctl stop Summary
Command
Description
srvctl stop
database
Stops the cluster database
srvctl stop
diskgroup
Stops a specific disk group on a specified number of nodes
srvctl stop home
Stops the resources for the specified Oracle home
srvctl stop
instance
Stops the instance
srvctl stop
listener
Stops the specified listener or listeners
srvctl stop
nodeapps
Stops the node-level applications
srvctl stop ons
Stops Oracle Notification Service
srvctl stop scan
Stops all SCAN VIPs
srvctl stop
scan_listener
Stops all SCAN listeners
srvctl stop
service
Stops the service
srvctl stop vip
Stops VIP resources
srvctl stop volume
Stops a volume device
srvctl stop database
The srvctl stop database command stops a database, its instances, and its
services.
Syntax
srvctl stop database -db db_unique_name [-stopoption stop_options]
[-stopconcurrency number_of_instances] [-drain_timeout timeout] [-eval]
[-force] [-verbose]
Server Control Utility Reference A-131
SRVCTL Command Reference
Parameters
Table A-122
srvctl stop database Command Parameters
Parameter
Description
-db db_unique_name
Specify the unique name for the database that you want to stop.
-stopoption
stop_options
Specify options for the shutdown command, such as NORMAL,
TRANSACTIONAL LOCAL, IMMEDIATE, or ABORT.
-stopconcurrency
number_of_instance
s
Specify a number of database instances to stop simultaneously, or
specify 0 for an empty stop concurrency value.
-drain_timeout
timeout
The time, in seconds, allowed to complete the resource draining
action. By default, this parameter is not set. You can specify 0 or
any positive integer. An empty string unsets the parameter. If you
specify zero, then the agent will perform the actions related to
service draining, immediately.
Drain timeout is the maximum time the service waits before
exiting (in case of srvctl stop service or srvctl stop
instance) or proceeding to stop database (srvctl stop
database), until the draining of sessions is completed. If session
draining completes in 10 seconds and the drain timeout value (on
CLI or resource attribute) is 100 seconds, then SRVCTL moves on
after 10 seconds. It does not wait for the remaining 90 seconds.
-eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
-force
This parameter stops the database, its instances, its services, and
any resources that depend on those services.
—verbose
Display verbose output.
Example
The following command example stops a database and includes verbose output:
$ srvctl stop database -db db1 -drain_timeout 50 -verbose
Draining in progress on services svc1,svc2.
Drain complete on services svc1.
Draining in progress on services svc2.
Draining in progress on services svc2.
Drain complete on services svc2.
srvctl stop diskgroup
Use this command to stop a specific disk group resource on a number of specified
nodes.
Syntax and Parameters
Use the srvctl stop diskgroup command with the following syntax:
srvctl stop diskgroup -diskgroup diskgroup_name [-node "node_list"] [-force]
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Table A-123
srvctl stop diskgroup Parameters
Parameter
Description
-diskgroup diskgroup_name
-node "node_list"
The Oracle ASM disk group name
Comma-delimited list of node names on which to stop
the disk group resource
Note: This parameter can be used only with Oracle
Clusterware.
This parameter does not stop the databases that depend
on the disk group you are stopping, but instead performs
a forceful dismount that may cause those databases to
fail.
-force
Example
An example of this command is:
$ srvctl stop diskgroup -diskgroup diskgroup1 -node "mynode1,mynode2" -force
srvctl stop home
Stops all the Oracle Restart-managed or Oracle Clusterware-managed resources that
run from the specified Oracle home.
Syntax and Parameters
Use the srvctl stop home command with the following syntax:
srvctl stop home -oraclehome Oracle_home -statefile state_file -node node_name
[-stopoption stop_options] [-force]
Table A-124
srvctl stop home Parameters
Parameter
Description
-oraclehome Oracle_home
The path to the Oracle home for which you want to
start the Oracle Restart or Oracle Clusterware-managed
resources.
Note: The path to the Oracle home you specify must be
the same version as the Oracle home from which you
invoke SRVCTL.
-statefile state_file
-node node_name
-stopoption stop_options
The path name where you want the state file to be
written.
The name of the node where the Oracle home resides.
Note: This parameter can be used only with Oracle
Clusterware.
Shutdown options for the database, such as NORMAL,
TRANSACTIONAL, IMMEDIATE, or ABORT
See Also: SQL*Plus User's Guide and Reference for more
information about shutdown options
Server Control Utility Reference A-133
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Table A-124
(Cont.) srvctl stop home Parameters
Parameter
Description
Stop the resources even if errors are reported.
-force
Example
An example of this command is:
$ srvctl stop home -oraclehome /u01/app/oracle/product/12.1.0/db_1 -statefile
~/state.txt
srvctl stop instance
The srvctl stop instance command stops instances and stops any services
running on specified instances.
Syntax
srvctl stop instance -db db_unique_name {-node node_name
| -instance "instance_name_list"} [-stopoption stop_options]
[-drain_timeout timeout] [-force] [-failover] [-verbose]
Parameters
Table A-125
srvctl stop instance Command Parameters
Parameter
Description
-db db_unique_name
-node node_name
-instance
"instance_name_lis
t"
-stopoption
stop_options
-drain_timeout
timeout
-force
–failover
-verbose
Usage Notes
If you run this command on an Oracle RAC One Node database, then the command
returns an error instructing you to use the srvctl stop database command,
instead.
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Example
The following command example stops instances in an administrator-managed
database and includes verbose output:
$ srvctl stop instance -db db1 -instance inst1 -drain_timeout 50 -verbose
Draining in progress on services svc1
Draining in progress on services svc1
Drain complete on services svc1
Related Topics:
SQL*Plus User's Guide and Reference
srvctl stop listener
Stops the default listener or a specific listener on all nodes or the specified node.
You can also use this command to stop a listener on a non-cluster database from the
non-cluster database home. However, SRVCTL does not accept the -node parameter
when run from a non-cluster database home.
Syntax
srvctl stop listener [-listener listener_name] [-node node_name] [-force]
Parameters
Table A-126
srvctl stop listener Command Parameters
Parameter
Description
-listener
listener_name
Specify the name of the listener you want to stop.
-node node_name
Optionally, you can specify the name of a single node on which a
particular listener runs.
If you do not assign a value to this parameter, then SRVCTL stops
all known listeners in the cluster.
Note: You can only use this parameter with Oracle Clusterware.
–force
Forcibly stop the listener.
Examples
The following command stops all listeners on the node mynode1:
$ srvctl stop listener -node mynode1
srvctl stop nodeapps
Stops node-level applications on a node in the cluster.
Note:
This command is only available with Oracle Clusterware.
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Syntax and Parameters
Use the srvctl stop nodeapps command with the following syntax:
srvctl stop nodeapps [-node node_name] [-gsdonly] [-adminhelper] [-force]
[-relocate] [-verbose]
Table A-127
srvctl stop nodeapps Parameters
Parameter
-node node_name
-gsdonly
-adminhelper
-relocate
Description
Node name
If you do not specify this parameter, then the utility stops the
node applications (nodeapps) on all active nodes in the cluster.
Stops only the GSD instead of all nodeapps
Stops only the Administrator helper instead of all nodeapps
Relocate VIP and possibly dependent services
Note: If you specify this parameter, then you must also specify
the -node node_name parameter.
Force stop
-force
-verbose
Display verbose output
Example
An example of this command is:
$ srvctl stop nodeapps
srvctl stop ons
Stops the Oracle Notification Service daemon.
Note:
This command is only available with Oracle Restart.
Syntax and Parameters
Use the srvctl stop ons command with the following syntax:
srvctl stop ons [-verbose]
The only parameter for this command is the -verbose parameter, which specifies
that verbose output should be displayed.
Example
An example of this command is:
$ srvctl stop ons -verbose
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srvctl stop scan
Stops all SCAN VIPs, by default, that are running or in starting state, or stops a
specific SCAN VIP identified by ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl stop scan command with the following syntax:
srvctl stop scan [-scannumber ordinal_number] [-force]
Table A-128
srvctl stop scan Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN VIP you
want to stop. The range of values you can specify for
this parameter is 1 to 3.
If you do not specify this parameter, then the utility
stops all the SCAN VIPs.
Force stop of the SCAN VIP.
-force
Example
An example of this command is:
$ srvctl stop scan -scannumber 1
srvctl stop scan_listener
Stops all SCAN listeners, by default, that are in a running or starting state, or a specific
listener identified by ordinal_number.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl start scan_listener command with the following syntax:
srvctl stop scan_listener [-scannumber ordinal_number] [-force]
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Table A-129
srvctl stop scan_listener Parameters
Parameter
Description
-scannumber ordinal_number
An ordinal number that identifies which SCAN listener to
stop. You can specify values of 1, 2, or 3 for this
parameter.
If you do not specify this parameter, then the utility stops
all the SCAN listeners.
Force stop of the SCAN listener.
-force
Example
An example of this command is:
$ srvctl stop scan_listener -scannumber 1
srvctl stop service
The srvctl stop service command stops one or more services globally across the
cluster database, or on the specified instance.
Syntax
srvctl stop service {-node node_name | -db db_unique_name [-pq] [-pdb
pluggable_database |
-service "service_list" [-eval]] [-node node_name | -instance instance_name |}
-serverpool pool_name] [-stopoption IMMEDIATE|TRANSACTIONAL|NONE] [-drain_timeout
timeout]
[-wait {YES | NO}] [-force [-noreplay]] [-global_override] [-verbose]
Parameters
Table A-130
srvctl stop service Command Parameters
Parameter
Description
-node node_name
Optionally, you can specify the name of the node on which you
want to stop services. Use this parameter to stop all services on a
specific node. Use this parameter for policy-managed databases.
-db db_unique_name
Specify a unique name for the database.
-pdb
pluggable_database
Alternatively, use this parameter to stop services running on a
specific pluggable database.
-service
"service_list"
Specify a particular service or a comma-delimited list of service
names enclosed in double quotation marks ("") you want to stop.
If you do not provide a service name list, then SRVCTL stops all
services on the database or on a specific instance.
-pq
Specify this parameter to restrict the stop action to a parallel query
service.
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Table A-130
(Cont.) srvctl stop service Command Parameters
Parameter
Description
-instance
instance_name
Optionally, you can specify the name of the instance for which
you want to stop services. Use this parameter for administratormanaged databases.
-serverpool
pool_name
Optionally, you can specify the name of the server pool that
contains the service you want to stop.
—eval
Use this parameter to hypothetically evaluate the impact of the
command on the system.
-stopoption
IMMEDIATE|
TRANSACTIONAL|NONE
Optionally, you can specify the mode in which the service is
stopped. If you set this parameter on the service, then this value is
used if you do not set the value on the command line.
IMMEDIATE terminates the sessions after the drain timeout
interval expires.
TRANSACTIONAL permits sessions to drain for the amount of time
specified in the -drain_timeout parameter. The sessions are
then terminated immediately when the drain timeout interval
expires.
If you specify NONE, then no sessions are terminated.
The default is taken from the service setting, when specified on
the service. Otherwise the default is NONE.
-drain_timeout
timeout
Specify the time, in seconds, allowed for resource draining to be
completed. Accepted values are an empty string (""), 0, or any
positive integer. The default value is an empty string, which
means that this parameter is not set. If it is set to 0, then draining
occurs, immediately.
The draining period is intended for planned maintenance
operations. During the draining period, all current client requests
are processed, but new requests are not accepted. When set on the
service this value is used when the command line value is not set.
-wait YES | NO
Choose YES to wait until service draining is completed on the
node to stop the service.
Server Control Utility Reference A-139
SRVCTL Command Reference
Table A-130
(Cont.) srvctl stop service Command Parameters
Parameter
Description
-force [-noreplay]
Force SRVCTL to stop the service; this causes SRVCTL to
disconnect all of the sessions using the stop option you specify
(IMMEDIATE or TRANSACTIONAL), requiring the sessions
using the service to reconnect and then connect to another
instance.
Notes:
•
•
If you do not specify the -force parameter, then sessions
already connected to this service stay connected, but new
sessions cannot be established to the service.
Optionally, you can specify the -noreplay parameter if you
do not want Application Continuity to replay in-flight
transactions after a session is terminated.
The -noreplay parameter is not limited to use with -force
but -force does require -noreplay if you do not want to
replay in-flight transactions after you force the service to
stop.
-global_override
Override value to operate on a global service. SRVCTL ignores
this parameter if the service is not a global service.
-verbose
Use this parameter to display verbose output.
Examples
The following example command stops services running on database db1:
$ srvctl stop service -db db1 -drain_timeout 60 -force - stopoption immediate verbose
srvctl stop vip
Stops a specific VIP or all VIPs on a specific node, including any VIPs that were
relocated due to a failover.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl stop vip command with the following syntax:
srvctl stop vip {-node node_name | -vip vip_name} [-force] [-relocate] [-verbose]
Table A-131
srvctl stop vip Parameters
Parameter
Description
-node node_name
This parameter stops all VIPs on a specific node, including
failed-over VIPs
A-140 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-131
(Cont.) srvctl stop vip Parameters
Parameter
Description
This parameter stops a specific VIP
-vip vip_name
Force SRVCTL to stop the VIP
-force
Relocate VIP
-relocate
Note: You must use the -nodenode_name parameter with the
-relocate parameter.
Verbose output
-verbose
Example
To stop all the VIPs on mynode1, including any failed-over VIPs, use the following
command:
$ srvctl stop vip -node mynode1 -verbose
srvctl stop volume
Stops a specific, running volume.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl stop volume command with the following syntax:
srvctl stop volume {-volume volume_name -diskgroup disk_group_name |
-device volume_device} [-node "node_list"]
Table A-132
srvctl stop volume Parameters
Parameter
-volume volume_name
-diskgroup disk_grp_name
-device volume_device
-node "node_list"
Description
Specify the name of the volume to stop.
Specify the name of the disk group in which the volume to
stop resides.
Specify the path to the volume device to stop.
Specify a comma-delimited list of node names where
volumes to stop reside.
Server Control Utility Reference A-141
SRVCTL Command Reference
Usage Notes
The srvctl stop volume command attempts to stop (disable) the volume but it
does not disable the resource or remove the volume from Oracle ASM.
Example
The following example stops a volume named VOLUME1 that resides in a disk group
named DATA:
$ srvctl stop volume -volume VOLUME1 -diskgroup DATA
unsetenv
The unsetenv command unsets values for the environment in the configuration file.
It allows users to administer environment configuration for the objects.
Table A-133
srvctl unsetenv Command Summary
Command
Description
srvctl unsetenv database
Unsets the value for one or more cluster database environment
variables
srvctl unsetenv listener
Unsets the value for one or more listener environment variables.
srvctl unsetenv
nodeapps
Unsets the value for one or more node application environment
variables
srvctl unsetenv vip
Unsets the value for one or more VIP environment variables
srvctl unsetenv database
Unsets the cluster database environment configurations.
Syntax and Parameters
Use the srvctl unsetenv database command as follows:
srvctl unsetenv database -db db_unique_name -envs "name_list"
Table A-134
srvctl unsetenv database Parameters
Parameter
-db db_unique_name
-envs "name_list"
Description
Unique name for the database
Comma-delimited list of environment variable names
enclosed in double quotation marks ("")
Example
The following example unsets the environment configuration for a cluster database
environment variable:
$ srvctl unsetenv database -db crm -envs "CLASSPATH,LANG"
A-142 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
srvctl unsetenv listener
Unsets the environment configuration for a listener.
Syntax and Parameters
Use the srvctl unsetenv listener command as follows:
srvctl unsetenv listener [-listener listener_name] -envs "name_list"
Table A-135
srvctl unsetenv listener Parameters
Parameter
Description
-listener listener_name
-envs "name_list"
Name of the listener.
If you do not specify this parameter, then the name of the
listener defaults to LISTENER.
A comma-delimited list of names of environment
variables
Example
The following example unsets the environment variable TNS_ADMIN for the default
listener:
$ srvctl unsetenv listener -envs "TNS_ADMIN"
srvctl unsetenv nodeapps
Unsets the environment configuration for the node applications.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl unsetenv nodeapps command as follows:
srvctl unsetenv nodeapps -envs "name_list" [-viponly] [-gsdonly]
[-onsonly] [-verbose]
Table A-136
srvctl unsetenv nodeapps Parameters
Parameter
Description
-envs "name_list"
Comma-delimited list of the names of environment
variables enclosed in double quotation marks ("")
-viponly
Modify only the VIP configuration instead of all
nodeapps
-gsdonly
Modify only the GSD configuration instead of all
nodeapps
Server Control Utility Reference A-143
SRVCTL Command Reference
Table A-136
(Cont.) srvctl unsetenv nodeapps Parameters
Parameter
Description
-onsonly
Modify only the ONS daemon configuration instead of all
nodeapps
Display verbose output
-verbose
Example
The following example unsets the environment configuration for all node applications:
$ srvctl unsetenv nodeapps -envs "test_var1,test_var2"
srvctl unsetenv vip
Unsets the environment configuration for the specified cluster VIP.
Syntax and Parameters
Use the srvctl unsetenv vip command as follows:
srvctl unsetenv vip -vip "vip_name_list" -envs "name_list" [-verbose]
Table A-137
srvctl unsetenv vip Parameters
Parameter
Description
-vip "vip_name_list"
Comma-delimited list of VIP names enclosed in double quotation
marks ("")
-envs "name_list"
Comma-delimited list of environment variable names enclosed in
double quotation marks ("")
Display verbose output
-verbose
Example
The following example unsets the CLASSPATH environment variable for a cluster VIP:
$ srvctl unsetenv vip -vip "crm2-vip" -envs "CLASSPATH"
update
The srvctl update command requests that the specified running object use the new
configuration information stored in the OCR.
Table A-138
srvctl update Command Summary
Command
Description
srvctl update database
Updates the specified database to use the new
listener endpoints
srvctl update gns
Updates the configuration for GNS
A-144 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-138
(Cont.) srvctl update Command Summary
Command
Description
srvctl update listener
Updates the listener to listen on the new
endpoints
srvctl update scan_listener
Update the SCAN listeners to listen on the new
endpoints.
srvctl update database
Updates the specified database to use the new listener endpoints.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl update database command with the following syntax:
srvctl update database -db db_unique_name
Use the -db parameter to specify the unique name of the database to update.
srvctl update gns
Use the srvctl update gns command to modify a Grid Naming Service (GNS)
instance.
Note:
This command is only available with Oracle Clusterware.
Syntax and Parameters
Use the srvctl update gns command with one of these syntax models:
srvctl update gns -advertise name -address ip_address [-timetolive time_to_live]
[-verbose]
srvctl update gns -delete name [-address address] [-verbose]
srvctl update gns -alias alias -name name [-timetolive time_to_live] [-verbose]
srvctl update gns -deletealias alias [-verbose]
srvctl update gns -createsrv service -target target -protocol protocol
[-weight weight] [-priority priority] [-port port_number]
[-timetolive time_to_live] [-instance instance_name] [-verbose]
srvctl update gns -deletesrv service_name -target target -protocol protocol
[-verbose]
srvctl update gns -createtxt name -target target [-timetolive time_to_live]
[-namettl name_ttl] [-verbose]
Server Control Utility Reference A-145
SRVCTL Command Reference
srvctl update gns -deletetxt name -target target [-verbose]
srvctl update gns -createptr name -target target [-timetolive time_to_live]
[-namettl name_ttl] [-verbose]
srvctl update gns -deleteptr name -target target [-verbose]
Table A-139
srvctl update gns Parameters
Parameter
-advertise name
-address ip_address
-timetolive time_to_live
-delete name
-alias alias
-name name
-deletalias alias
-createsrv service
-target target
-protocol protocol
-weight weight
Description
Advertise a name through GNS
The IP address for an advertised name
Optionally, you can specify, in seconds, an amount of time
for the record to live
Remove the advertisement of a name from GNS
Create an alias for an advertised name
The advertised name associated with the alias
Delete an alias
Create a service that is described by the record
Specify a name that is associated with the service
Specify which protocol is used to connect to the service
Specify the weight of the record
-priority priority
Specify the priority of the record, with a value ranging
from 0 to 65535
-port port_number
Specify the port number used to connect to the service,
with a value ranging from 0 to 65535
-instance instance_name
-deletesrv service
Instance name of service
Name of the service record to be deleted
A-146 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-139
(Cont.) srvctl update gns Parameters
Parameter
-createtxt name
-namettl name_ttl
-deletetxt name
-createptr name
-deleteptr name
Description
Add a text (TXT) record using the specified name
Time to live for the name, specified in seconds
Delete a text (TXT) record of the specified name
Add a pointer (PTR) record for the specified name
Delete a pointer (PTR) record for the specified name
Usage Notes
You must be logged in as the root user on Linux and UNIX platforms, or as an
Administrator user on Windows platforms, to run this command.
Example
The following command advertises a name with GNS:
# srvctl update gns -advertise myname -address 192.168.1.45
srvctl update instance
The srvctl update instance command changes to which Oracle ASM instance
or Oracle ASM IOServer the instance connects, or it changes the open mode of the
instance.
Syntax
srvctl update instance -db db_unique_name [-instance "instance_name_list"
| -node "node_list"] [-startoption start_options] [-targetinstance instance_name]
Parameters
Parameter
Description
-db db_unique_name
Specify the unique name of the database.
-instance
"instance_name_lis
t" | -node
"node_list"
Optionally, you can specify a comma-delimited list of instance
names or node names that you want to update. If you specify a list
of node names, then SRVCTL udpates the instances running on
those specific nodes.
-startoption
start_options
Optionally, you can specify startup options for the database, such
as OPEN, MOUNT, or "READ ONLY".
Server Control Utility Reference A-147
SRVCTL Command Reference
Parameter
Description
-targetinstance
instance_name
Optionally, you can specify a target Oracle ASM or Oracle ASM
IOServer instance. Use double quotation marks ("") to specify the
default target instance)
Examples
An example of this command is:
$ srvctl update instance -db qdb -node rws1270051 -targetinstance +IOS2
relocate qdb instance on rws1270050 to IOServer instance +IOS2
srvctl update listener
Updates the listener to listen on the new endpoints.
Note:
This command is only available with Oracle Clusterware.
Use the srvctl update listener command with the following syntax:
srvctl update listener
This command does not accept any additional parameters, except for -help.
srvctl update scan_listener
Updates the SCAN listeners to listen on the new endpoints.
Note:
This command is only available with Oracle Clusterware.
Use the srvctl update scan_listener command with the following syntax:
srvctl update scan_listener
This command does not accept any additional parameters, except for -help.
srvctl upgrade database
The srvctl upgrade database command upgrades the configuration of a
database and all of its services to the version of the database home from where this
command is run.
Syntax and Parameters
Use the srvctl upgrade database command as follows:
srvctl upgrade database -db db_unique_name -oraclehome Oracle_home
A-148 Oracle Real Application Clusters Administration and Deployment Guide
SRVCTL Command Reference
Table A-140
srvctl upgrade database Parameters
Parameter
-db db_unique_name
-oraclehome Oracle_home
Description
Unique name for the database
The path to the ORACLE_HOME
Server Control Utility Reference A-149
SRVCTL Command Reference
A-150 Administration and Deployment Guide
B
Troubleshooting Oracle RAC
This appendix explains how diagnose problems for Oracle Real Application Clusters
(Oracle RAC) components using trace and log files. This section includes the following
topics:
•
Where to Find Files for Analyzing Errors
•
Managing Diagnostic Data in Oracle RAC
•
Using Instance-Specific Alert Files in Oracle RAC
•
Enabling Tracing for Java-Based Tools and Utilities in Oracle RAC
•
Resolving Pending Shutdown Issues
•
How to Determine If Oracle RAC Instances Are Using the Private Network
•
Database Fails to Start after Private NIC Failure
Note:
Trace and log files, similar to those generated for Oracle Database with Oracle
RAC, are also available for the Oracle Clusterware components. For Oracle
Clusterware, Oracle Database stores these under a unified directory log
structure.
See the Oracle Clusterware Administration and Deployment Guide for more
information about troubleshooting Oracle Clusterware.
Where to Find Files for Analyzing Errors
Oracle Database records information about important events that occur in your Oracle
RAC environment in trace files. The trace files for Oracle RAC are the same as those in
noncluster Oracle databases. As a best practice, monitor and back up trace files
regularly for all instances to preserve their content for future troubleshooting.
Information about ORA-600 errors appear in the alert_SID.log file for each
instance where SID is the instance identifier.
The alert log and all trace files for background and server processes are written to the
Automatic Diagnostic Repository, the location of which you can specify with the
DIAGNOSTIC_DEST initialization parameter. For example:
diagnostic_dest=/oracle/11.1/diag/rdbms/rac/RAC2/trace
Oracle Database creates a different trace file for each background thread. Oracle RAC
background threads use trace files to record database operations and database errors.
These trace logs help troubleshoot and also enable Oracle Support to more efficiently
Troubleshooting Oracle RAC B-1
Managing Diagnostic Data in Oracle RAC
debug cluster database configuration problems. The names of trace files are operating
system specific, but each file usually includes the name of the process writing the file
(such as LGWR and RECO). For Linux, UNIX, and Windows systems, trace files for
the background processes are named SID_process name_process
identifier.trc.
See Also:
Oracle Database Administrator's Guide and Oracle Database 2 Day + Real
Application Clusters Guide for more information about monitoring errors and
alerts in trace files
Trace files are also created for user processes if you set the DIAGNOSTIC_DEST
initialization parameter. User process trace file names have the format
SID_ora_process_identifier/thread_identifier.trc, where
process_identifier is a 5-digit number indicating the process identifier (PID) on
Linux and UNIX systems, and thread_identifier is the thread identifier on
Windows systems.
Managing Diagnostic Data in Oracle RAC
Problems that span Oracle RAC instances can be the most difficult types of problems
to diagnose.
For example, you may need to correlate the trace files from across multiple instances,
and merge the trace files. Oracle Database 12c release 2 (12.2) includes an advanced
fault diagnosability infrastructure for collecting and managing diagnostic data, and
uses the Automatic Diagnostic Repository (ADR) file-based repository for storing the
database diagnostic data. When you create the ADR base on a shared disk, you can
place ADR homes for all instances of the same Oracle RAC database under the same
ADR Base. With shared storage:
•
You can use the ADRCI command-line tool to correlate diagnostics across all
instances.
ADRCI is a command-line tool that enables you to view diagnostic data in the
ADR and package incident and problem information into a zip file for
transmission to Oracle Support. The diagnostic data includes incident and
problem descriptions, trace files, dumps, health monitor reports, alert log entries,
and so on.
See Also:
Oracle Database Utilities for information about using ADRCI
•
You can use the Data Recovery Advisor to help diagnose and repair corrupted
data blocks, corrupted or missing files, and other data failures.
The Data Recovery Advisor is an Oracle Database infrastructure that
automatically diagnoses persistent data failures, presents repair options, and
repairs problems at your request.
B-2 Oracle Real Application Clusters Administration and Deployment Guide
Using Instance-Specific Alert Files in Oracle RAC
See Also:
Oracle Database Administrator’s Guide for information about managing
diagnostic data
Using Instance-Specific Alert Files in Oracle RAC
Each instance in an Oracle RAC database has one alert file. The alert file for each
instance, alert.SID.log, contains important information about error messages and
exceptions that occur during database operations. Information is appended to the alert
file each time you start the instance. All process threads can write to the alert file for
the instance.
The alert_SID.log file is in the directory specified by the DIAGNOSTIC_DEST
initialization parameter.
Enabling Tracing for Java-Based Tools and Utilities in Oracle RAC
All Java-based tools and utilities that are available in Oracle RAC are called by
executing scripts of the same name as the tool or utility.
This includes the Cluster Verification Utility (CVU), Database Configuration Assistant
(DBCA), the Net Configuration Assistant (NETCA), Server Control Utility (SRVCTL),
and the Global Services Daemon (GSD). For example, to run DBCA, enter the
command dbca.
By default, Oracle Database enables traces for DBCA and the Database Upgrade
Assistant (DBUA). For the CVU, GSDCTL, and SRVCTL, you can set the SRVM_TRACE
environment variable to TRUE to make Oracle Database generate traces. Oracle
Database writes traces to log files. For example, Oracle Database writes traces to log
files in Oracle_base/cfgtoollogs/dbca and Oracle_base/cfgtoollogs/
dbua for DBCA and DBUA, respectively.
Resolving Pending Shutdown Issues
In some situations a SHUTDOWN IMMEDIATE may be pending and Oracle Database
will not quickly respond to repeated shutdown requests. This is because Oracle
Clusterware may be processing a current shutdown request. In such cases, issue a
SHUTDOWN ABORT using SQL*Plus for subsequent shutdown requests.
How to Determine If Oracle RAC Instances Are Using the Private Network
This section describes how to manually determine if Oracle RAC instances are using
the private network. However, the best practice for this task is to use the Oracle
Enterprise Manager Cloud Control graphical user interface (GUI) to check the
interconnect. Also, see the Oracle Database 2 Day + Real Application Clusters Guide for
more information about monitoring Oracle RAC using Oracle Enterprise Manager.
With most network protocols, you can issue the oradebug ipc command to see the
interconnects that the database is using. For example:
oradebug setmypid
oradebug ipc
These commands dump a trace file to the location specified by the
DIAGNOSTIC_DEST initialization parameter. The output may look similar to the
following:
Troubleshooting Oracle RAC B-3
Database Fails to Start after Private NIC Failure
SSKGXPT 0x1a2932c flags SSKGXPT_READPENDING
info for network 0
socket no 10
IP 172.16.193.1
UDP 43749
sflags SSKGXPT_WRITESSKGXPT_UP info for network 1
socket no 0
IP 0.0.0.0
UDP 0...
In the example, you can see the database is using IP 172.16.193.1 with a User Datagram
Protocol (UDP) protocol. Also, you can issue the oradebug tracefile_name
command to print the trace location where the output is written.
Additionally, you can query the V$CLUSTER_INTERCONNECTS view to see
information about the private interconnect. For example:
SQL> SELECT * FROM V$CLUSTER_INTERCONNECTS;
NAME
----eth0
IP_ADDRESS
IS_
SOURCE
-------------------------- --------------------------------138.2.236.114
NO
Oracle Cluster Repository
Database Fails to Start after Private NIC Failure
In a two-node cluster that is not using grid interprocess communication (GIPC) and
has only a single private network interface card (NIC), when the NIC fails on the node
on which the Oracle Grid Infrastructure Management Repository database (mgmtdb)
is running (node A, for example) after the other node (node B) was evicted, then when
the private network is reestablished on node A, node B joins the cluster but the
database instance on node A is unable to start.
To start the database instance:
1.
Stop the Oracle Clusterware stack on both nodes, as follows:
crsctl stop cluster
2.
Start the Oracle Clusterware stack on both nodes, as follows:
crsctl start cluster
3.
Stop the database instance on node A, on which the NIC failed, as follows:
srvctl stop instance -db db_unique_name -node A
4.
Start the database on both nodes by running the following commands one of the
nodes:
srvctl start instance -db db_unique_name -node B
srvctl start instance -db db_unique_name -node A
The database instance will fail to start on node A until after the instance starts on
node B.
B-4 Oracle Real Application Clusters Administration and Deployment Guide
Glossary
Automatic Workload Repository (AWR)
A built-in repository that exists in every Oracle database. At regular intervals, Oracle
Database makes a snapshot of all of its vital statistics and workload information and
stores them in the AWR.
administrator-managed database
A database that you specifically define on which servers it can run, and where services
can run within the database.
cache coherency
The synchronization of data in multiple caches so that reading a memory location
through any cache will return the most recent data written to that location through
any other cache. Sometimes called cache consistency.
Cache Fusion
A diskless cache coherency mechanism in Oracle RAC that provides copies of blocks
directly from a holding instance's memory cache to a requesting instance's memory
cache.
cardinality
The number of database instances you want running during normal operations.
CDB
A multitenant container database (CDB) is an Oracle database that includes zero, one,
or many user-created pluggable databases (PDBs). Every Oracle database is either a
CDB or a non-CDB.
client cluster
A cluster that advertises its names with the server cluster.
cluster
Multiple interconnected computers or servers that appear as if they are one server to
end users and applications.
Glossary-1
cluster configuration policy
cluster configuration policy
A document that contains exactly one definition for each server pool defined in the
system.
cluster configuration policy set
A document that defines the names of all server pools configured in the cluster and
contains one or more configuration policies.
cluster database
The generic term for a Oracle RAC database.
cluster file system
A distributed file system that is a cluster of servers that collaborate to provide high
performance service to their clients. Cluster file system software deals with
distributing requests to storage cluster components.
Cluster Ready Services Daemon (CRSD)
The primary Oracle Clusterware process that performs high availability recovery and
management operations, such as maintaining OCR. Also manages application
resources and runs as root user (or by a user in the admin group on Mac OS X-based
systems) and restarts automatically upon failure.
Cluster Synchronization Services (CSS)
An Oracle Clusterware component that discovers and tracks the membership state of
each node by providing a common view of membership across the cluster. CSS also
monitors process health, specifically the health of the database instance. The Global
Enqueue Service Monitor (LMON), a background process that monitors the health of
the cluster database environment and registers and de-registers from CSS. See also,
OCSSD.
Cluster Time Synchronization Service
A time synchronization mechanism that ensures that all internal clocks of all nodes in
a cluster are synchronized.
Cluster Verification Utility (CVU)
A tool that verifies a wide range of Oracle RAC components such as shared storage
devices, networking configurations, system requirements, Oracle Clusterware, groups,
and users.
commit outcome
A message sent to the client from the Oracle database after a transaction has been
committed. These messages are not durable.
Glossary-2
Fast Connection Failover
database pool
A set of databases within a database cloud that provide a unique set of global services
and belong to a certain administrative domain. Partitioning of cloud databases into
multiple pools simplifies service management and provides higher security because
each pool can be administered by a different administrator.
Distributed Transaction Processing (DTP)
The paradigm of distributed transactions, including both XA-type externally
coordinated transactions, and distributed-SQL-type (database links in Oracle)
internally coordinated transactions.
dynamic network
A network that uses DHCP for IPv4 or stateless autoconfiguration (autoconfig) for
IPv6.
Event Manager (EVM)
The background process that publishes Oracle Clusterware events. EVM scans the
designated callout directory and runs all scripts in that directory when an event
occurs.
Event Manager Daemon (EVMD)
A Linux or UNIX event manager daemon that starts the racgevt process to manage
callouts.
failur