Oracle Net Services 12c Release 2 (12.2) Networking Software Administrator's Guide
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Oracle
®
Database
Net Services Administrator's Guide
12c Release 2 (12.2)
E49642-09
July 2017
Oracle Database Net Services Administrator's Guide, 12c Release 2 (12.2)
E49642-09
Copyright
©
2002, 2017, Oracle and/or its affiliates. All rights reserved.
Primary Author: Reema Khosla
Contributors: Robert Achacoso, Matt Cassady, Abhishek Dadhich, Santanu Datta, Steve Ding, Feroz Khan,
Bhaskar Mathur, Scot McKinley, Ed Miner, Sweta Mogra, Srinivas Pamu, Kant Patel, Murali Purayathu,
Karthik Rajan, Saravanakumar Ramasubramanian, Kevin Reardon, Sudeep Reguna, James Spiller, Norman
Woo
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Contents
Preface
Changes in This Release for Oracle Database Net Services Administrator's Guide
Part I Understanding Oracle Net Services
1 Introducing Oracle Net Services
2 Identifying and Accessing the Database
iii
3 Managing Network Address Information
3.2.7 Limitations of Directory Naming Support with Microsoft Active Directory.............
4 Understanding the Communication Layers
4.1 Understanding Oracle Net Stack Communication for Client/Server Applications...............
iv
5 Understanding Oracle Net Architecture
Part II Configuration and Administration of Oracle Net Services
6 Quick Start to Oracle Net Services
7 Managing Oracle Net Services
7.1.1 Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net Services .
7.1.3 Deciding When to Use Oracle Enterprise Manager Cloud Control and Oracle Net
7.1.4 Using Oracle Net Configuration Assistant to Configure Network Components........
8 Configuring Naming Methods
v
9 Configuring and Administering Oracle Net Listener
9.4.2 Handling Large Volumes of Concurrent Connection Requests ...................................
10 Configuring Oracle Connection Manager
10.2.1 Configuring the cman.ora file for the Oracle Connection Manager Host.................
10.2.3 Configuring the Oracle Database Server for Oracle Connection Manager...............
10.4 Using the Oracle Connection Manager Control Utility to Administer Oracle Connection
11 Configuring a Shared Server Architecture
vi
11.3 Configuring Clients for Environments with Both Shared and Dedicated Servers .............
12 Configuring Profiles
12.5.1 Setting the Advanced Features in the sqlnet.ora File Using Oracle Net Services....
13 Enabling Advanced Features of Oracle Net Services
13.1 Configuring Advanced Network Address and Connect Data Information ........................
13.2.1 Example of Connection Load Balancing for Shared Server Configuration ..............
13.2.2 Example of Connection Load Balancing for Dedicated Server Configuration ......
13.4 Specifying the Instance Role for Primary and Secondary Instance Configurations .........
13.6.2 About Oracle Net Services for Oracle Heterogeneous Services ...............................
13.6.3 Configuring Oracle Net Services for an Oracle Rdb Database .................................
14 Optimizing Performance
vii
14.8.1 Configuring Data-Dependent Routing for Client-Server Connections...................
Part III Testing and Troubleshooting Oracle Net Services
15 Testing Connections
16 Troubleshooting Oracle Net Services
16.3 Resolving the Most Common Error Messages for Oracle Net Services..............................
16.3.2 ORA-12154: Could Not Resolve the Connect Identifier Specified ...........................
16.3.4 TNS-12500 or ORA-12500: Listener Failed to Start a Dedicated Server Process....
16.3.5 ORA-12514: Listener Does Not Currently Know of Service Requested in Connect
16.3.6 ORA-12520: Listener Could Not Find Available Handler for Requested Type of
16.3.7 ORA-12521: Listener Does Not Currently Know of Instance Requested in Connect
16.3.8 ORA-12525: Listener Has Not Received Client's Request in Time Allowed ..........
viii
16.3.10 TNS-12540 or ORA-12540: TNS:Internal Limit Restriction Exceeded and
16.3.12 TNS-12549 or ORA-12549: TNS:Operating System Resource Quota Exceeded and
TNS-00519: Operating System Resource Quota Exceeded ..............................................
16.3.13 TNS-12560 or ORA-12560: TNS:Protocol Adapter Error Occurred .......................
16.4.1 Questions to Consider When Troubleshooting Oracle Net Services.......................
Glossary
Index
ix
x
List of Tables
Naming Methods: Advantages and Disadvantages............................................................
2-14
Oracle Net Configuration Files Used with Localized Management....................................
3-1
ACL Requirements for User Groups......................................................................................
3-13
Oracle Net Services LDAP Main Object Classes...................................................................
3-15
Oracle Net Services LDAP Derived Object Classes..............................................................
3-15
Supported Host and Network Configurations.....................................................................
4-11
Connecting to a Database...........................................................................................................
6-5
Connect Identifier for Easy Connection Naming Method.....................................................
8-2
Examples of Easy Connect Naming..........................................................................................
8-4
Listener Control Utility STATUS Command........................................................................
9-17
Listener Control Utility SERVICES Command.....................................................................
9-19
Rule-Level Parameters in cman.ora File................................................................................
10-3
Session Multiplexing Parameters............................................................................................
10-8
Naming Method Values...........................................................................................................
12-3
Access Control Settings in sqlnet.ora.....................................................................................
12-5
Advanced Settings in sqlnet.ora..............................................................................................
12-6
Address List Parameters in the tnsnames.ora File...............................................................
13-4
Address List Options Dialog Box............................................................................................
13-4
Advanced Connect Data Settings in the tnsnames.ora File................................................
13-6
Additional Parameters of the FAILOVER_MODE Parameter.........................................
13-15
INSTANCE_ROLE Parameters.............................................................................................
13-19
Static Service Settings in listener.ora....................................................................................
13-22
External Procedures Settings in listener.ora........................................................................
13-25
Oracle RDB Database Settings in a Connect Descriptor....................................................
13-31
Connect-Timeout Parameters................................................................................................
14-10
ADR Home Path Components for an Oracle Net Listener Instance..................................
16-2
ADR Home Path Components for an Oracle Connection Manager Instance..................
16-2
ADR Home Subdirectories.......................................................................................................
16-3
sqlnet.ora File Diagnostic Parameter Comparison...............................................................
16-4
listener.ora File Diagnostic Parameter Comparison.............................................................
16-4
cman.ora File Diagnostic Parameter Comparison................................................................
16-5
....................................................................................................................................................
16-10
ldifwrite Arguments...............................................................................................................
16-20
Error Stack Components........................................................................................................
16-22
Log File Names When Using ADR.......................................................................................
16-24
Location of Log Parameters...................................................................................................
16-24
sqlnet.ora Log Parameters.....................................................................................................
16-25
listener.ora Log Parameters...................................................................................................
16-26
cman.ora Log Parameters......................................................................................................
16-26
Service Registration Event Log Information.......................................................................
16-31
CMADMIN and Gateway Log Entries.................................................................................
16-35
Trace Files Names...................................................................................................................
16-37
Location of Trace Parameters................................................................................................
16-37
cman.ora Trace Parameters....................................................................................................
16-38
listener.ora Trace Parameters................................................................................................
16-39
sqlnet.ora Trace Parameters...................................................................................................
16-40
TNSPING Trace Parameters..................................................................................................
16-44
Trace Assistant Syntax............................................................................................................
16-51
xi
xii
Preface
Oracle Database Net Services Administrator's Guide
describes how to use Oracle Net
Services. This guide describes the Oracle Net Services product and its components, as well as Oracle Net Services administrative and deployment topics. This preface contains the following topics:
•
•
Documentation Accessibility (page xiv)
•
(page xiv)
•
(page xv)
Audience
Oracle Database Net Services Administrator's Guide
is intended for the following readers:
• Network administrators
• Directory server administrators
• Database administrators
• Decision makers
This guide is especially targeted for network administrators who are responsible for ensuring connectivity. For network administrators, Oracle recommends:
• For a conceptual understanding of Oracle Net Services, read all of
(page 1)
• For essential configuration instructions, read all of
Administration of Oracle Net Services
(page 1)
• For troubleshooting, read
Testing and Troubleshooting Oracle Net Services
(page 1)
For directory administrators, Oracle recommends:
• For understanding how Oracle Net Services uses a directory server, read
Managing Network Address Information (page 3-1) in
• For instructions about configuring naming information in a directory server, and exporting existing naming data to a directory server, read
xiii
Configuration and Administration of Oracle Net Services
(page 1)
For database administrators, Oracle recommends:
•
For a general understanding of networking, read Introducing Oracle Net Services
(page 1-1) and
Quick Start to Oracle Net Services (page 6-1)
•
For an overview of communication layers, read Understanding the
Communication Layers (page 4-1)
• For understanding how to configure Oracle database server features that require
listener and shared server configuration, read Configuring and Administering
(page 9-1), Configuring a Shared Server Architecture
(page 11-1), and
Optimizing Performance (page 14-1)
For decision makers, Oracle recommends
• For an understanding of how Oracle Net Services fits into the overall network
architecture and for explaining the basics of Oracle Net Services, read Introducing
(page 1-1), Managing Network Address Information
(page 3-1), and Quick Start to Oracle Net Services
(page 6-1)
Oracle recommends that all readers look over
Understanding Oracle Net Services
(page 1), to ensure that they have the background required to benefit from the rest of the guide.
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.
Related Documentation
For additional information, see the following Oracle resources:
•
Oracle Database Net Services Reference
• Oracle Database 12c Release 2 (12.2) documentation set
•
Oracle Database Global Data Services Concepts and Administration Guide
Many books in the documentation set use the sample schemas of the seed database, which is installed by default when you install Oracle Database. Refer to Oracle
Database Sample Schemas
for information about how these schemas were created and how you can use them yourself. Oracle error message documentation is only available in HTML.
To download free release notes, installation documentation, white papers, or other collateral, visit the Oracle Technology Network. You must register online before using
Oracle Technology Network; registration is free and can be done at
xiv
http://www.oracle.com/technetwork/index.html
If you already have a user name and password for Oracle Technology Network, then you can go directly to the documentation section of the Oracle Technology Network website at http://docs.oracle.com/
http://www.ietf.org
Conventions
The examples for directories in the book are for Linux. Unless otherwise noted,
Microsoft Windows directory paths are the same except that they use a backslash (\) instead of the forward slash (/).
The following text conventions are used in this document:
Convention boldface
italic
monospace
Meaning
Boldface type indicates graphical user interface elements associated with an action, or terms defined in text or the glossary.
Italic type indicates book titles, emphasis, or placeholder variables for which you supply particular values.
Monospace type indicates commands within a paragraph, URLs, code in examples, text that appears on the screen, text that you enter, file names and directory names.
xv
Changes in This Release for Oracle
Database Net Services Administrator's
Guide
This preface describes the new networking features of Oracle Database 12c and provides pointers to additional information.
Changes in Oracle Net Services 12c Release 2 (12.2)
The following are the changes in Oracle Database Net Services Administrator's Guide for
Oracle Database 12c Release 2 (12.2):
New Features
The following are the new features in Oracle Net Services:
• Listener Parameter for Multiple Redirects
Starting with Oracle Database 12c release 2 (12.2), Oracle Net listener supports multiple redirects with the introduction of a new listener parameter,
ALLOW_MULTIPLE_REDIRECTS_listener_name
. It supports seamless migration of a PDB from a local database to the Oracle Public Cloud.
See Also:
–
Understanding Listener Redirects (page 9-20)
– ALLOW_MULTIPLE_REDIRECTS_listener_name in Oracle Database Net
Services Reference
• Sharding and Data Dependent Routing
This feature provides the ability to horizontally partition the data across multiple independent Oracle databases, also called shards, and based on a key specified in the connect string, route the database requests to a particular shard.
xvii
xviii
See Also:
– CONNECT_DATA section in Oracle Database Net Services Reference for information about the new parameters
–
(page 14-11)
–
Oracle Data Provider for .NET Developer's Guide for Microsoft Windows
for more information about this feature
• SCAN Listener Support for HTTP
This feature enables load balancing across the HTTP presentation handlers residing on different nodes by redirecting to the least loaded node.
• ExaDirect SQL*Net Adapter
Use the ExaDirect SQL*Net adapter for low overhead database access. Use the new transport to improve latency and throughput by leveraging Remote Direct
Memory Access (RDMA) in an InfiniBand environment.
• Direct SQL*Net Access Over Oracle Cloud
This feature enables Oracle Cloud support for Oracle Database over SQL*Net. The existing applications can use Oracle Cloud without any code changes.
It allows the database clients to securely access the database public cloud service without opening an extra outbound port.
• Service-Level ACLs for TCP Protocol
This feature allows every database service to have its own access control list
(ACL) and the ACL is based on IPs. Since each pluggable database is a different service, this feature enables different pluggable databases to have different ACLs.
These ACLs are enforced by the listener. In other words, access to a pluggable database service is enabled only for IPs that are permitted through an ACL.
Part I
Understanding Oracle Net Services
Part I provides an overview of Oracle Net Services concepts, products, and tools.
This part contains the following chapters:
•
Introducing Oracle Net Services
(page 1-1)
•
Identifying and Accessing the Database
(page 2-1)
•
Managing Network Address Information (page 3-1)
•
Understanding the Communication Layers (page 4-1)
•
Understanding Oracle Net Architecture (page 5-1)
1
Introducing Oracle Net Services
Understand the basic elements of Oracle Net Services architecture and the Oracle Net foundation layer.
•
(page 1-1)
•
Components of Oracle Net Services
(page 1-15)
1.1 About Oracle Net Services
provides enterprise-wide connectivity solutions in distributed, heterogeneous computing environments. Oracle Net Services eases the complexities of network configuration and management, maximizes performance, and improves network diagnostic capabilities.
Note:
The terms "SQL*Net" and "Net Services" are used interchangeably throughout Oracle documentation and both these terms refer to the same functionality.
This section introduces the basic networking concepts involved in a typical network configuration. This section contains the following topics:
•
Understanding Connectivity (page 1-1)
•
Understanding Manageability (page 1-5)
•
Understanding Shared Server Architecture (page 1-7)
•
Understanding Performance (page 1-9)
•
Understanding Network Security (page 1-12)
1.1.1 Understanding Connectivity
, a component of Oracle Net Services, enables a network session from a
client application to an Oracle Database server. When a network session is established,
Oracle Net acts as the data courier for both the client application and the database. It is responsible for establishing and maintaining the connection between the client application and database, as well as exchanging messages between them. Oracle Net is able to perform these jobs because it is located on each computer in the network.
This section contains the following topics:
•
About Client/Server Application Connections (page 1-2)
•
About Web Client Application Connections
(page 1-3)
Introducing Oracle Net Services 1-1
About Oracle Net Services
1.1.1.1 About Client/Server Application Connections
Oracle Net enables connections from traditional client/server applications to Oracle
Database servers.
(page 1-2) shows how Oracle Net enables a network connection between a client and a database server. Oracle Net is a software component that resides on both the client and the database server. Oracle Net is layered on top of network
, rules that determine how applications access the network and how data is subdivided into packets for transmission across the network.
In
(page 1-2), Oracle Net communicates with
to enable computerlevel connectivity and data transfer between the client and the database.
Figure 1-1 Client/Server Application Connection
Database
Server
Client
Application
Oracle
Net
TCP/IP
Network
RDBMS
Oracle
Net
Specifically, Oracle Net is comprised of the
establishes and maintains connections, and
foundation layer technology to industry-standard protocols.
1.1.1.1.1 Java Client Application Connections
Java client applications access an Oracle database through a
, a standard Java interface for connecting from Java to a
relational database. Oracle offers the following drivers:
•
for client-side use with an Oracle client installation.
•
, a pure Java driver for client-side use without an Oracle
installation, particularly with applets.
These drivers use Oracle Net to enable connectivity between a client application and an Oracle database.
Figure 1-2 (page 1-2) shows a Java client application using a JDBC OCI driver and
an Oracle Database server. The Java client application makes calls to the JDBC OCI driver, which translates the JDBC calls directly into the Oracle Net layer. The client then uses Oracle Net to communicate with Oracle Database that is also configured with Oracle Net.
Figure 1-2 Java Application Connection
Database
Server
Client
Application
JDBC OCI
Driver
Oracle
Net
TCP/IP
Network
RDBMS
Oracle
Net
1-2 Oracle Database Net Services Administrator's Guide
About Oracle Net Services
See Also:
•
Oracle Database JDBC Developer's Guide
•
Oracle Database JDBC Java API Reference
1.1.1.2 About Web Client Application Connections
Internet connections from client web browsers to an Oracle Database server are similar to client/server applications, except that the connection request goes to an application web server.
Figure 1-3 (page 1-3) shows the basic architecture for web client connections,
including a client web browser, an application web server, and an Oracle Database server. The browser on the client communicates with
to the web server to make a connection request. The web server sends the request to an application where it is processed. The application then uses Oracle Net to communicate with the Oracle
Database server that also is configured with Oracle Net.
Figure 1-3 Web Client Connections through Application Web Server
Application
Web Server
Database
Server
Client
Web
Browser
TCP/IP
Network
HTTP
Protocol
Oracle
Net
TCP/IP
Network
RDBMS
Oracle
Net
The basic components have the following characteristics:
• HyperText Transport Protocol (HTTP)
HTTP provides the language that enables web browsers and application web servers to communicate.
• Application Web Server
An application web server manages data for a website, controls access to that data, and responds to requests from web browsers. The application on the web server communicates with the database and performs the job requested by the web server.
1.1.1.2.1 Web Client Connections Through Java Application Web Server
An application web server can host Java applications and servlets, as shown in
Figure 1-4 (page 1-4). Web browsers make a connection request by communicating
through HTTP to an application web server. The application web server sends the request to an application or a servlet, which uses a JDBC OCI or a JDBC Thin driver to process the request. The driver then uses Oracle Net to communicate with the Oracle
Database server that also is configured with Oracle Net.
Introducing Oracle Net Services 1-3
About Oracle Net Services
Figure 1-4 Web Client Connections Through Java Application Web Server
Application
Web Server
Client
Web
Browser
HTTP
Protocol
JDBC OCI
Driver
Oracle Net
TCP/IP
Network
Database
Server
RDBMS
Oracle Net
Client
Web
Browser
Java Servlet
Driver
JavaNet
TCP/IP
Network
HTTP
Protocol
1.1.1.2.2 Web Client Connections Without an Application Web Server
Web clients that do not require an application web server to access applications can access Oracle Database directly, for example, by using a Java applet. In addition to
regular connections, the database can be configured to accept HTTP protocol,
connections. These protocols are used for connections to
in the Oracle Database instance.
Figure 1-5 (page 1-5) shows two different web clients. The first web client makes an
HTTP connection to the database. The second web client uses a web browser with a
JDBC Thin driver, which in turn uses a Java version of Oracle Net called JavaNet to communicate with the Oracle Database server that is configured with Oracle Net.
See Also:
Oracle XML DB Developer's Guide
1-4 Oracle Database Net Services Administrator's Guide
About Oracle Net Services
Figure 1-5 Web Client Connection Scenarios
Client
Web
Browser
HTTP
Protocol
Database
Server
Client
Web
Browser
RDBMS
Oracle
Net
Java Applet
JDBC Thin
Driver
JavaNet
TCP/IP
Network
Configured to support
HTTP
1.1.2 Understanding Manageability
Oracle Net Services offers several manageability features to configure and manage networking components. These features are described in the following topics:
•
(page 1-5)
•
About Centralized Configuration and Management
(page 1-6)
•
About Quick Installation and Configuration
(page 1-7)
1.1.2.1 About Location Transparency
Each database is represented by one or more services. A
is identified by a
sales.us.example.com
. A client uses a service name to identify the database it must access. The information about the database service and its location in the network is transparent to the client because the information needed for a connection is stored in a repository.
The repository is represented by one or more
s. A naming method is a resolution method used by a client application to resolve a connect identifier to a connect descriptor when attempting to connect to a database service. Oracle Net
Services offers several naming methods that support localized configuration on each client, or centralized configuration that can be accessed by all clients in the network.
For example, in
Figure 1-6 (page 1-6), a company has three databases that clients can
access. Each database has a distinct service name, such as sales.us.example.com
, hr.us.example.com
, and mktg.us.example.com
.
1.
2.
The client uses the repository to find the information it needs for sales.us.example.com
.
After the client has the information it needs, it connects to the database.
Introducing Oracle Net Services 1-5
About Oracle Net Services
Figure 1-6 Service Information Repository
1
Repository of service information sales = hr = mktg =
Client
2 sales.us.example.com
hr.us.example.com
mktg.us.example.com
1.1.2.2 About Centralized Configuration and Management
To manage large networking environments, administrators have to be able to easily access a centralized repository to specify and modify the network configuration. For this reason, the Oracle Net Services configuration can be stored in a LDAP-compliant directory server.
Support of LDAP-compliant directory servers provides a centralized vehicle for managing and configuring a distributed Oracle network. The directory can act as a central repository for all information about database network components, user and corporate policies, and user authentication and security, thus replacing client-side and server-side localized configuration files.
All computers on the network can refer to the directory for information. Figure 1-7
(page 1-6) shows clients, Oracle Database servers, and other servers (such as application web servers) connecting to a centralized directory server.
Figure 1-7 Centralized Storage of Network Configuration with a Directory Server
Directory
Server
Application
Web Server
Client
Client
Intranet
Database
Database
1-6 Oracle Database Net Services Administrator's Guide
About Oracle Net Services
See Also:
"
Using a Directory Server for Centralized Management (page 3-2)" for an in-
depth overview of directory server concepts
1.1.2.3 About Quick Installation and Configuration
Networking elements for the Oracle Database server and clients are preconfigured for most environments. The Easy Connect naming method is enabled by default, and does not require a repository. Clients connect using the hostname of the database. As a result, clients and servers are ready to connect out-of-the-box using Easy Connect, giving users the benefits of distributed computing.
1.1.3 Understanding Shared Server Architecture
The Oracle Database
architecture increases the scalability of applications
and the number of clients that can simultaneously be connected to the database. The shared server architecture also enables existing applications to scale up without making any changes to the application itself.
When using a shared server, clients do not communicate directly with a database
, a database process that handles a client's requests on behalf of a database. Instead, client requests are routed to one or more
s. The
dispatchers place the client requests in a common queue. An idle
the shared pool of server processes picks up and processes a request from the queue.
This means a small pool of server processes can serve a large number of clients.
(page 1-8) show the basic difference between
the shared server connection model and the traditional
connection model. In the shared server model, a dispatcher can support multiple client connections concurrently. In the dedicated server model, there is one server process for each client. Each time a connection request is received, a server process is started and dedicated to that connection until completed. This causes a processing delay.
Figure 1-8 Shared Server Architecture
Client
Web
Browser
Shared
Server
Process
Dispatcher
Client
Web
Browser
Database
Client
Web
Browser
Shared
Server
Process
Introducing Oracle Net Services 1-7
About Oracle Net Services
Figure 1-9 Dedicated Server Architecture
Client
Dedicated
Server
Process
Client
Dedicated
Server
Process
Database
Client
Dedicated
Server
Process
A shared server is ideal for configurations with a large number of connections because it reduces the server memory requirements. A shared server is well suited for both
Internet and intranet environments.
Utilization of server resources can be further enhanced with Oracle Connection
Manager.
, an Oracle Net Services component, enables multiple client network sessions to be multiplexed, or funneled, through a single network connection to a database.
The
feature reduces the demand on resources needed to
maintain multiple network sessions between two processes by enabling the server to use fewer network connection endpoints for incoming requests. In this way, the total number of network sessions that a server can handle is increased. One Oracle
Connection Manager with multiple gateways enables thousands of concurrent users to connect to a server.
(page 1-9) shows how session multiplexing can be used in a web architecture. When Oracle Connection Manager is run on the same computer as an application web server, the application web server can route multiple client sessions through Oracle Connection Manager to ensure that those sessions have continuous access to an Oracle Database server. This functionality is especially useful for web applications where session availability and response time are major concerns.
1-8 Oracle Database Net Services Administrator's Guide
About Oracle Net Services
Figure 1-10 Session Multiplexing
Client
Web
Browser
Application
Web Server
Oracle
Connection
Manager
Client
Web
Browser
Database
Server
RDBMS
Oracle
Net
Client
Web
Browser
The following are the advantages and disadvantages of session multiplexing. Session multiplexing is recommended for networks where continuous connectivity is required.
Advantages of Session Multiplexing
• Limits the number of network resources used for each process
• Supports large client populations
• Maximizes the number of client/server sessions over a limited number of process connections
• Optimizes resource utilization
• Enables identification and monitoring of real users
• Enables mid-tier applications to support additional services
• Requires only a single transport for clients with multiple applications
• Requires only a single network connection for database links
Disadvantage of Session Multiplexing
Clients must connect to Oracle Connection Manager.
1.1.4 Understanding Performance
System performance is important to users. Users usually start to notice performance when a system takes longer than one second to respond. Oracle Net configuration can be modified to enhance system performance.
This section discusses performance considerations. It contains the following topics:
•
(page 1-10)
•
Session Data Unit Size for Data Transfer Optimization (page 1-10)
Introducing Oracle Net Services 1-9
About Oracle Net Services
•
Persistent Buffer Flushing for TCP/IP (page 1-11)
•
(page 1-11)
•
(page 1-11)
1.1.4.1 Listener Queue Size
If you anticipate receiving a large number of connection requests for a listening process (such as a listener or Oracle Connection Manager) over TCP/IP, then Oracle
Net enables you to configure the listening queue to be higher than the system default.
1.1.4.2 Session Data Unit Size for Data Transfer Optimization
Before sending data across the network, Oracle Net buffers and encapsulates data into the
. Oracle Net sends the data stored in this buffer when the
buffer is full, flushed, or when database server tries to read data. When large amounts of data are being transmitted or when the message size is consistent, adjusting the size of the SDU buffers can improve performance, network utilization, or memory consumption. You can deploy SDU at the client, application web server, and database.
Tuning your application to reduce the number of round trips across the network is the best way to improve your network performance. If this is done, then it is also possible to optimize data transfer by adjusting the size of the SDU.
Considerations for Modifying the Size of the SDU
Modify the SDU size under the following situations:
• The data coming back from the server is fragmented into separate packets.
• You are on a wide area network (WAN) that has long delays.
• The packet size is consistently the same.
• Large amounts of data are returned.
Do not modify the SDU size under the following situations:
• The application can be tuned to avoid the delays listed in the adjacent column.
• You have a high speed network where the effect of the data transmission is negligible.
• Your requests return small amounts of data from the server.
Note:
Starting with Oracle Database 11g, Oracle Net Services optimizes bulk data transfer for certain components, such as Oracle SecureFiles LOBs and Oracle
Data Guard redo transport services. The SDU size limit, as specified in the network parameter files, does not apply to these bulk data transfers.
See Also:
"
(page 14-1)"
1-10 Oracle Database Net Services Administrator's Guide
About Oracle Net Services
1.1.4.3 Persistent Buffer Flushing for TCP/IP
Under certain conditions for some applications using TCP/IP, Oracle Net packets may not get flushed immediately to the network. Most often, this behavior occurs when large amounts of data are streamed. The implementation of TCP/IP itself is the reason for the lack of flushing, causing unacceptable delays. To remedy this problem, specify no delays in the buffer flushing process.
See Also:
Oracle Database Net Services Reference
for additional information about the
TCP.NODELAY parameter
1.1.4.4 Sockets Direct Protocol
Oracle Net Services provides support for InfiniBand high-speed networks. InfiniBand is a high-bandwidth I/O architecture designed to increase communication speed between CPUs, server-side devices, and network subsystems. Oracle Net Services
provides support for Sockets Direct Protocol (
). SDP is an industry-standard wire protocol intended for use between InfiniBand network peers.
SDP reduces the overhead of TCP/IP by eliminating intermediate replication of data and transferring most of the messaging burden away from the CPU and onto the network hardware. The result is a low-
, increased bandwidth, high-throughput
connection that reduces the amount of CPU cycles dedicated to network processing.
The communication between clients, including Oracle WebLogic Server or any other third-party middle-tier client, and Oracle Database 12c can take advantage of highspeed interconnect benefits. Oracle WebLogic Server includes Oracle TCP/IP support as part of its installation.
A driver installed on the Oracle WebLogic Server servers transparently converts
TCP/IP support to SDP support. The SDP requests are then sent to an InfiniBand switch that processes and forwards the requests from the Oracle WebLogic Server servers to the database server.
See Also:
"
Configuring SDP Support for InfiniBand Connections
(page 14-6)"
1.1.4.5 Database Availability
Availability to the database is crucial for any network. You can configure multiple listeners to handle client connection requests for the same database service. This is beneficial in Oracle Real Application Clusters configurations, where each instance has a listener associated with it. Multiple listener configurations enable you to use the following features.
• Connect-time failover enables clients to request a different listener, usually on a different node, if the first listener fails.
• Client load balancing enables clients to randomize requests to the multiple listeners, usually on different nodes. These features can be used together or separately. Together, they ensure access to the database and distribute the load to not overburden a single listener.
Introducing Oracle Net Services 1-11
About Oracle Net Services
1.1.5 Understanding Network Security
Data access and the secure transfer of data are important considerations when deploying Oracle Database. Granting and denying access to a database is crucial for a secure network environment. Oracle Net Services enables database access control using firewall access control and valid node registration.
See Also:
"
Managing Oracle Net Listener Security
(page 9-12)" for information about valid node registration
1.1.5.1 Firewall Access Control
Oracle Connection Manager can be configured to grant or deny client access to a particular database service or a computer. By specifying filtering rules, you can allow or restrict specific client access to a server, based on the following criteria:
• Source host names or IP addresses for clients
• Destination host names or IP addresses for servers
• Destination database service names
• Client use of Oracle Net Services security features
(page 1-12) shows an Oracle Connection Manager positioned between three clients and an Oracle Database server. Oracle Connection Manager is configured to allow access to the first two clients and to deny access to the third.
Figure 1-11 Intranet Network Access Control with Oracle Connection Manager
Client
Departmental
Firewall
Oracle Connection
Manager
Database
Server
Client
Acess is denied to this Client
Although Oracle Connection Manager cannot be integrated with third-party firewall products, vendors can package it with their own products in a way that enables this product to serve as an application gateway.
1-12 Oracle Database Net Services Administrator's Guide
Understanding Database Instances
In general, firewalls should be set to receive incoming requests, and allow outbound calls from Oracle Database. By defining filtering rules, you can limit access to the network.
Caution:
Incorrectly setting your firewall options can cause security problems. Before changing your firewall settings, discuss the options and your network site policies with your system administrator.
(page 1-13) shows an application gateway controlling traffic between internal and external networks and providing a single checkpoint for access control and auditing. As a result, unauthorized Internet hosts cannot directly access the database inside a corporation, but authorized users can still use Internet services outside the corporate network. This capability is critical in Internet environments to restrict remote access to sensitive data.
Figure 1-12 Internet Network Access Control with an Application Gateway
Demilitarized
Zone (DMZ)
Corporate
Network
Application
Gateway
Internet
Intranet
Databases
Clients
Application
Web Server
It is important to deploy at least two Oracle Connection Manager firewalls or Oracle
Net Firewall proxies in an Internet network environment in the event that one firewall goes down.
1.2 Understanding Database Instances
A database has at least one
. An instance is comprised of a memory area called
the
and Oracle background processes. The memory and processes of an instance efficiently manage the associated database's data and serve the database users.
Note:
An instance also manages other services, such as
.
Introducing Oracle Net Services 1-13
Understanding Database Instances
Figure 2-1 (page 2-2) shows two database instances,
sales
and finance
, associated with their respective databases and service names.
Figure 1-13 One Instance for Each Database
Salesperson Database
Server sales.us.example.com
Financial Analyst finance.us.example.com
sales
Database
Server finance
Instances are identified by an
sales
and finance
in this example. The instance name is specified by the INSTANCE_NAME initialization parameter. The instance name defaults to the
Oracle system identifier (SID)
of the database instance.
Some hardware architectures allow multiple computers to share access to data, software, or peripheral devices.
Oracle Real Application Clusters (Oracle RAC)
take advantage of such architecture by running multiple instances on different computers that share a single physical database.
Figure 2-2 (page 2-2) shows an Oracle RAC configuration. In this example, two
instances, sales1
and sales2
, are associated with one database service, sales.us.example.com
.
1-14 Oracle Database Net Services Administrator's Guide
Components of Oracle Net Services
Figure 1-14 Multiple Instances Associated with an Oracle RAC Database
Cluster
Node sales.us.example.com
Oracle RAC
Database sales1
Cluster
Node sales.us.example.com
sales2
1.3 Components of Oracle Net Services
The connectivity, manageability, scalability, and security features are described in the following sections:
•
(page 1-15)
•
(page 1-16)
•
About Oracle Connection Manager
(page 1-17)
•
About Networking Tools (page 1-17)
•
About Oracle Advanced Security (page 1-18)
1.3.1 About Oracle Net
Oracle Net is a software layer that resides on the client and on the Oracle Database server. It is responsible for establishing and maintaining the connection between the client application and server, as well as exchanging messages between them, using industry-standard protocols. Oracle Net has two software components:
•
(page 1-15)
•
(page 1-16)
1.3.1.1 Oracle Net Foundation Layer
On the client side, applications communicate with Oracle Net foundation layer to establish and maintain connections. The Oracle Net foundation layer uses Oracle protocol support that communicates with an industry-standard network protocol, such as TCP/IP, to communicate with the Oracle Database server.
(page 1-16) illustrates the communication stack on the client.
Introducing Oracle Net Services 1-15
Components of Oracle Net Services
Figure 1-15 Oracle Net on the Client
Application
Oracle Net
Foundation
Layer
Oracle
Protocol
Support
Network
Protocol
The Oracle Database server side is similar to the client side as illustrated in Figure 1-16
(page 1-16). A network protocol sends client request information to an Oracle protocol support layer, which then sends information to the Oracle Net foundation layer. The Oracle Net foundation layer then communicates with the Oracle Database server to process the client request.
Figure 1-16 Oracle Net on the Server
RDBMS
Oracle Net
Foundation
Layer
Oracle
Protocol
Support
Network
Protocol
1.3.1.2 Oracle Protocol Support
The Oracle Net foundation layer uses Oracle protocol support to communicate with the following industry-standard network protocols:
• TCP/IP (version 4 and version 6)
• TCP/IP with SSL
• Named Pipes
• SDP
Oracle protocol support maps Oracle Net foundation layer functionality to industrystandard protocols used in client/server connections.
See Also:
"
Understanding Oracle Protocol Support Layer
(page 4-7)"
1.3.2 About Oracle Net Listener
Oracle Database server receives the initial connection through
Oracle Net Listener, referred to in this document as the
, brokers a client request, handing off the request to the server. The listener is configured with a protocol address, and clients configured with the same protocol address can send connection requests to the listener. When a connection is established, the client and
Oracle server communicate directly with one another.
1-16 Oracle Database Net Services Administrator's Guide
Components of Oracle Net Services
Oracle Net listener supports ACLs (Access Control Lists) for service and this is supported for all IP protocols.
See Also:
DBSFWUSER.DBMS_SFW_ACL_ADMIN in Oracle Database
PL/SQL Packages and Types Reference
for more information about listener ACLs
(page 1-17) shows the listener accepting a connection request from a client and forwarding that request to an Oracle server.
Figure 1-17 Listener in a Connection Request
Database Server Computer
Client
Application
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Network
Protocol
Listener
RDBMS
Oracle Net
Foundation
Layer
Oracle Protocol
Support
See Also:
Configuring and Administering Oracle Net Listener (page 9-1) for
additional information about the listener
1.3.3 About Oracle Connection Manager
Oracle Connection Manager is the software component that resides on its own computer, separate from a client or an Oracle Database server. It proxies and screens requests for the database server. In addition, it multiplexes database sessions.
In its session multiplexing role, Oracle Connection Manager funnels multiple sessions through a single transport protocol connection to a particular destination. In this way,
Oracle Connection Manager reduces the demand on resources needed to maintain multiple sessions between two processes by enabling the Oracle Database server to use fewer connection endpoints for incoming requests.
As an access control filter, Oracle Connection Manager controls access to Oracle databases.
See Also:
•
" Understanding Shared Server Architecture (page 1-7)"
•
(page 1-12)" for a description of filtering
1.3.4 About Networking Tools
Oracle Net Services provides user interface tools and command-line utilities to configure, manage, and monitor the network.
Introducing Oracle Net Services 1-17
Components of Oracle Net Services
•
Oracle Net Configuration Assistant
is a standalone tool that enables you to
configure listeners and naming methods.
•
Oracle Enterprise Manager Cloud Control
combines configuration functionality
across multiple file systems, along with listener administrative control to provide an integrated environment for configuring and managing Oracle Net Services.
•
provides configuration functionality for an Oracle home on a local client or server host.
• Command-line control utilities to configure, administer, and monitor network components, including listeners and Oracle Connection Managers.
With Oracle Enterprise Manager Cloud Control or Oracle Net Manager, you can finetune the listener and naming method configuration created with Oracle Net
Configuration Assistant. In addition, Oracle Enterprise Manager Cloud Control and
Oracle Net Manager offer built-in wizards and utilities to test connectivity, migrate data from one naming method to another, and create additional network components.
See Also:
Managing Oracle Net Services (page 7-1)
1.3.5 About Oracle Advanced Security
Oracle Advanced Security is a separately licensable product that provides Oracle
Database Transparent Data Encryption (TDE) and Oracle Data Redaction. TDE encrypts data so that only an authorized recipient can read it. Oracle Data Redaction enables an administrator to redact (mask) column data, using the following types of redaction:
• Full redaction redacts all the contents of the column data. The redacted value returned to the querying user depends on the data type of the column. For example, columns of the NUMBER data type are redacted with a zero (0) and character data types are redacted with a blank space.
• Partial redaction redacts a portion of the column data. For example, masking most of a credit card number with asterisks (*), except for the last four digits.
• Regular expressions enable using patterns of data to redact. For example, use regular expressions to redact email addresses, which can have varying character lengths. It is designed for use with character data only.
• Random redaction present the redacted data to the querying user as randomlygenerated values each time it is displayed.
• No redaction enables an administrator to test the internal operation of the redaction policies, with no effect on the results of queries against tables with policies defined on them.
See Also:
Oracle Database Advanced Security Guide
1-18 Oracle Database Net Services Administrator's Guide
2
Identifying and Accessing the Database
Understand how databases are identified, and how clients access them.
•
Understanding Database Instances
(page 2-1)
•
Understanding Database Services
(page 2-3)
•
Connecting to a Database Service
(page 2-4)
•
Understanding Service Handlers (page 2-9)
•
Understanding Naming Methods (page 2-13)
•
Enhancing Service Accessibility Using Multiple Listeners
(page 2-17)
2.1 Understanding Database Instances
A database has at least one
. An instance is comprised of a memory area called
the
and Oracle background processes. The memory and processes of an instance efficiently manage the associated database's data and serve the database users.
Note:
An instance also manages other services, such as
.
Figure 2-1 (page 2-2) shows two database instances,
sales
and finance
, associated with their respective databases and service names.
Identifying and Accessing the Database 2-1
Understanding Database Instances
Figure 2-1 One Instance for Each Database
Salesperson sales.us.example.com
Database
Server
Financial Analyst finance.us.example.com
sales
Database
Server finance
Instances are identified by an
sales
and finance
in this example. The instance name is specified by the INSTANCE_NAME initialization parameter. The instance name defaults to the
Oracle system identifier (SID)
of the database instance.
Some hardware architectures allow multiple computers to share access to data, software, or peripheral devices.
Oracle Real Application Clusters (Oracle RAC)
take advantage of such architecture by running multiple instances on different computers that share a single physical database.
Figure 2-2 (page 2-2) shows an Oracle RAC configuration. In this example, two
instances, sales1
and sales2
, are associated with one database service, sales.us.example.com
.
Figure 2-2 Multiple Instances Associated with an Oracle RAC Database
Cluster
Node sales.us.example.com
Oracle RAC
Database sales1
Cluster
Node sales.us.example.com
sales2
2-2 Oracle Database Net Services Administrator's Guide
Understanding Database Services
2.2 Understanding Database Services
An Oracle database is represented to clients as a
more services associated with it.
Figure 2-3 (page 2-3) shows two databases, each with its own database service for
clients. One service, sales.us.example.com
, enables salespersons to access the sales database. Another service, finance.us.example.com
, enables financial analysts to access the finance database.
Figure 2-3 One Service for Each Database
Salesperson
Database
Server sales.us.example.com
Financial Analyst finance.us.example.com
Database
Server
The sales and finance databases are each identified by a
sales.us.example.com
and finance.us.example.com
, respectively. A service name is a logical representation of a database. When an instance starts, it registers itself with a listener using one or more service names. When a client program or database connects to a listener, it requests a connection to a service.
A service name can identify multiple database instances, and an instance can belong to multiple services. For this reason, the listener acts as a mediator between the client and instances and routes the connection request to the appropriate instance. Clients connecting to a service need not specify which instance they require.
The service name is specified by the SERVICE_NAMES initialization parameter in the
. The server parameter file enables you to change initialization
parameters with
ALTER SYSTEM
commands, and to carry the changes across a shutdown and startup. The DBMS_SERVICE package can also be used to create services. The service name defaults to the
, a name comprising the database name (DB_NAME initialization parameter) and domain name
(DB_DOMAIN initialization parameter). In the case of sales.us.example.com
, the database name is sales
and the domain name is us.example.com
.
Figure 2-4 (page 2-4) shows clients connecting to multiple services associated with
one database.
Identifying and Accessing the Database 2-3
Connecting to a Database Service
Figure 2-4 Multiple Services Associated with One Database
book.us.example.com
Database Server soft.us.example.com
Associating multiple services with one database enables the following functionality:
• A single database can be identified different ways by different clients.
• A database administrator can limit or reserve system resources. This level of control enables better allocation of resources to clients requesting one of the services.
See Also:
•
Oracle Database Administrator's Guide
for additional information about initialization parameters
•
Oracle Database SQL Reference
for additional information about the
ALTER
SYSTEM
statement
•
Oracle Database Reference
for additional information about the
SERVICE_NAMES parameter
•
Oracle Database PL/SQL Packages and Types Reference
for additional information about the DBMS_SERVICE package.
2.3 Connecting to a Database Service
To connect to a database service, clients use a
that provides the location of the database and the name of the database service. The following example is an Easy Connect descriptor that connects to a database service named sales.us.example.com
, and the host sales-server
(the port is 1521 by default): sales-server/sales.us.example.com
The following example shows the entry in the tnsnames.ora
file for the preceding
Easy Connect connect descriptor and database service:
2-4 Oracle Database Net Services Administrator's Guide
Connecting to a Database Service
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(
HOST=sales-server
)(PORT=1521))
(CONNECT_DATA=
(
SERVICE_NAME=sales.us.example.com
)))
This section contains the following topics:
•
(page 2-5)
•
(page 2-7)
•
About Service Registration (page 2-7)
See Also:
"
(page 2-13)"
2.3.1 About Connect Descriptors
A connect descriptor is comprised of one or more protocol addresses of the listener and the connect information for the destination service in the tnsnames.ora
file.
Example 2-1 (page 2-5) shows a connect descriptor mapped to the
sales
database.
Example 2-1 Connect Descriptor
sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SID=sales)
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_NAME=sales)))
As shown in
Example 2-1 (page 2-5), the connect descriptor contains the following
parameters:
• The ADDRESS section contains the following:
– PROTOCOL parameter, which identifies the listener protocol address. The protocol is tcp
for TCP/IP.
– HOST parameter, which identifies the host name. The host is salesserver
.
– PORT parameter, which identifies the port. The port is
1521
, the default port number.
– Optional HTTPS_PROXY and HTTPS_PROXY_PORT parameters, that allow the database client connection to traverse through the organization’s forward web proxy. These parameters are applicable only to the connect descriptors where PROTOCOL=TCPS.
• The CONNECT_DATA section contains the following:
– SID parameter, which identifies the system identifier (SID) of the Oracle database. The SID is sales
.
Identifying and Accessing the Database 2-5
Connecting to a Database Service
– SERVICE_NAME parameter, which identifies the service. The destination service name is a database service named sales.us.example.com
.
The value for this connect descriptor parameter comes from the
SERVICE_NAMES initialization parameter (SERVICE_NAMES uses a final S) in the initialization parameter file. The SERVICE_NAMES initialization parameter is typically the
name and domain name. In the example, sales.us.example.com
has a database name of sales
and a domain of us.example.com
.
– INSTANCE_NAME parameter, which identifies the database instance. The instance name is optional.
The INSTANCE_NAME parameter in the initialization parameter file defaults to the SID entered during installation or database creation.
See Also:
"
Understanding Database Instances
(page 2-1)", and " Understanding Database
(page 2-3)"
2.3.1.1 About IPv6 Addresses in Connect Descriptors
A host can use IP version 4 (IPv4) and IP version 6 (IPv6) interfaces. IPv6 addresses and host names that resolve to IPv6 addresses are usable in the HOST parameter of a
TNS connect address, which can be obtained through any of the supported net naming
methods listed in Table 2-1 (page 2-14).
End-to-end connectivity using IPv6 in Oracle Database 12c requires the following configuration:
• The client TNS connect address must connect to the Oracle Net Listener on the
IPv6 endpoint.
• The database instance configured for Oracle Net Listener must listen for connection requests on IPv6 endpoints.
For a given host name, Oracle Net attempts to connect to all IP addresses returned by
Domain Name System (DNS) name resolution until a successful connection is
established or all addresses have been attempted. Suppose that in Example 2-1
(page 2-5) the sales-server
host is an IPv4-only host that is accepting client connections. DNS maps sales-server
to the following IP addresses:
1.
IPv6 address
2001:0db8:0:0::200C:417A
2.
IPv4 address
192.0.2.213
In this case, Oracle Net first tries to connect on the IPv6 address because it is first in the DNS list. In this example, sales-server
does not support IPv6 connectivity, so this attempt fails. Oracle Net proceeds to connect to the IPv4 address, which succeeds.
2-6 Oracle Database Net Services Administrator's Guide
Connecting to a Database Service
See Also:
•
" About TCP/IP Protocol (page 4-7)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
" Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
(page 10-8)"
•
(page 4-10)"
2.3.2 About the Protocol Address
The address portion of the connect descriptor is the protocol address of the
To connect to a database service, clients first contact a listener process that typically resides on the database server. The listener receives incoming client connection requests and sends these requests to the database server. After the connection is established, the client and database server communicate directly.
The listener is configured to accept requests from clients at a
address defines the protocol the listener is listening on and any other protocol-specific information. For example, the listener could be configured to listen at the following protocol address:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)))
The preceding example shows a TCP/IP protocol address that specifies the host of the listener and a port number. Client connect descriptors configured with this same protocol address can send connection requests to this listener.
2.3.3 About Service Registration
The connect descriptor specifies the database service name with which clients seek to establish a connection. The listener knows which services can handle connection requests because Oracle Database dynamically registers this information with the
listener. This process of registration is called
provides the listener with information about the database instances and the service
handlers available for each instance. A service handler can be a
or
.
2.3.3.1 Specifying an Instance Name
If connecting to a specific instance of the database is required, then clients can specify the INSTANCE_NAME of a particular instance in the connect descriptor. This feature can be useful for an Oracle RAC configuration. For example, the following connect descriptor specifies the instance name sales1
that is associated with sales.us.example.com
.
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_NAME=sales1)))
Identifying and Accessing the Database 2-7
Connecting to a Database Service
2.3.3.2 Specifying a Service Handler
Clients that always want to use a particular service handler type can use a connect descriptor to specify the service handler type. In the following example, the connect descriptor uses
(SERVER=shared)
to request a dispatcher when connecting to a database. The database may be configured to use dedicated servers by default.
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(SERVER=shared)))
When the listener receives the client request, it selects one of the registered service handlers. Depending on the type of handler selected, the communication protocol used, and the operating system of the database server, the listener performs one of the following actions:
• Hands the connect request directly off to a dispatcher.
• Sends a redirect message back to the client with the location of the dispatcher or dedicated server process. The client then connects directly to the dispatcher or dedicated server process.
• Spawns a dedicated server process and passes the client connection to the dedicated server process.
After the listener has completed the connection operation for the client, the client communicates directly with the Oracle database without the listener's involvement.
The listener resumes listening for incoming network sessions.
The following should be considered when specifying service handlers:
• If you want the client to use a dedicated server, then specify
(SERVER=dedicated)
. If the SERVER parameter is not set, then a shared server configuration is assumed. However, the client will use a dedicated server if no dispatchers are available.
• If database resident connection pooling is enabled on the server, then specify
(SERVER=pooled)
to get a connection from the pool. If database resident connection pooling is not enabled on the server, then the client request is rejected, and the user receives an error message.
See Also:
•
" About the Listener and Connection Requests
(page 5-2)" for a discussion about how the listener works with service handlers
•
Oracle Call Interface Programmer's Guide
and Oracle Database Administrator's
Guide
•
Oracle Database Global Data Services Concepts and Administration Guide
for additional information about management of global services
2-8 Oracle Database Net Services Administrator's Guide
Understanding Service Handlers
2.4 Understanding Service Handlers
Service handlers act as connection points to an Oracle database. A service handler can
or a
process, or pooled.
This section contains the following topics:
•
(page 2-9)
•
About Dedicated Server Processes (page 2-10)
•
About Database Resident Connection Pooling
(page 2-12)
2.4.1 About Dispatchers
The shared server architecture uses a dispatcher process to direct client connections to a common request queue. An idle shared server process from a shared pool of server processes picks up a request from the common queue. This approach enables a small pool of server processes to serve a large number of clients. A significant advantage of the shared server model over the dedicated server model is reduced system resources, enabling support of an increased number of users.
The listener uses the dispatcher as a type of
client requests. When a client request arrives, the listener performs one of the following actions:
• Hands the connection request directly to a dispatcher.
• Issues a redirect message to the client, containing the protocol address of a dispatcher. The client then terminates the network session to the listener and establishes a network session to the dispatcher, using the network address provided in the redirect message.
The listener uses direct hand off whenever possible. Redirect messages are used, for example, when dispatchers are remote to the listener.
Figure 2-5 (page 2-10) shows the listener handing a connection request directly to a
dispatcher.
1.
The listener receives a client connection request.
2.
3.
The listener hands the connect request directly to the dispatcher.
The client is now connected to the dispatcher.
Identifying and Accessing the Database 2-9
Understanding Service Handlers
Figure 2-5 Direct Hand Off to a Dispatcher
Database Instance
3
Shared
Server
Process
Client Dispatcher
1 2
Listener
Shared
Server
Process
Database
Pool of shared server processes
Figure 2-6 (page 2-10) shows the role of a dispatcher in a redirected connection.
1.
The listener receives a client connection request.
2.
3.
The listener provides the location of the dispatcher to the client in a redirect message.
The client connects directly to the dispatcher.
Figure 2-6 Redirected Connection to a Dispatcher
Client
3
Database Instance
Shared
Server
Process
Dispatcher
1
2
Listener
Database
Shared
Server
Process
Pool of shared server processes
2.4.2 About Dedicated Server Processes
In a dedicated server configuration, the listener starts a separate dedicated server process for each incoming client connection request dedicated to servicing the client.
After the session is complete, the dedicated server process terminates. Because a dedicated server process has to be started for each connection, this configuration may require more system resources than shared server configurations.
2-10 Oracle Database Net Services Administrator's Guide
Understanding Service Handlers
A dedicated server process is a type of service handler that the listener starts when it receives a client request. To complete a client/server connection, one of the following actions occurs:
• The dedicated server inherits the connection request from the listener.
• The dedicated server informs the listener of its listening protocol address. The listener passes the protocol address to the client in a redirect message and terminates the connection. The client connects to the dedicated server directly using the protocol address.
One of the preceding actions is selected based on the operating system and the transport protocol.
If the client and database exist on the same computer, then a client connection can be passed directly to a dedicated server process without going through the listener. This is known as a bequeath protocol. The application initiating the session spawns a dedicated server process for the connection request. This happens automatically if the application used to start the database is on the same computer as the database.
Note:
In order for remote clients to connect to dedicated servers, the listener and the database instance must be running on the same computer.
Figure 2-7 (page 2-11) shows the listener passing a client connection request to a
dedicated server process.
1.
The listener receives a client connection request.
2.
3.
The listener starts a dedicated server process, and the dedicated server inherits the connection request from the listener.
The client is now connected directly to the dedicated server.
Figure 2-7 Connection to a Dedicated Server Process
Database Instance
3
Client
1
Listener
2
Dedicated
Server
Process
Database
Figure 2-8 (page 2-12) shows the role of a dedicated server in a redirected connection.
1.
The listener receives a client connection request.
2.
3.
4.
The listener starts a dedicated server process.
The listener provides the location of the dedicated server process to the client in a redirect message.
The client connects directly to the dedicated server.
Identifying and Accessing the Database 2-11
Understanding Service Handlers
Figure 2-8 Redirected Connection to a Dedicated Server Process
Database Instance
4
Client
1
3
Listener
2
Dedicated
Server
Process
Database
2.4.3 About Database Resident Connection Pooling
Database resident connection pooling provides a connection pool in the database server for typical web application usage scenarios in which an application acquires a database connection, works on it for a relatively short duration, and then releases it.
Database resident connection pooling pools "dedicated" servers. A pooled server is the equivalent of a server foreground process and a database session combined. Database resident connection pooling uses dynamic registration between the server and the listener. It cannot use static registration.
Database resident connection pooling complements middle-tier connection pools that share connections between threads in a middle-tier process. In addition, it enables sharing of database connections across middle-tier processes on the same middle-tier host and even across middle-tier hosts. This results in significant reduction in key database resources needed to support a large number of client connections, thereby reducing the database tier memory footprint and boosting the scalability of both middle-tier and database tiers. Having a pool of readily available servers has the additional benefit of reducing the cost of creating and closing client connections.
Database resident connection pooling provides pooling for
across client applications and processes. This feature is useful for applications that must maintain persistent connections to the database and optimize server resources, such as memory.
Clients obtaining connections out of the database resident connection pool are persistently connected to a background process, the connection broker, instead of the dedicated servers. The connection broker implements the pool functionality and performs the multiplexing of inbound connections from the clients to a pool of dedicated servers with sessions.
When a client must perform database work, the connection broker picks up a dedicated server from the pool and assigns it to the client. Subsequently, the client is directly connected to the dedicated server until the request is served. After the server finishes processing the client request, the server goes back into the pool and the connection from the client is restored to the connection broker.
Figure 2-9 (page 2-13) shows the process.
2-12 Oracle Database Net Services Administrator's Guide
Understanding Naming Methods
Figure 2-9 Dedicated Server Processes Handling Connections Through the Connection Broker
Process
Client process
1
Client process
2
Host 1
Client process
3
. . .
Client process n
Client process
1
Client process
2
Host 2
Client process
3
. . .
Client process n
Direct connection after handoff
Persistent connections
Connection
Broker
Hand off
Hand back
System Global Area
Pool of dedicated server processes
2.5 Understanding Naming Methods
A naming method is a resolution method used by a client application to resolve a connect identifier to a connect descriptor when attempting to connect to a database service. Users initiate a connection request by providing a
. A connect string includes a user name and password, along with a
. A connect identifier can be the connect descriptor or a name that resolves to a connect descriptor.
The connect descriptor contains:
• Network route to the service, including the location of the listener through a protocol address
•
or
Oracle system identifier (SID)
The following
CONNECT
command uses a connect string that has a complete connect descriptor as the connect identifier instead of a network service name. The string should be entered on a single line. It is shown on two lines because of page width.
SQL> CONNECT hr@(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server1)
(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))
One of the most common connect identifiers is a
, a simple name for a service. The following
CONNECT
command uses a connect string that uses network service name sales
as the connect identifier:
SQL> CONNECT hr@sales
Identifying and Accessing the Database 2-13
Understanding Naming Methods
When network service name sales
is used, connection processing takes place by first mapping sales
to the connect descriptor. This mapped information is accessed by
s. The following naming methods are available:
• Local naming
• Directory naming
• Easy Connect naming
• External naming
2.5.1 Choosing a Naming Method
Selecting the appropriate naming method for mapping names to connect descriptors depends upon the size of the organization.
• For a small organization with only a few databases, use Easy Connect naming to make TCP/IP connections with the host name of the database server or local naming to store names in tnsnames.ora
file on the clients.
• For large organizations with several databases, use directory naming to store names in a centralized directory server.
• For an Internet network, configure the application web servers needed to connect to the databases with the local naming method.
(page 2-14) summarizes the relative advantages and disadvantages of each naming method and provides recommendations for using them in the network.
Table 2-1 Naming Methods: Advantages and Disadvantages
Naming Method Description
Local Naming Stores network service names and their connect descriptors in a localized configuration file named tnsnames.ora
, which by default is located in the network/admin subdirectory under the
Oracle Database home.
Advantages/Disadvantages
Advantages
:
• Provides a straightforward method for resolving network service name addresses.
• Resolves network service names across networks running different protocols.
Disadvantage
: Requires local configuration of all network service name and address changes.
Recommended for:
Simple distributed networks with a small number of services that change infrequently.
2-14 Oracle Database Net Services Administrator's Guide
Understanding Naming Methods
Table 2-1 (Cont.) Naming Methods: Advantages and Disadvantages
Naming Method Description
Directory
Naming
Stores connect identifiers in a centralized LDAPcompliant
database service.
Advantages/Disadvantages
Advantages
:
• Centralizes network names and addresses in a single place, facilitating administration of name changes and updates. This eliminates the need for an administrator to make changes to what potentially could be hundreds or even thousands of clients.
• Directory stores names for other services.
• Tools provide simple configuration.
Disadvantage
: Requires access to a directory server.
Recommended for:
Large, complex networks (over 20 databases) that change on a frequent basis.
Easy Connect
Naming
Enables clients to connect to an Oracle database server by using a TCP/IP connect string consisting of a host name and optional port and service name.
Advantages
:
• Requires minimal user configuration. The user can provide only the name of the database host to establish a connection.
• The easy naming method requires no client-side configuration.
• Eliminates the need to create and maintain a local names configuration file
( tnsnames.ora
).
Disadvantage
: Available only in a limited environment, as indicated in the
Recommended for
column.
External Naming Stores network service names in a supported third-party naming
Advantage
: Enables administrators to load Oracle network service name into their native name service using tools and utilities with which they are already familiar.
Disadvantage
: Requires third-party naming services that cannot be administered using Oracle Net products.
Simple TCP/IP networks that meet the following criteria:
• The client and server are connecting using
TCP/IP.
• No features requiring a more advanced connect descriptor are required.
Networks with existing name services.
A naming method configuration consists of the following steps:
1.
2.
3.
Select a naming method.
Map connect descriptors to the names.
Configure clients to use the naming method.
2.5.2 Establishing a Client Session Using a Naming Method
A typical process for establishing a client session using a naming method is as follows:
Identifying and Accessing the Database 2-15
Understanding Naming Methods
1.
2.
3.
4.
5.
The client initiates a connect request by providing a connect identifier.
The connect identifier is resolved to a connect descriptor by a naming method.
The client makes the connection request to the address provided in the connect descriptor.
A listener receives the request and directs it to the appropriate database server.
The connection is accepted by the database server.
Note:
Besides connect descriptors, you can use naming methods to map a connect name to a protocol address or protocol address list.
2.5.3 Entering a Connect String
After the network components are started you should be able to make a connection
across the network. How you make a connection depends upon the
and the tool used for the connection.
The
takes the following format:
CONNECT
username
@
connect_identifier
On most operating systems, you can define a default
the default, a connect identifier does not need to be specified in the connect string. To define a default connect identifier, use the TWO_TASK environment variable on Linux and UNIX platforms or the LOCAL environment variable or registry entry on
Microsoft Windows.
For example, if the TWO_TASK environment variable is set to sales
, then you can connect to a database from SQL*Plus with
CONNECT username
rather than
CONNECT
username@sales
. Oracle Net checks the TWO_TASK variable, and uses the value sales
as the connect identifier.
See Also:
Oracle operating system-specific documentation for instructions on setting the
TWO_TASK and LOCAL environment variables
2.5.3.1 Connect Identifier and Connect Descriptor Syntax Characteristics
Connect identifiers used in a connect string cannot contain spaces, unless enclosed within single quotation marks (') or double quotation marks ("). In the following examples, a connect identifier and a connect descriptor that contain spaces are enclosed within single quotation marks:
CONNECT scott@'(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)
(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))'
Enter password:
password
CONNECT scott@'cn=sales, cn=OracleContext, dc=us, dc=example, dc=com'
Enter password:
password
2-16 Oracle Database Net Services Administrator's Guide
Enhancing Service Accessibility Using Multiple Listeners
Single quotation marks are required if double quotation marks are used in a connect identifier. For example:
CONNECT scott@'sales@"good"example.com'
Enter password:
password
Similarly, double quotation marks are required if a single quotation marks are used in a connect identifier. For example:
CONNECT scott@"cn=sales, cn=OracleContext, ou=Mary's Dept, o=example"
Enter password:
password
2.6 Enhancing Service Accessibility Using Multiple Listeners
For some configurations, such as Oracle RAC, multiple listeners on multiple nodes can be configured to handle client connection requests for the same database service. In the following example, sales.us.example.com
can connect using listeners on either sales1-server
or sales2-server
.
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
A multiple-listener configuration also enables you to leverage the failover and load balancing features, either individually or in combination with each other. The following topics describe the features:
•
About Connect-time Failover (page 2-17)
•
About Transparent Application Failover
(page 2-17)
•
About Client Load Balancing (page 2-17)
•
About Connection Load Balancing (page 2-18)
2.6.1 About Connect-Time Failover
The
feature enables clients to connect to another listener if the initial connection to the first listener fails. The number of listener protocol addresses determines how many listeners are tried. Without connect-time failover, Oracle Net attempts a connection with only one listener.
2.6.2 About Transparent Application Failover
The
Transparent Application Failover (TAF)
feature is a runtime failover for high
availability environments, such as Oracle Real Application Clusters. TAF fails over and reestablishes application-to-service connections. It enables client applications to automatically reconnect to the database if the connection fails and, optionally, resume a
SELECT
statement that was in progress. The reconnection happens automatically
2.6.3 About Client Load Balancing
The
feature enables clients to randomize connection requests among the listeners. Oracle Net progresses through the list of protocol addresses in a
Identifying and Accessing the Database 2-17
Enhancing Service Accessibility Using Multiple Listeners random sequence, balancing the load on the various listeners. Without client load balancing, Oracle Net progresses through the list of protocol addresses sequentially until one succeeds.
2.6.4 About Connection Load Balancing
The
feature improves connection performance by
balancing the number of active connections among multiple dispatchers. In a singleinstance environment, the listener selects the least-loaded dispatcher to handle the incoming client requests. In an Oracle Real Application Clusters environment, connection load balancing can balance the number of active connections among multiple instances.
Due to dynamic service registration, a listener is always aware of all instances and dispatchers regardless of their location. Depending on the load information, a listener decides which instance and, if shared server is configured, to which dispatcher to send the incoming client request.
In a shared server configuration, a listener selects a dispatcher in the following order:
1.
Least-loaded node
2.
Least-loaded instance
3.
Least-loaded dispatcher for that instance
In a dedicated server configuration, a listener selects an instance in the following order:
1.
Least-loaded node
2.
Least-loaded instance
If a database service has multiple instances on multiple nodes, then the listener chooses the least-loaded instance on the least-loaded node.
2-18 Oracle Database Net Services Administrator's Guide
3
Managing Network Address Information
Identify how the network address information for Oracle Net Services can be stored in local files or in a centralized directory server. Using localized management, network address information is stored in tnsnames.ora
files on each computer in the network. Using centralized management, network address information is stored in
.
The chapter contains the following topics:
•
(page 3-1)
•
Using a Directory Server for Centralized Management
(page 3-2)
3.1 Using Localized Management
When localized management is used, network computers are configured with the files described in
(page 3-1). The files are stored locally on the computers.
Table 3-1 Oracle Net Configuration Files Used with Localized Management
Configuration File
tnsnames.ora
sqlnet.ora
listener.ora
Description
Located primarily on the clients, this file contains
for the
Located on client and database server computers, this file may include the following:
• Client domain to append to unqualified service names or network service names
• Order of naming methods the client should use when resolving a name
• Logging and tracing features to use
• Route of connections
• External naming parameters
• Oracle security parameters
• Database access control parameters
Located on the database server, this configuration file for the
may include the following:
• Protocol addresses it is accepting connection requests on
• Database and nondatabase services it is listening for
• Control parameters used by the listener
Managing Network Address Information 3-1
Using a Directory Server for Centralized Management
Table 3-1 (Cont.) Oracle Net Configuration Files Used with Localized Management
Configuration File
cman.ora
Description
Located on the computer where Oracle Connection Manager runs, this configuration file includes the following components:
• A listening endpoint
• Access control rule list
• Parameter list
Each Oracle Connection Manager configuration is encapsulated within a single name-value (NV) string, which consists of the preceding components.
Configuration files are typically created in the
ORACLE_HOME/network/admin directory. However, configuration files can be created in other directories. Oracle Net checks the other directories for the configuration files. For example, the order for checking the tnsnames.ora
file is as follows:
1.
2.
The directory specified by the TNS_ADMIN environment variable. If the file is not found in the directory specified, then it is assumed that the file does not exist.
If the TNS_ADMIN environment variable is not set, then Oracle Net checks the
ORACLE_HOME/network/admin
directory.
Note:
On Microsoft Windows, the TNS_ADMIN environment variable is used if it is set in the environment of the process. If the TNS_ADMIN environment variable is not defined in the environment, or the process is a service which does not have an environment, then Microsoft Windows scans the registry for a TNS_ADMIN parameter.
See Also:
•
Oracle Database Global Data Services Concepts and Administration Guide
for information about the gsm.ora
file
• Operating system-specific documentation
3.2 Using a Directory Server for Centralized Management
When an Oracle network uses a directory server, the directory server manages global database links as network service names for the Oracle databases in the network.
Users and programs can use a global link to access objects in the corresponding database.
Oracle Net Services uses a centralized directory server as one of the primary methods
s. Clients use the connect identifiers in their connect
string, and the directory server resolves the connect identifier to a connect descriptor that is passed back to the client. This feature is called
. This type of infrastructure reduces the cost of managing and configuring resources in a network.
3-2 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
provides a centralized mechanism for managing and configuring a distributed Oracle network. The directory server can replace client-side and server-side localized tnsnames.ora
files.
Figure 3-1 (page 3-3) shows a client resolving a connect identifier through a
directory server.
1.
The client contacts the directory server to resolve a connect identifier to a connect descriptor.
2.
3.
The directory server resolves the connect identifier and retrieves the connect descriptor for the client.
The client sends the connection request to the listener, using the connect descriptor.
Figure 3-1 Client Using a Directory Server to Resolve a Connect Identifier
Database
Server
3
Listener
Client
1
2
Directory
Server
Note:
Java Database Connectivity (JDBC) Driver
s support directory naming. See
Oracle Database JDBC Developer's Guide
for additional information.
This section contains the following topics:
•
Understanding the Directory Information Tree (page 3-4)
•
Understanding Oracle Context (page 3-8)
•
Understanding Net Service Alias Entries (page 3-9)
•
Who Can Add or Modify Entries in the Directory Server (page 3-10)
•
Client Connections Using Directory Naming (page 3-11)
Managing Network Address Information 3-3
Using a Directory Server for Centralized Management
•
Considerations When Using Directory Servers (page 3-11)
•
Limitations of Directory Naming Support with Microsoft Active Directory
(page 3-16)
3.2.1 Understanding the Directory Information Tree
Directory servers store information in a hierarchical namespace structure called a
directory information tree (DIT)
. Each node in the tree is called an
Services uses both the tree structure and specific entries in the tree. DITs are commonly aligned with an existing domain structure such as a Domain Name System
(DNS) structure or a geographic and organization structure.
Figure 3-2 (page 3-4) shows a DIT structured according to DNS domain
components.
Figure 3-2 DNS Domain Component DIT
dc=com dc=example dc=us dc=jp cn=OracleContext cn=myproddb
Figure 3-3 (page 3-4) shows a DIT structured according to country, organization,
and organizational units. This structure is commonly referred to as an X.500 DIT.
Figure 3-3 X.500 DIT
c=us o=example ou=sales ou=mtkg cn=OracleContext cn=myproddb
For example, consider Figure 3-4
(page 3-5). The cn=sales
and cn=db1
entries represent a network service name and a database service, respectively. Additional entries under cn=sales
and cn=db1
contain the connect descriptor information.
These entries are not represented in the graphic. The cn=sales
and cn=db1
entries enable clients to connect to the database using connect strings
CONNECT
username@sales
and
CONNECT username@db1
.
3-4 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
Figure 3-4 Database Service and Net Service Entries in a DIT
dc=com dc=example
cn=db1
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=db1-server)
(PORT=1521))(CONNECT_DATA=
(SERVICE_NAME=db1.jp.example.com))) dc=us dc=jp cn=OracleContext cn=sales cn=db1
.
.
.
.
.
.
Each entry is uniquely identified by a
. The DN indicates exactly where the entry resides in the directory server hierarchy. The DN for db1 is dn:cn=db1,cn=OracleContext,dc=jp,dc=example,dc=com
. The DN for sales is dn:cn=sales,cn=OracleContext,dc=jp,dc=example,dc=com
. The format of a DN places the lowest component of the DIT to the left, then moves progressively up the DIT.
Each DN is made up of a sequence of relative distinguished names (RDNs). The RDN consists of an
cn
, and a value, such as db1
or sales
. The RDN for db1 is cn=db1
, and the RDN for sales is cn=sales
. The attribute and its value uniquely identify the entry.
3.2.1.1 Fully-Qualified Names for Domain Component Namespaces
For domain component namespaces, the default directory entry defined for the client must be in one of the following formats: dc[,dc][...] ou,dc[,dc][...]
In the preceding syntax, [dc] represents an optional domain component, [...] represents additional domain component entries and ou represents the organizational unit entry.
The fully-qualified name used in the connect identifier by the client must be in one of the following formats: cn.dc[.dc][...] cn[.ou]@dc[.dc][...]
In the preceding syntax, [cn] represents the Oracle Net entry.
Example 3-1 Using a Fully-Qualified Name with an Organizational Unit
Consider a directory server that contains an entry for database object sales with a DN of cn=sales,cn=OracleContext,dc=jp,dc=example,dc=com
. In this example, the client requires a connect identifier of sales.jp.example.com
.
Consider a similar entry that contains database object sales with a DN of cn=sales,cn=OracleContext,ou=mktg,dc=jp,dc=example,dc=com
.
Because domain components must be separated from organization units, the client must use the format [email protected]
. The client requires the connect identifier to be [email protected]
.
Managing Network Address Information 3-5
Using a Directory Server for Centralized Management
Figure 3-5 (page 3-6) illustrates the preceding example.
Figure 3-5 Fully-Qualified Name for Domain Component Namespaces
dc=jp, dc=example, dc=com cn=OracleContext cn=sales
Connect String=
CONNECT scott@sales.jp.example.com dc=jp, dc=example, dc=com ou=mktg
Connect String=
CONNECT scott@[email protected] cn=OracleContext cn=sales
3.2.1.2 Fully-Qualified Names for X.500 Namespaces
For X.500 namespaces, the default directory entry defined for the client must be in one of the following formats:
[ou],o
[ou],o,c
In the preceding formats, [ou] represents an optional organizational unit name, o represents the organization, and c represents the country.
The fully-qualified name the client uses as the connect identifier must be in one of the following formats: cn[.ou].o
cn[.ou].o.c
In the preceding formats, cn represents the Oracle Net entry.
For example, if the directory contains database object sales
with a DN of cn=sales,cn=OracleContext,ou=mktg,o=example,c=jp
, then the client requires a connect identifier of sales.mktg.example.jp
.
(page 3-6) illustrates this example.
Figure 3-6 Fully-Qualified Name for X.500 Namespaces
c=jp o=example
Connect String=
CONNECT scott@sales.mktg.example.jp ou=mktg cn=OracleContext cn=sales
3-6 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
3.2.1.3 Using the Relative Name of an Entry
If a client is configured with a default realm Oracle Context, then an entry can be identified by its relative name, and the service can be referred to by its common name.
A relative name can be used if the entry is in the same Oracle Context that was configured to be the default Oracle Context for the client's Oracle home.
Consider a directory server that contains an entry for a database called sales with a
DN of dn:cn=sales,cn=OracleContext,o=example,c=us
, as shown in
Figure 3-7 (page 3-7). If the client is configured with a default realm Oracle Context
of cn=OracleContext,o=example,c=us
, then the connect identifier can simply be sales
.
Figure 3-7 Relative Naming
c=us o=example cn=OracleContext
Connect String=
CONNECT scott@sales cn=sales
Note:
The
supports both full-qualified and relative naming. The
supports fully-qualified naming only when the complete
DN is used.
See Also:
•
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for additional information about how clients locate a directory
•
Oracle Database JDBC Developer's Guide
for additional information about
JDBC drivers
3.2.1.4 Using the Fully-Qualified Name of an Entry
Consider the same directory structure as shown in
Figure 3-7 (page 3-7), but with the
client's Oracle home configured with a default realm Oracle Context of cn=OracleContext,o=example,c=jp
.
Because the client is configured with a default Oracle Context that does not match the location of sales in the directory server, a connect string that uses sales does not work.
Instead, the client must specifically identify the location of sales, which can be done using one of the following ways:
• The entry's complete DN can be used in the connect string, for example:
CONNECT
username
@"cn=sales,cn=OracleContext,o=example,c=us"
Enter password:
password
Managing Network Address Information 3-7
Using a Directory Server for Centralized Management
JDBC Thin drivers support fully-qualified naming only when the complete DN is used. However, many applications do not support the use of a DN.
• The entry can be referred to by a fully-qualified DNS-style name which is mapped by the Directory Naming adapter to the full x.500 DN of the database object in the
LDAP directory, for example:
CONNECT
username
@sales.example.us
Enter password:
password
Note:
s support fully-qualified naming.
support fully-qualified naming only when the complete DN is used. See the
Oracle Database JDBC Developer's Guide
for additional information.
3.2.2 Understanding Oracle Context
In
(page 3-8), the entries db1
and sales
reside under cn=OracleContext
. This entry is a special RDN called an
entries under Oracle Context support various directory-enabled features, including directory naming.
Figure 3-8 Oracle Context in the DIT
dc=com dc=example
cn=db1
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=db1-server)
(PORT=1521))(CONNECT_DATA=
(SERVICE_NAME=db1.jp.example.com))) dc=us dc=jp cn=OracleContext cn=sales cn=db1
.
.
.
.
.
.
During directory configuration, you set the default Oracle Context. Clients use this
Oracle Context as the default location to look up connect identifiers in the directory server. With Oracle Internet Directory, an Oracle Context located at the root of the
DIT, with DN of dn:cn=OracleContext
, points to a default Oracle Context in an
. An identity management realm is a collection of identities governed by the same administrative policies. This Oracle Context is referred to as a
. Unless configured to use another Oracle
Context, clients use this realm-specific Oracle Context.
The default Oracle Context affects the connect string. For example, if a client must access the db1
and sales
entry frequently, then a reasonable default Oracle Context would be dc=jp,dc=example,dc=com
. If a client directory entry does not match the directory entry where a service is located, then the client must specify the fullyqualified name of an entry in the connect string, as described in "
Using Directory Naming (page 3-11)".
3-8 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
Note:
The RDN cn=OracleContext
does not have to be explicitly specified in the connect string.
See Also:
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for additional information about an identity management realm
3.2.3 Understanding Net Service Alias Entries
Directory naming enables you to create
entries in addition to database service and network service name entries. A network service alias is an alternative name for a network service name or database service. A network service alias entry does not have connect descriptor information. Instead, it references the location of the entry for which it is an alias. When a client requests a directory lookup of a network service alias, the directory determines that the entry is a network service alias and completes the lookup as if it is the referenced entry. For example, in
Figure 3-9 (page 3-9), a network service alias of db1alias is created for a database
service of db1. When db1alias is used to connect to a database service, as in
CONNECT
username@db1alias
, it will actually resolve to and use the connect descriptor information for db1.
Figure 3-9 Net Service Alias db1alias in a Directory Server
dc=com dc=example dc=jp cn=OracleContext cn=db1alias
(Net Service Alias Entry) cn=db1
There are several uses for network service aliases. As shown in Figure 3-9
(page 3-9), a network service alias can be useful as a way for clients to refer to a network service name by another name. Another use is to have a network service alias in one Oracle
Context for a database service or network service name in a different Oracle Context.
This enables a database service or network service name to be defined once in the directory server, but referred to by clients that use other Oracle Contexts.
In
Figure 3-10 (page 3-10), database service db1 resides in
dc=jp,dc=example,dc=com
. A network service alias named db1 is created in dc=us,dc=example,dc=com
. This enables clients in both Japan and the United
States to use the connect string
CONNECT username@db1
as opposed to clients in the
Unites States needing to specify
CONNECT username@db1.jp.example.com
.
Managing Network Address Information 3-9
Using a Directory Server for Centralized Management
Figure 3-10 Net Service Alias db1 in a Directory Server
dc=com dc=example dc=us cn=OracleContext dc=jp cn=OracleContext cn=db1
(Net Service Alias Entry) cn=db1
3.2.4 Who Can Add or Modify Entries in the Directory Server
The database service entries are configured during or after installation. You can then
Oracle Enterprise Manager Cloud Control
Oracle Net attributes of the database service entries. You can also use these tools to create network service name and network service alias entries.
To use these configuration tools, a DIT structure containing a
, and identity management realm must exist. The directory administrator creates this structure with Oracle Internet Directory Configuration Assistant. For some deployments, the directory administrator may need to create additional Oracle
Contexts. Additional Oracle Contexts are usually used to subdivide large sites, or separate a production environment from a test environment.
Certain tools are used by certain groups, and you must be a member of the group to use the tools, as described in the following:
• To create a database service entry with Database Configuration Assistant:
–
OracleDBCreators
group
( cn=OracleDBCreators,cn=OracleContext...
)
–
OracleContextAdmins
group
( cn=OracleContextAdmins,cn=Groups,cn=OracleContext...
)
• To create network service names or network service aliases with Oracle Net
Manager:
–
OracleNetAdmins
group
( cn=OracleNetAdmins,cn=OracleContext...
)
–
OracleContextAdmins
group
The
OracleNetAdmins
group is owned by itself. Members of the
OracleNetAdmins
group have create, modify, and read access to Oracle Net objects and attributes. They can also add or delete members in the group, and add or delete groups to be owners of the
OracleNetAdmins
group.
Any member of the
OracleNetAdmins
group can add or delete other members from the
OracleNetAdmins
group. If you prefer another group to add or delete
OracleNetAdmins
members, then you can change the owner attribute of the
OracleNetAdmins
group to another group. The owner cannot be an individual user entry but must be a group entry, and the group entry is one comprised of the LDAP schema object classes
GroupOfUniqueNames
and orclPriviledgeGroup
.
3-10 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
The
OracleContextAdmins
group is a super-user group for Oracle Context.
Members of the
OracleContextAdmins
group can add all supported types of entries to Oracle Context.
The directory user that created Oracle Context is automatically added to these groups.
Other users can be added to these groups by the directory administrator.
See Also:
•
" Configuring the Directory Naming Method
(page 8-15)" for additional information about using Oracle Net Manager
•
Oracle Database Administrator's Guide
for additional information about registering a database service with Database Configuration Assistant
3.2.5 Client Connections Using Directory Naming
Most clients needing to perform name lookups in the directory server access the directory server using anonymous authentication. To perform a lookup, the directory server must allow anonymous authentication. Directory servers usually allow anonymous authentication by default, however, some directory servers, such as earlier releases of Oracle Internet Directory, require directory configuration to allow anonymous access.
To look up entries, a client must be able to find the directory server in which that entry resides. Clients locate a directory server in one of two ways:
• Dynamically using DNS. In this case, the directory server location information is stored and managed in a central domain name server. The client, at request processing time, retrieves this information from DNS.
• Statically in the directory server usage file, ldap.ora
, created by Oracle Internet
Directory Configuration Assistant and stored on the client host.
After a directory is found, clients are directed to the realm Oracle Context from the root Oracle Context.
Clients make connections to a database using connect identifiers in the same way they might use other naming methods. A connect identifier can be a database service, network service name, or network service alias. These can be referred to by their common names (relative name) if the default Oracle Context is where the entity resides. If not, then the connect identifier needs a fully-qualified name or distinguished name.
See Also:
•
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
• Microsoft Active Directory documentation
3.2.6 Considerations When Using Directory Servers
The following considerations should be reviewed when using directory servers:
Managing Network Address Information 3-11
Using a Directory Server for Centralized Management
•
Performance Considerations (page 3-12)
•
Security Considerations (page 3-12)
•
3.2.6.1 Performance Considerations
Connect identifiers are stored in a directory server for all clients to access. Depending on the number of clients, there can be a significant load on a directory server.
During a connect identifier lookup, a name is searched under a specific Oracle
Context. Users expect relatively quick performance so the database connect time is not affected. Because of the scope of the lookup, users may begin to notice slow connect times if lookups take more than one second.
You can resolve performance problems by changing the network topology or implementing replication.
See Also:
Directory server vendor documentation for details on resolving performance issues
3.2.6.2 Security Considerations
Administrative clients can create and modify entries in the directory server, so security is essential. This section contains the following security-related topics:
•
(page 3-12)
•
(page 3-13)
3.2.6.2.1 Authentication Methods
Clients use different methods of authentication depending upon the task that is to be performed.
• Clients that perform lookups for information in the directory server typically use anonymous authentication. In Oracle Database 12c, it is possible to configure clients to authenticate their LDAP bind during name lookup. Sites that need to protect their network service data or disable anonymous binds to the directory must configure their clients to use wallets to authenticate during name lookup.
These clients require setting the following two parameters in the sqlnet.ora
file: names.ldap_authenticate_bind = TRUE wallet_location =
location_value
• Clients that administer the directory server entries authenticate with the directory server. Database Configuration Assistant or Oracle Net Manager can be used to add or modify the entries. Only authenticated users with proper privileges can modify entries. Use one of the following authentication methods:
– Simple Authentication
The client identifies itself to the directory server by means of a DN and a password. The server verifies that the DN and password sent by the client matches the DN and password stored in the directory server.
3-12 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
– Strong Authentication
The client identifies itself to the directory server by means of a public-key encryption available with Secure Sockets Layer (SSL). In public-key encryption, the sender of a message encrypts the message with the public key of the recipient. Upon delivery, the recipient decrypts the message using the recipient's private key.
3.2.6.2.2 Access Control Lists
Authentication is used with access control lists (ACLs) to determine whether clients can read, modify, or add information in the directory server. ACLs specify the following:
• The entries that the user can access.
• The authentication method used to access the entry.
• The access rights, or what the user can do with the object, such as read or write.
ACLs are established for a group of users. During Oracle Context creation, the
OracleDBCreators
,
OracleNetAdmins
, and
OracleContextAdmins
groups are created.
The user who creates Oracle Context using Oracle Net Configuration Assistant is automatically added as the first member of these groups.
(page 3-13) describes ACL requirements for these groups, anonymous users, and their relation to Oracle Net entries in the directory server.
Table 3-2 ACL Requirements for User Groups
Group
Anonymous users
OracleContextAdmins group users
OracleDBCreators group users
ACL Requirements
All Oracle Net attributes and objects in the directory server have read access for the anonymous user. Read access of these objects for anonymous is also applied to Oracle Context. This enables anonymous users to browse directory naming entries contained within the cn=OracleContext
RDN. This does not include objects used for enterprise user security.
Oracle Net Configuration Assistant sets up this access during client installation.
Members of
OracleContextAdmins
( cn=OracleContextAdmins,cn=Groups,cn=OracleConte xt,...
) have create, modify, and read access to all directory naming objects. Oracle Net Configuration Assistant establishes these access rights for this group during Oracle Context creation.
In addition to the Oracle Context creator, other users can be added to this group by the directory administrator using Oracle
Enterprise Manager Cloud Control.
Members of
OracleDBCreators
( cn=OracleDBCreators,cn=OracleContext,...
) have create and read access to database service objects and attributes.
Oracle Net Configuration Assistant establishes the access rights for this group during Oracle Context creation.
In addition to the Oracle Context creator, other users can be added to this group by the directory administrator with Oracle
Enterprise Manager Cloud Control.
Managing Network Address Information 3-13
Using a Directory Server for Centralized Management
Table 3-2 (Cont.) ACL Requirements for User Groups
Group
OracleNetAdmins group users
ACL Requirements
Members of
OracleNetAdmins
( cn=OracleNetAdmins,cn=OracleContext,...
) have create, modify, and read access to directory naming objects and attributes. Oracle Net Configuration Assistant establishes these access rights for this group during Oracle Context creation.
In addition to the Oracle Context creator, other users can be added to this group by the directory administrator.
Situations in which a high degree of security is desired for lookup or read-access to
Oracle Net Services name and related data, administrators can define additional readaccess control for some or all of the data. Such ACL definitions can prevent anonymous users from reading the Oracle Net Services data. If read-access to Oracle
Net Services data is restricted, then clients must use authenticated binds to do name lookups.
There are no predefined groups or procedures for the Oracle configuration tools for defining read-access restrictions on this data, so administrators must use standard object management tools from their directory system to manually create any necessary groups and ACLs.
ACLs can be added to Oracle Net Services objects using ldapmodify
and an LDIFformat file.
Example 3-2 (page 3-14) shows how to restrict all access for user,
cn=user1
:
Example 3-2 Restricting User Access with an Access Control List
dn: cn=sales,cn=oraclecontext,dc=example,dc=com replace: orclentrylevelaci orclentrylevelaci: access to attr=(*) by dn="cn=user1" (noread,nosearch,nowrite,nocompare)
The preceding example illustrates the basic form of an ACL for a single object. This approach is not necessarily the best way to define access because access definitions for objects are complex and may involve security properties which are inherited from parent nodes in the DIT. Oracle recommends that administrators refer to the documentation for their directory systems, and integrate access management for
Oracle Net Services objects into a directory-wide policy and security implementation.
For Oracle Internet Directory directories, oidadmin
has functionality to create users, groups, and also define ACLs for objects and general directory security.
3-14 Oracle Database Net Services Administrator's Guide
Using a Directory Server for Centralized Management
See Also:
• Documentation from your directory server vendor for information about how to set ACLs on directory entry
•
" Authentication Methods (page 3-12)" for information about configuring
clients to use authenticated binds for name lookup
•
" About the OracleNetAdmins Group (page 7-6)" for information about
adding users to the
OracleNetAdmins
group
•
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
3.2.6.3 Object Classes
Directories must be populated with the correct version of the Oracle schema before
Oracle Context, a database service or network service name entry can be created. The
Oracle schema defines the type of objects, called
es, that can be stored in the directory server and their attributes.
Table 3-3 (page 3-15) lists the object classes
for database service, network service name, and network service alias entries.
Table 3-3 Oracle Net Services LDAP Main Object Classes
Object Class
orclDbServer
Description
Defines the attributes for database service entries.
orclNetService
Defines the attributes for network service name entries.
orclNetServiceAlias
Defines the attributes for network service alias entries.
(page 3-15) lists the object classes used by orclDbServer
, orclNetService
, and orclNetServiceAlias
.
Table 3-4 Oracle Net Services LDAP Derived Object Classes
Object Class
orclNetAddress orclNetAddressList orclNetDescription orclNetDescriptionList
Description
Defines a listener protocol address.
Defines a list of addresses.
Specifies a connect descriptor containing the protocol address of the database and the connect information to the service.
Defines a list of connect descriptors.
These object classes use attributes that specify the contents of connect descriptors.
See Also:
Oracle Database Net Services Reference
for additional information about these object classes and their attributes
Managing Network Address Information 3-15
Using a Directory Server for Centralized Management
3.2.7 Limitations of Directory Naming Support with Microsoft Active Directory
In addition to Oracle Internet Directory, directory naming support is also provided
with the following limitations:
• Oracle provides support for Microsoft Active Directory only on Microsoft
Windows operating systems. Therefore, client computers and the database server must run on Microsoft Windows operating systems to access or create entries in
Microsoft Active Directory.
• The following features are not supported by Microsoft Active Directory:
– Multiple Oracle Contexts
Microsoft Active Directory can support only one Oracle Context.
– Net service aliases
You cannot create network service aliases in Microsoft Active Directory.
However, you can create network service names.
See Also:
Microsoft Active Directory documentation for Microsoft-specific information
3-16 Oracle Database Net Services Administrator's Guide
4
Understanding the Communication Layers
The primary function of Oracle Net is to establish and maintain connections between a client application and an Oracle database server. Oracle Net is comprised of several communication layers that enable clients and database servers to share, modify, and manipulate data.
•
Understanding Oracle Net Stack Communication for Client/Server Applications
(page 4-1)
•
Using Oracle Net Stack Communication for Java Applications
(page 4-5)
•
Using Oracle Net Stack Communication for Web Clients (page 4-6)
•
Understanding Oracle Protocol Support Layer (page 4-7)
See Also:
Introducing Oracle Net Services
(page 1-1) for an introductory overview of
Oracle Net architecture
4.1 Understanding Oracle Net Stack Communication for Client/Server
Applications
A database server is the Oracle software managing a database, and a client is an application that requests information from the server. The way the client and server communicate is known as the client/server stack.
Information passed from a client application sent by the client communication stack across a network protocol is received by a similar communication stack on the database server side. The process flow on the database server side is the reverse of the process flow on the client side, with information ascending through the communication layers.
Figure 4-1 (page 4-2) illustrates the various layers on the client and on the database
server after a connection has been established.
Understanding the Communication Layers 4-1
Understanding Oracle Net Stack Communication for Client/Server Applications
Figure 4-1 Layers Used in a Client/Server Application Connection
Oracle
Net
Client
Client
Application
(uses OCI)
Presentation -
TTC
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Transport Protocol
TCP/IP, TCP/IP with SSL, SDP and Named
Pipes
Naming Methods
Security Services
Database Server
RDBMS
(uses OPI)
Presentation -
TTC
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Transport Protocol
TCP/IP, TCP/IP with SSL, SDP and Named
Pipes
Oracle
Net
This communication architecture is based on the
model. In the OSI model, communication between separate computers occurs in a stack-like fashion with information passing from one node to the other through several layers of code, including:
1.
Physical layer
2.
3.
4.
Data link layer
Network layer
Transport layer
5.
6.
Session layer
Presentation layer
7.
Application layer
Figure 4-2 (page 4-3) shows how Oracle Net software consisting of the Oracle Net
foundation layer and Oracle Protocol Support fits into the session layer of the OSI model.
4-2 Oracle Database Net Services Administrator's Guide
Understanding Oracle Net Stack Communication for Client/Server Applications
Figure 4-2 OSI Communication Layers
Client
Application
Layer
Presentation
Layer (TTC)
Session Layer
(Oracle Net)
Transport Layer
Network Layer
Data Link Layer
Physical Layer
Network Connection
Database Server
RDBMS
Presentation
Layer (TTC)
Session Layer
(Oracle Net)
Transport Layer
Network Layer
Data Link Layer
Physical Layer
illustration: release: caption: date: platform:
net81100
9
OSI Communication Layers
12/18/00 pc
See Also:
For additional information about the OSI stack, go to http://www.ietf.org
This section contains the following topics:
Understanding the Communication Layers 4-3
Understanding Oracle Net Stack Communication for Client/Server Applications
•
About the Client Communication Stack
(page 4-4)
•
About the Server Communication Stack
(page 4-5)
4.1.1 About the Client Communication Stack
The client communication stack includes the following:
•
(page 4-4)
•
•
(page 4-4)
•
(page 4-5)
4.1.1.1 Client Application Layer
During a session with the database, the client uses
interact with the database server. OCI is a software component that provides an interface between the application and SQL.
See Also:
Oracle Call Interface Programmer's Guide
4.1.1.2 Presentation Layer
Character set differences can occur if the client and database server run on different operating systems. The presentation layer resolves any differences. It is optimized for each connection to perform conversion when required.
The presentation layer used by client/server applications is
. TTC provides character set and data type conversion between different
character sets or formats on the client and database server. At the time of initial connection, TTC is responsible for evaluating differences in internal data and character set representations and determining whether conversions are required for the two computers to communicate.
4.1.1.3 Oracle Net Foundation Layer
The Oracle Net foundation layer is responsible for establishing and maintaining the connection between the client application and database server, as well as exchanging messages between them. The Oracle Net foundation layer can perform these tasks because of
Transparent Network Substrate (TNS)
technology. TNS provides a single,
common interface for all industry-standard OSI transport and network layer protocols.
TNS enables peer-to-peer application connectivity, where two or more computers can communicate with each other directly, without the need for any intermediary devices.
On the client side, the Oracle Net foundation layer receives client application requests and resolves all generic computer-level connectivity issues, such as:
• The location of the database server or destination
• How many protocols are involved in the connection
• How to handle interrupts between client and database server based on the capabilities of each
4-4 Oracle Database Net Services Administrator's Guide
Using Oracle Net Stack Communication for Java Applications
On the server side, the Oracle Net foundation layer performs the same tasks as it does on the client side. It also works with the listener to receive incoming connection requests.
In addition to establishing and maintaining connections, the Oracle Net foundation layer communicates with naming methods to resolve names and uses security services to ensure secure connections.
4.1.1.4 Oracle Protocol Support Layer
Oracle protocol support layer is positioned at the lowest layer of the Oracle Net foundation layer. It is responsible for mapping TNS functionality to industry-standard protocols used in the client/server connection. This layer supports the following network protocols:
• TCP/IP (
)
• TCP/IP with SSL
• Named Pipes
• Sockets Direct Protocol (SDP)
• Exadirect
All Oracle software in the client/server connection process requires an existing network protocol stack to establish the computer-level connection between the two computers for the transport layer. The network protocol is responsible for transporting data from the client computer to the database server computer, at which point the data is passed to the server-side Oracle protocol support layer.
See Also:
"
Understanding Oracle Protocol Support Layer
(page 4-7)" for descriptions of the protocols
4.1.2 About the Server Communication Stack
The server communication stack uses the same layers as the client stack with the exception that the database uses
Oracle Program Interface (OPI)
sent from OCI, OPI provides a response. For example, an OCI request to fetch 25 rows would elicit an OPI response to return the 25 rows after they have been fetched.
4.2 Using Oracle Net Stack Communication for Java Applications
Java Database Connectivity (JDBC) Driver
s provide Java applications access to an Oracle database. Oracle offers two JDBC drivers.
•
is a type 2 JDBC driver which is used by client/server Java
applications. The JDBC OCI driver uses a communication stack similar to a standard client/server communication stack. The JDBC OCI driver converts JDBC invocations to calls to OCI which are then sent over Oracle Net to the Oracle database server.
•
is a type 4 driver which is used by Java applets. The JDBC Thin
Driver establishes a direct connection to the Oracle database server over Java sockets. The JDBC Thin driver uses a Java implementation of the Oracle Net
Understanding the Communication Layers 4-5
Using Oracle Net Stack Communication for Web Clients foundation layer called JavaNet and a Java implementation of TTC called JavaTTC to access the database.
The following figure shows the stack communication layers used by JDBC drivers.
Figure 4-3 Layers Used for Java-Client Applications
JDBC OCI
Driver Stack
Java Client
Application
JDBC OCI Driver
(uses OCI)
Presentation -
TTC
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Transport Protocol
TCP/IP, TCP/IP with SSL, SDP and Named
Pipes
JDBC Thin
Driver Stack
Java Applet /
Application
JDBC Thin Driver
Presentation -
JavaTTC
JavaNet
TCP/IP Network
Protocol
See Also:
Oracle Database JDBC Developer's Guide
4.3 Using Oracle Net Stack Communication for Web Clients
The Oracle database server supports many other implementations for the presentation layer that can be used for web clients accessing features inside the database in addition to TTC. The listener facilitates this by supporting any presentation implementation requested by the database.
Figure 4-4 (page 4-6) shows the stack communication layers used in an HTTP or FTP
connection to
in the Oracle database instance. WebDAV connections use the same stack communication layers as HTTP and FTP.
Figure 4-4 Layers Used in Web Client Connections
Client
Web Browser
Presentation -
HTTP or FTP
Transport Protocol -
TCP/IP
Database Server
RDBMS and
Oracle XML DB
Presentation -
HTTP or FTP
TCP/IP Oracle
Protocol Support
Transport Protocol -
TCP/IP
See Also:
Oracle XML DB Developer's Guide
4-6 Oracle Database Net Services Administrator's Guide
Understanding Oracle Protocol Support Layer
4.4 Understanding Oracle Protocol Support Layer
A network protocol is responsible for transporting data from the client computer to the database server computer. This section describes the protocols used by the Oracle
Protocol Support layer of the Oracle Net communication stack. It contains the following topics:
•
(page 4-7)
•
About TCP/IP with SSL Protocol (page 4-12)
•
(page 4-12)
•
About Sockets Direct Protocol (SDP)
(page 4-12)
•
About Exadirect Protocol (page 4-12)
See Also:
Oracle Database Net Services Reference
for information about the settings for each protocol
4.4.1 About TCP/IP Protocol
TCP/IP (Transmission Control Protocol/Internet Protocol) is the standard communication protocol suite used for client/server communication over a network.
TCP is the transport protocol that manages the exchange of data between hosts. IP is a network layer protocol for packet-switched networks.
Oracle Net supports IP in two versions: IP version 4 (IPv4) and IP version 6 (IPv6).
IPv6 addresses the shortcomings of the currently used IPv4. The primary benefit of
IPv6 is a large address space derived from the use of 128-bit addresses.
See Also:
http://tools.ietf.org/html/rfc2460
for the IPv6 specification
4.4.1.1 IPv6 Address Notation
Oracle Database supports the standard IPv6 address notations specified by RFC 2732.
A 128-bit IP address is generally represented as 8 groups of 4 hexadecimal digits, with the colon (
:
) symbol as the group separator. For example, the following address is in a valid IPv6 format:
2001:0db8:0000:0000:0000:0000:200C:417A
Each hexadecimal digit in the address represents 4 bits, so each group in the address represents 16 bits. The following addresses represent the first and last hosts in the
2001:0db8:0000:0000
subnet:
2001:0db8:0000:0000
:0000:0000:0000:0000
2001:0db8:0000:0000
:FFFF:FFFF:FFFF:FFFF
In shorthand notation, consecutive zero fields can be compressed with a double colon
(
::
) separator, as shown in the following equivalent notations:
Understanding the Communication Layers 4-7
Understanding Oracle Protocol Support Layer
2001:0db8:0:0::200C:417A
2001:0db8::200C:417A
2001:DB8::200C:417A
See Also:
• http://www.ietf.org/rfc/rfc2732.txt
for RFC 2732, and information about notational representation
• http://www.ietf.org/rfc/rfc3513.txt
for RFC 3513, and information about proper IPv6 addressing
4.4.1.1.1 CIDR Notation
Classless Inter-Domain Routing (CIDR) is a method of grouping IP addresses into subnets that are independent of the value of the addresses. Classless routing was designed to overcome the exhaustion of address space in the IP class system and the unmanageable growth in the size of routing tables.
CIDR denotes a network by the first address in the network and the size in bits of the network prefix in decimal, separated with a slash (
/
). For example,
2001:0db8::/32 indicates that the first 32 bits of the address identify the network, whereas the remaining bits identify the hosts in the network.
CIDR uses an analogous notation for IPv4 address. For example, in the notation
192.0.2.0/24
the first 24 bits of the address represent the network prefix. The
DBMS_NETWORK_ACL_ADMIN
package, which provides an API to manage access control lists, supports CIDR notation for both IPv6 and IPv4 addresses and subnets.
See Also:
•
Oracle Database PL/SQL Packages and Types Reference
to learn about
DBMS_NETWORK_ACL_ADMIN
• http://tools.ietf.org/html/rfc4632
for RFC 4632
4.4.1.1.2 IPv6 Addresses in URLs
In URLs, IPv6 addresses are enclosed by the left bracket (
[
) and right bracket (
]
) characters. For example, the IPv6 address
[2001:0db8:0:0:8:800:200C:417A] forms part of the following URLs: http://[2001:0db8:0:0:8:800:200C:417A] http://[2001:0db8:0:0:8:800:200C:417A]:80/index.html
4.4.1.1.3 IPv4-Mapped Addresses
IPv4-mapped addresses are a subclass of IPv6 addresses in which the following conditions are true:
• The first 80 bits are set to 0 in the standard IPv6 notation
• The second 16 bits are set to 1 in the standard IPv6 notation
• The last 32 bits are in IPv4 notation
4-8 Oracle Database Net Services Administrator's Guide
Understanding Oracle Protocol Support Layer
An IPv4-mapped address can represent the addresses of IPv4-only nodes as IPv6 addresses.
Example 4-1 (page 4-9) shows the same IP address in different notations. The first
address uses standard IPv6 notation. The second address is an IPv4-mapped address in which the last 32 bits use dotted-decimal IPv4 notation. The last address uses a shorthand notation to compress the consecutive zero fields.
Example 4-1 IPv4-Mapped Address
0000:0000:0000:0000:0000:FFFF:C0A8:0226
0000:0000:0000:0000:0000:FFFF:192.0.2.38
::FFFF:192.0.2.38
See Also:
http://tools.ietf.org/html/rfc4942
for security consideration relating to the use of IPv4-mapped addresses
4.4.1.2 IPv6 Interface and Address Configurations
A host may have different IPv4 and IPv6 interface configurations. The following configurations are possible for a host:
• Only an IPv4 interface, in which case the host is an IPv4-only host.
• Only an IPv6 interface, in which case the host is an IPv6-only host.
• Both an IPv4 and IPv6 interface, in which case the host is a dual-stack host.
A single host may also use different types of IP address. For example, a domain name server may associate a dual-stack host both by an IPv4 and an IPv6 address or only an
IPv6 address. The IP address configurations that are not supported are the following:
• An IPv4-only host cannot use an IPv6 address.
• An IPv6-only host cannot use an IPv4 address.
Figure 4-5 (page 4-10) shows possible host and interface configurations. The dual-
stack host in the center of the diagram can communicate with IPv4 hosts over IPv4 and with IPv6 hosts over IPv6.
Understanding the Communication Layers 4-9
Understanding Oracle Protocol Support Layer
Figure 4-5 Supported Host and Interface Configurations
Host
Interface
IPv4
IPv4 Address
192.0.2.5
IPv4 IPv6
192.0.2.4
IPv6
IPv6 Address
2001:DB8::417B 2001:DB8::417A
4.4.1.3 IPv6 Network Connectivity
The network connectivity of a host refers to its ability to communicate with another host over a network. For example, if a dual-stack client must communicate with an
IPv6-only server, then the network and router must make end-to-end communication between these hosts possible.
A client or server host is IPv6-capable if it meets the following criteria:
• It has a configured IPv6 interface.
• It can connect to other hosts using the IPv6 protocol.
The IPv6 capability of a host is partially dependent on the network and partially
dependent on its interface and address configuration. Figure 4-6
(page 4-11) shows the possibilities for connectivity in a client/server network. For example, an IPv4-only host can connect to either an IPv4-only or dual-stack server, but not an IPv6-only server. Both dedicated and shared server modes are supported.
4-10 Oracle Database Net Services Administrator's Guide
Understanding Oracle Protocol Support Layer
Figure 4-6 Client/Server Connectivity
Clients Servers
IPv4 Only IPv4 Only
IPv4 / IPv6 IPv4 / IPv6
IPv6 Only IPv6 Only
(page 4-11) summarizes the IP protocols used for client/server connectivity with different host and network configurations.
Table 4-1 Supported Host and Network Configurations
Client
IPv4-Only Client
Dual-Stack Client
IPv6-Only Client
IPv4-Only Server
Supported (v4)
Supported (v4)
Not Supported
Dual-Stack Server
Supported (v4)
Supported (v4, v6)
Supported (v6)
IPv6-Only Server
Not Supported
Supported (v6)
Supported
See Also:
•
" About IPv6 Addresses in Connect Descriptors
(page 2-6)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
" Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
(page 10-8)"
4.4.1.4 IPv6 Support in Oracle Database 12c
Components in this release of Oracle Database 12c support IPv6 in the configurations
described in " IPv6 Network Connectivity
(page 4-10)", with the following exception:
• Oracle Clusterware for private and ASM networks
Understanding the Communication Layers 4-11
Understanding Oracle Protocol Support Layer
See Also:
Oracle Clusterware Administration and Deployment Guide
4.4.2 About TCP/IP with SSL Protocol
The TCP/IP with
protocol enables an Oracle application on a client to communicate with remote databases through TCP/IP and SSL. SSL stores authentication data, such as certificates and private keys, in an Oracle Wallet.
When the client initiates a connection to the database server, SSL performs a handshake between the two using the certificate. During the handshake, the following processes occur:
• The client and database server negotiate a cipher suite made up a set of authentication, encryption, and data integrity types to apply to the messages they exchange.
• Depending on its configuration, the database server sends its certificate to the client in a message encrypted with the client's public key. The database server may also send a request for the client's certificate in the same message. The client decrypts this message by using its own private key, then verifies that the database server's certificate bears the certificate authority's signature.
• If required, the client may send the user's certificate to the database server. The certificate ensures that the user's information is correct and that the public key actually belongs to that user.
The database checks the user certificate to verify that it bears the signature of the certificate authority.
See Also:
Oracle Database Security Guide
4.4.3 About Named Pipes Protocol
Named Pipes is specifically designed for Microsoft Windows LAN environments. The
is a high-level interface providing interprocess
communications between clients and database servers using distributed applications.
One server-side process creates a named pipe, and the client-side process opens it by name. What one side writes, the other can read.
If a remote Oracle database is running on a host system that supports network communication using Named Pipes, then Oracle Net enables applications on a client to communicate with the Oracle database using Named Pipes.
4.4.4 About Sockets Direct Protocol (SDP)
The Sockets Direct Protocol (SDP) is an industry-standard wire protocol between
InfiniBand network peers. When used over an InfiniBand network, SDP reduces
TCP/IP overhead by eliminating intermediate replication of data and transferring most of the messaging burden away from the CPU and onto the network hardware.
4.4.5 About Exadirect Protocol
4-12 Oracle Database Net Services Administrator's Guide
Understanding Oracle Protocol Support Layer
The Exadirect protocol is an innovative protocol for low overhead database access.
Use the new transport to improve latency and throughput by leveraging Remote
Direct Memory Access (RDMA) in an InfiniBand environment.
Exadirect protocol uses TCP for control communication and IB RC transport for data.
The Exadirect protocol adapter is supported only on Oracle Linux in this release.
Understanding the Communication Layers 4-13
Understanding Oracle Protocol Support Layer
4-14 Net Services Administrator's Guide
5
Understanding Oracle Net Architecture
The Oracle Net listener is an application positioned on top of the Oracle Net foundation layer. The database receives an initial connection from a client application through the listener.
The listener brokers client requests, handing off the requests to the Oracle database server. Every time a client requests a network session with a database, the listener receives the initial request.
Figure 5-1 (page 5-1) illustrates the various layers on the client and database during
an initial connection. As shown in the diagram, the listener is at the top layer of the server-side network stack.
Figure 5-1 Layers Used in an Initial Connection
Client
Client Application
(uses OCI)
Presentation - TTC
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Transport Protocol -
TCP/IP, TCP/IP with SSL, SDP and Named
Pipes
Database Server
Listener RDBMS
Oracle Net
Foundation
Layer
Oracle Protocol
Support
Transport Protocol -
TCP/IP, TCP/IP with SSL, SDP and Named
Pipes
•
About Service Registration (page 5-1)
•
About the Listener and Connection Requests (page 5-2)
•
About Oracle Restart (page 5-3)
•
About Blocked Connection Requests
(page 5-4)
•
Understanding Database Server Process Architecture (page 5-4)
•
Understanding Oracle Connection Manager Architecture (page 5-6)
•
Complete Architecture (page 5-7)
5.1 About Service Registration
The listener determines whether a database service and its service handlers are available through
process provides the listener with information about the following:
Understanding Oracle Net Architecture 5-1
About the Listener and Connection Requests
• Names of the database services provided by the database
• Name of the database
associated with the services and its current and maximum load
•
including their type, protocol addresses, and current and maximum load
The preceding information enables the listener to direct a client request appropriately.
Figure 5-2 (page 5-2) shows two database instances registering information with two
listeners. The figure does not represent all the information that can be registered. For example, listening endpoints, such as the port numbers, can be dynamically registered with the listener.
Figure 5-2 Service Registration
Instance
Listener
Service names, instance names, network addresses
Instance
Listener
If the listener is not running when an instance starts, then the LREG process cannot register the service information. LREG attempts to connect to the listener periodically, but it may take up to 60 seconds before LREG registers with the listener after it has been started. To initiate service registration immediately after the listener is started, use the SQL statement
ALTER SYSTEM REGISTER
. This statement is especially useful in high availability configurations.
5.2 About the Listener and Connection Requests
Each listener is configured with one or more
listening endpoints. The protocol address defines the protocol the listener listens on and any other protocol-specific information. For example, the listener could be configured to listen at the following protocol address:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)))
The preceding example shows a TCP/IP address that specifies the host of the listener
( sales-server
) and a port number (1521).
Clients configured with a protocol address can send connection requests to the
listener. When a client request reaches the listener, it selects an appropriate
to service the request and forwards the request to the handler. A service handler is a dispatcher or a dedicated server process that acts as a connection point to a database.
5-2 Oracle Database Net Services Administrator's Guide
About Oracle Restart
Figure 5-3 (page 5-3) illustrates the role of the listener during the establishment of a
connection. The figure shows a browser making an HTTP connection and a client making a database connection.
1.
2.
3.
The browser or client send a connection request to the listener.
The listener parses the request and forwards it to the service handler for the database service requested.
The browser or client connect to the database.
Figure 5-3 Listener Architecture
3
Client
Web
Browser
HTTP
Presentation over TCP/IP
Database
1
Listener
2
Client
Database
Connection over TCP/IP
3
5.3 About Oracle Restart
Oracle Restart enhances the availability of Oracle databases in a single-instance environment. Using the Server Control (SRVCTL) utility, you can add components such as the listener to an Oracle Restart configuration. The configuration enables the listener to start automatically when the listener fails or is not running.
When using Oracle Restart, note the following:
• Use the SRVCTL utility to start and stop the listener. Do not use the listener control utility LSNRCTL.
• Each listener must have a unique name.
See Also:
•
" Managing a Listener in an Oracle Restart Configuration
(page 9-15)"
•
Oracle Database Administrator's Guide
to learn how to configure Oracle
Restart
Understanding Oracle Net Architecture 5-3
About Blocked Connection Requests
5.4 About Blocked Connection Requests
Blocked connection requests can occur when an incoming request occurs before the respective instance has been registered, or when a database is in restricted mode, such as when a shutdown of the database is in progress. If a database instance is in restricted mode, then LREG instructs the listener to block all connections to the instance. Clients attempting to connect receive one of the following errors:
• ORA-12526: TNS:listener: all appropriate instances are in restricted mode
• ORA-12527: TNS:listener: all appropriate instances are in restricted mode or blocking new connections
• ORA-12528: TNS:listener: all appropriate instances are blocking new connections
The ORA-12528 error occurs when a database instance is not yet registered with the listener.
See Also:
•
Oracle Database Error Messages
for information about these error messages
•
Oracle Database SQL Reference
for information about the
ALTER SYSTEM
REGISTER
statement
•
Oracle XML DB Developer's Guide
for information about dynamically registering HTTP, FTP, and WebDAV listening endpoints
5.5 Understanding Database Server Process Architecture
Based on the service handler type registered with the listener, the listener forwards requests to either a shared server or dedicated server process. The shared server architecture enables a database server to allow many client processes to share server processes. In a dedicated server configuration, the listener starts a separate dedicated server process for each incoming client connection request dedicated to servicing the client.
This section contains the following topics:
•
(page 5-4)
•
About Dedicated Server Processes (page 5-5)
5.5.1 About Shared Server Processes
Shared server processes are used in the shared server architecture, as shown in
Figure 5-4 (page 5-5). With shared server architectures, client processes ultimately
connect to a dispatcher. The LREG process registers the location and load of the dispatchers with the listener, enabling the listener to forward requests to the least loaded dispatcher. This registration process is not shown in the figure.
A dispatcher can support multiple client connections concurrently. Each client connection is bound to a
. A virtual circuit is a piece of shared memory
used by the dispatcher for client database connection requests and replies. The dispatcher places a virtual circuit on a common request queue when a request arrives.
5-4 Oracle Database Net Services Administrator's Guide
Understanding Database Server Process Architecture
An idle shared server picks up the virtual circuit from the request queue, services the request, and relinquishes the virtual circuit before attempting to retrieve another virtual circuit from the request queue. Shared servers place all completed requests into a dispatcher's response queue. Each dispatcher has its own response queue in the SGA
(System Global Area). This approach enables a small pool of server processes to serve a large number of clients.
Figure 5-4 Shared Server Architecture
Client
Database Server
Web
Browser
HTTP Connection over TCP/IP
Client
Web
Browser
FTP Connection over TCP/IP
Dispatcher
Virtual
Circuits
Shared
Server
Process
Dispatcher
Shared
Server
Process
Database
Client
Database Connection over TCP/IP
Shared
Server
Process
Client
Database Connection over TCP/IP
5.5.2 About Dedicated Server Processes
In a dedicated server architecture, each client process connects to a dedicated server
process. The server process is not shared by any other client. Figure 5-5 (page 5-6)
illustrates a dedicated server architecture.
LREG registers information about dedicated server processes with the listener. This enables the listener to start a dedicated server process when a client request arrives and forward the request to it.
Note:
Dedicated server architectures do not support HTTP, FTP, or WebDAV clients. Only database clients are supported.
Understanding Oracle Net Architecture 5-5
Understanding Oracle Connection Manager Architecture
Figure 5-5 Dedicated Server Architecture
Database Server
Database
Connection over TCP/IP
Dedicated
Server
Process
Client
Database
Database
Connection over TCP/IP
Dedicated
Server
Process
Client
5.6 Understanding Oracle Connection Manager Architecture
Oracle Connection Manager is a gateway through which client connection requests are sent either to the next hop or directly to the database server. Clients who relay connection requests through an Oracle Connection Manager can take advantage of the session multiplexing and access control features configured on Oracle Connection
Manager. It carries no service information until a LREG process registers its services.
Oracle Connection Manager consists of three components:
•
•
CMGW (Oracle Connection Manager Gateway)
•
CMADMIN (Oracle Connection Manager Administration)
The listener receives client connections and evaluates against a set of rules whether to deny or allow access. If it allows access, then the listener forwards a request to a gateway process, selecting the one with the fewest connections. The CMGW process, in turn, forwards the request to another Oracle Connection Manager or directly to the database server, relaying data until the connection terminates. If a connection to the server already exists, then the gateway multiplexes, or funnels, its connections through the existing connection. CMADMIN monitors the state of the gateway processes and the listener, shutting down or starting up processes as needed. In addition, it registers the location and load of the gateway processes with the listener, and it answers requests from the Oracle Connection Manager Control utility.
In
(page 5-7), the listener screens connection requests. A gateway process registers with the CMADMIN process., and the CMADMIN process registers with the listener. Finally, the listener forwards the connection requests to the gateway process.
After receiving the three valid client connections, the gateway process multiplexes them through a single network protocol connection to the database. The fourth connection is denied when it is evaluated against the set of rules.
5-6 Oracle Database Net Services Administrator's Guide
Complete Architecture
Figure 5-6 Oracle Connection Manager Architecture
Web
Browser
Client
Client
Web
Browser
Oracle Connection
Manager Computer
Listener
Listener
CMADMIN
Process
Gateway
Process
Multiple
Connections
Funneled
Database
Server
5.7 Complete Architecture
Oracle Net provides an architectural solution that allows for greater scalability in
Internet and intranet environments.
Figure 5-7 (page 5-8) shows how multiple connections to an Oracle database server
are made more scalable with Oracle Connection Manager and a shared server architecture. Oracle Connection Manager is used to offload some of the network I/O of the application web servers, and a shared server is used to serve more concurrent users.
Understanding Oracle Net Architecture 5-7
Complete Architecture
Figure 5-7 Scalable Architectural Solutions
Application
Web Servers
Web
Browser
Oracle
Connection
Manager
Database Server
Web
Browser
Web
Browser
Application
Web Servers
Dispatcher
Virtual
Circuits
Shared
Server
Process
Dispatcher
Shared
Server
Process
Web
Browser
Oracle
Connection
Manager
Shared
Server
Process
Web
Browser
Database
Web
Browser
5-8 Oracle Database Net Services Administrator's Guide
Part II
Configuration and Administration of Oracle
Net Services
Part II describes how to set up and configure Oracle Net Services.
This part contains the following chapters:
•
Quick Start to Oracle Net Services
(page 6-1)
•
Managing Oracle Net Services (page 7-1)
•
(page 8-1)
•
Configuring and Administering Oracle Net Listener (page 9-1)
•
Configuring Oracle Connection Manager (page 10-1)
•
Configuring a Shared Server Architecture (page 11-1)
•
Configuring Profiles (page 12-1)
•
Enabling Advanced Features of Oracle Net Services
(page 13-1)
•
Optimizing Performance (page 14-1)
6
Quick Start to Oracle Net Services
Help novice users set up and test a simple but common network configuration, such as one between a client application and a database over a TCP/IP network.
•
Prerequisites for Establishing Connectivity
(page 6-1)
•
Confirming Network Availability (page 6-2)
•
Starting Oracle Net Listener and the Oracle Database Server
(page 6-2)
•
Starting Oracle Connection Manager (page 6-4)
•
(page 6-5)
•
Using Easy Connect to Connect to a Database (page 6-6)
6.1 Prerequisites for Establishing Connectivity
The tasks in this chapter show a TCP/IP connection between a database server and a client computer. The following conditions are assumed about the database server and client computer:
• Database server
– The server is running on a network that can access the client
– An Oracle database is installed
– A listener is configured
– TCP/IP protocol support is installed
• Client computer
– The client computer is running on a network that can access the database server
– Oracle Client is installed
– TCP/IP protocol support is installed
In a TCP/IP network, each computer has a unique
service, such as
, can be used to map the IP address of a
computer with its host name. If a name resolution service is not used, then the mapping is typically stored in a centrally maintained file called hosts
. This file is located in the
/etc
directory on Linux and the
\windows\system32\drivers\etc directory on Microsoft Windows. For example, an entry for a database server computer named sales-server
may look like the following:
Quick Start to Oracle Net Services 6-1
Confirming Network Availability
#IP address of server host name alias
192.0.2.203 sales-server sales.us.example.com
6.2 Confirming Network Availability
Before using Oracle Net to connect a client computer to a database server, confirm that the client computer can successfully communicate with the database server computer.
Evaluating network connectivity can eliminate network-based errors.
The following procedure describes how to confirm network connectivity:
1.
Confirm that the database server computer can communicate with itself with a loopback test as follows:
a.
To confirm hardware connectivity, enter the following command at the command line: ping
ip_address
b.
In the preceding command,
ip_address
is the IP address of the database server computer, such as the following: ping 192.0.2.203
To confirm the DNS or host name is configured properly, enter the following command at the command line: ping
host_name
c.
In the preceding command,
host_name
is the host name of the server.
To test the TCP/IP setup for the server, enter the following command: ping 127.0.0.1
2.
ping6 ::1
The IP address 127.0.0.1 is the standard IPv4 address for a loopback test. The
IP address ::1 (0: 0: 0: 0: 0: 0: 0: 1) is the standard IPv6 address for a loopback test.
Verify the client computer can successfully communicate with the database server computer.
The method for verification varies according to the network protocol. For TCP/IP, you can use PING, FTP or TELNET utilities.
If the client computer cannot reach the server, then verify that the network cabling and network interface cards are correctly connected. Contact your network administrator to correct these problems.
6.3 Starting Oracle Net Listener and the Oracle Database Server
Oracle Net Listener and the Oracle Database server must be running in order for the database server to receive connections. The following procedure describes how to start
Oracle Net Listener:
1.
Start the listener with the Listener Control utility. From the command line, enter the following:
6-2 Oracle Database Net Services Administrator's Guide
Starting Oracle Net Listener and the Oracle Database Server
2.
lsnrctl
LSNRCTL> START [
listener_name
]
In the preceding command, listener_name is the name of the listener defined in the listener.ora
file. It is not necessary to identify the listener if you are using the default name
LISTENER
.
A status message indicating that the listener has successfully started displays.
Start the database as follows:
a.
Start SQL*Plus without connecting to the database using the following command:
SQLPLUS /nolog
b.
Connect to the database as SYSDBA using the following command:
SQL> CONNECT
username
as sysdba
You will be prompted to enter a password.
Note:
For simplicity, this example does not perform the password management techniques that a deployed system normally uses. In a production environment, follow the Oracle Database password management guidelines, and disable any sample accounts. See Oracle Database Security Guide for password management guidelines and other security recommendations.
c.
Start the database using the following command:
SQL> STARTUP
database_name
In the preceding command, database_name is the name of the database.
See Also:
Oracle Database Administrator's Guide
for additional information about starting the database
3.
Confirm that database
with the listener has completed using the Listener Control utility and the following command:
LSNRCTL> SERVICES [
listener_name
]
The
SERVICES
command lists the services supported by the database, along with
. If the database service registration is not
listed, then enter the following SQL command:
SQL> ALTER SYSTEM REGISTER;
See Also:
"
Monitoring Services of a Listener
(page 9-18)" for additional information about the
SERVICES
command
Quick Start to Oracle Net Services 6-3
Starting Oracle Connection Manager
6.4 Starting Oracle Connection Manager
If Oracle Connection Manager is installed, then start Oracle Connection Manager as follows:
1.
Start the Oracle Connection Manager Control utility (CMCTL) using the following commands: cmctl
CMCTL> ADMINISTER [
instance_name
]
In the preceding command, instance_name is the name of Oracle Connection
Manager to administer. You can determine the name by viewing the cman.ora
file. The file is located on the Oracle Connection Manager computer in the
ORACLE_HOME/network/admin
directory.
Oracle Connection Manager displays a status message indicating the name of the instance, and informs you that the instance has not yet been started.
Note:
If you do not provide an instance name as an argument, then provide Oracle
Connection Manager with a fully qualified host name. This is the default.
After you issue the
ADMINISTER
command, CMCTL displays the instance name as follows:
CMAN_
fully_qualified_host_name
2.
Start Oracle Connection Manager that you have chosen to administer using the following command: cmctl> STARTUP
3.
Oracle Connection Manager confirms that the instance has been started, and provides status for the instance.
Exit from the Oracle Connection Manager Control utility using the following command: cmctl> EXIT
Note:
On Microsoft Windows, Oracle Connection Manager can also be started through the Control Panel, as follows:
1.
2.
3.
Select Services in the Control Panel.
Select the
OracleHOME_NAMECMan
service, and then click Start.
In the Services window, click Close.
6-4 Oracle Database Net Services Administrator's Guide
Connecting to the Database
6.5 Connecting to the Database
There are several methods to connect to an Oracle database. Table 6-1
(page 6-5) lists syntax to connect to a database.
Table 6-1 Connecting to a Database
Connection Syntax Type of
Connection
From the command line
The general form of connecting an application to a database server from the command line is:
tool username@connect_identifier
You will be prompted to enter your password which will be encrypted.
For example:
SQLPLUS system@sales
Enter password: password
Description
Most Oracle tools can use the operating system command line to connect, and some provide alternatives.
From a login screen
From a 3GL application
username@connect_identifier
Some tools provide a login screen as an alternative form to log in. A user can log in to a database server by identifying both the user name and connect identifier in the user name field of the tool login screen, and entering the password in the password field.
exec sql connect :username identified by :password
In the preceding connection request, :username and :password are 3GL variables that can be set within the program either statically or by prompting the user.
When connecting to a database server, the value of the :username variable is in the form:
username@net_service_name
Applications written in 3GL, such as OCI and pre-compilers, are used by middle-tier and database application developers for direct database access from a client program.
The :password variable contains the password for the database account to which you are connecting.
Quick Start to Oracle Net Services 6-5
Using Easy Connect to Connect to a Database
Table 6-1 (Cont.) Connecting to a Database
Connection Syntax Type of
Connection
From within
SQL*Plus
SQLPLUS /nolog
SQL> CONNECT username@net_service_name
For example:
SQLPLUS /nolog
SQL> CONNECT scott@serverx
Enter password: password
In the preceding commands, username and
password
are the database user and password, and net_service_name is the network service name.
Description
Some Oracle tools have commands for database connections to allow an alternative user name to be specified without leaving the tool.
Other Oracle tools use slightly different methods specific to their function or interface.
For example, Oracle CDE tools use login buttons with fields for the user name, password, and remote database ID.
6.6 Using Easy Connect to Connect to a Database
After network connectivity has been verified as described in " Confirming Network
(page 6-2)", you can use the Easy Connect naming method to connect to the database. This naming method provides out-of-the-box TCP/IP connectivity to databases. It extends the functionality of the
method by enabling clients to connect to a database server with an optional port and service name in addition to the host name of the database. The following is the syntax to connect using Easy
Connect:
CONNECT
username
/
password
@
host
[:
port
][/
service_name
][:
server
][/
instance_name
]
Note:
In Oracle Call Interface documentation, server is referred to as connect_type
.
If Oracle Database server installation was performed in Typical mode, then the default service name used by the Oracle instance is the database name, and the following Easy
Connect syntax can be used to connect to that instance:
SQLPLUS /nolog
SQL> CONNECT
username
@"
host
/
db_name"
SQL> Enter password:
password
Note:
As of Oracle Database 10g, Oracle Database does not support the use of Oracle
Names. Oracle Database 12c clients and databases cannot use Oracle Names, including those from an LDAP proxy, to resolve naming. Oracle9i clients can still use Oracle Names to resolve naming for an Oracle Database 12c database.
However, customers are strongly encouraged to migrate to LDAP to take advantage of the new features of Oracle Database 12c.
6-6 Oracle Database Net Services Administrator's Guide
Using Easy Connect to Connect to a Database
See Also:
"
Understanding the Easy Connect Naming Method
(page 8-1)" for additional information about this method
Quick Start to Oracle Net Services 6-7
Using Easy Connect to Connect to a Database
6-8 Net Services Administrator's Guide
7
Managing Oracle Net Services
Know about the various administration tools of Oracle Net Services. This involves the
main administration applications,
Oracle Enterprise Manager Cloud Control
. Also, know about the command-line control utilities.
•
Using the User Interface Tools (page 7-1)
•
About the OracleNetAdmins Group
(page 7-6)
•
Using Listener Control Utility to Administer the Listener (page 7-8)
•
Performing Common Network Tasks (page 7-8)
7.1 Using the User Interface Tools
Oracle Net Services provides tools to help you perform configuration and administrative tasks. This section contains the following topics:
•
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net Services
(page 7-1)
•
Using Oracle Net Manager to Configure Oracle Net Services
(page 7-2)
•
Deciding When to Use Oracle Enterprise Manager Cloud Control and Oracle Net
(page 7-4)
•
Using Oracle Net Configuration Assistant to Configure Network Components
(page 7-5)
7.1.1 Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net Services
Oracle Enterprise Manager Cloud Control enables you to configure Oracle Net
Services for any Oracle home across multiple file systems. It also provides common administration functions for listeners. Oracle Enterprise Manager Cloud Control provides an integrated environment for configuring and managing Oracle Net
Services.
You can use Oracle Enterprise Manager Cloud Control to configure and administer the following from multiple Oracle homes:
• Listeners: Configure listeners to receive client connections.
• Naming: Define
identify the network location of a service. Oracle Net Manager supports configuration of connect descriptors in local tnsnames.ora
files or a centralized directory service.
• File location: Specify the file location of the Oracle Net configuration files.
Managing Oracle Net Services 7-1
Using the User Interface Tools
See Also:
Oracle Enterprise Manager Cloud Control documentation set and online help for information about using Oracle Enterprise Manager Cloud Control
7.1.1.1 Accessing the Net Services Administration Page
The following procedure describes how to access the Net Services Administration page using Oracle Enterprise Manager Cloud Control:
1.
2.
3.
From the Login to Database page, enter the database credentials, and then click
Login
.
The Select Enterprise Manager Home page appears.
Select All Targets from the Targets menu.
Select Listener from the Refine Search list.
4.
Select the listener by double-clicking on the listener name.
5.
Select Net Services Administration from the Oracle Listener menu.
The Net Services Administration page appears.
From the Net Services Administration page, you can administer the listeners, naming methods, preferences, and so on. The administration procedures are described in other chapters of this book.
7.1.2 Using Oracle Net Manager to Configure Oracle Net Services
Oracle Net Manager enables you to configure Oracle Net Services for an Oracle home on a local client or server host.
You can use Oracle Net Manager to configure the following network components:
• Listeners: Create and configure listeners to receive client connections.
• Naming: Define connect identifiers and map them to connect descriptors to identify the network location and identification of a service. Oracle Net Manager supports configuration of connect descriptors in local tnsnames.ora
files or a centralized directory service.
• Naming methods: Configure the ways connect identifiers are resolved to connect descriptors.
• Profiles: Configure preferences for enabling and configuring Oracle Net features on the client or server.
This section introduces the features of Oracle Net Manager. However, the primary documentation for using Oracle Net Manager is online help. This section contains the following topics:
•
(page 7-3)
•
(page 7-3)
•
Using Oracle Net Manager Wizards (page 7-3)
7-2 Oracle Database Net Services Administrator's Guide
Using the User Interface Tools
7.1.2.1 Starting Oracle Net Manager
To start Oracle Net Manager, do the following
• On Linux, run netmgr
from the
ORACLE_HOME/bin
directory.
• On Microsoft Windows, select Programs from the Start menu, and then select
Oracle -
HOME_NAME
. Next, select Configuration and Migration Tools, and then Net Manager.
7.1.2.2 Navigating Oracle Net Manager
The Oracle Net Manager interface includes a toolbar and menu options, as well as property sheets for configuring network components.
The navigator pane provides a tree view of network objects and the objects they contain, organized in a folder hierarchy. You can expand and collapse the folders to monitor or manage objects such as connect identifiers, listeners, and profiles. Click an object to make changes to it.
The following are the main folders in the navigator pane:
• Local
Displays networking elements configured in local configuration files:
– Net service names in the tnsnames.ora
file
– Listeners in the listener.ora
file
– Profile in the sqlnet.ora
file
•
Directory
Displays connect identifiers configured in a directory server
7.1.2.3 Using Oracle Net Manager Wizards
The Oracle Net Manager wizards provide step-by-step guidance for tasks. The wizards simplify complex tasks by guiding you through the tasks in manageable steps. The wizards are not intended to provide all configuration options. After you have completed a task with a wizard, use the other components of Oracle Net
Manager to modify the configuration.
The following topics describe the Oracle Net Manager wizards:
•
Using the Net Service Name Wizard (page 7-3)
•
Using the Directory Server Migration Wizard (page 7-4)
7.1.2.3.1 Using the Net Service Name Wizard
The Net Service Name wizard guides you through creating a basic network service name in a directory server or a tnsnames.ora
file.
The following procedure describes how to start the Net Service Name wizard to create network service names:
1.
2.
In the navigator pane, select Directory or Local, and then select Service Naming.
Click the plus sign (+) on the toolbar, or select Create from the Edit menu.
Managing Oracle Net Services 7-3
Using the User Interface Tools
See Also:
Oracle Net Manager online help for detailed information about using the Net
Service Name wizard to create a network service name
7.1.2.3.2 Using the Directory Server Migration Wizard
If a tnsnames.ora
file already exists, then its network service names can be exported to a directory server with the Directory Server Migration wizard.
The following procedure describes how to use the Directory Server Migration wizard:
1.
Select Directory from the Command menu.
2.
Select Export Net Service Names from the Oracle Net Manager menu.
See Also:
"
Exporting Local Naming Entries to a Directory Naming Server (page 8-23)"
7.1.3 Deciding When to Use Oracle Enterprise Manager Cloud Control and Oracle Net
Manager
Much of the functionality previously available only in Oracle Net Manager has been integrated with Oracle Enterprise Manager Cloud Control. Oracle Enterprise Manager
Cloud Control provides the ability to manage configuration for multiple Oracle homes across multiple file systems. Oracle Net Manager only enables you to manage configuration for one Oracle home on a local host computer. The following are the key differences between the tools.
Oracle Enterprise Manager Cloud Control
• Configure the following features:
- Local naming ( tnsnames.ora
files)
- Directory naming
- Listeners
• Provide Oracle home support across multiple file system
• Provide the ability to search and sort local and directory naming entries
• Export directory naming entries to a tnsnames.ora
file
• Perform the following administrative tasks for a selected listener:
- Show current status
- Change status
- Change tracing level settings
- Change logging settings
- Set connect-time failover and load balancing methods when there is more than one listener
Oracle Net Manager
7-4 Oracle Database Net Services Administrator's Guide
Using the User Interface Tools
• Configure the following features:
- Local naming ( tnsnames.ora
files)
- Directory naming
- Listeners
- Profiles
• Provide Oracle home support for single host
• Set connect-time failover and load balancing methods when there is more than one listener
• Set the following options for clients and servers:
- Tracing settings
- Logging settings
- Security, authentication and access rights
- Routing
Note:
When Automatic Diagnostic Repository (ADR) is enabled, any changes to the tracing and logging settings using Oracle Enterprise Manager Cloud Control are ignored by the system.
7.1.4 Using Oracle Net Configuration Assistant to Configure Network Components
Oracle Net Configuration Assistant
configures basic network components during installation, including:
• Listener names and protocol addresses
• Naming methods the client uses to resolve connect identifiers to connect descriptors
• Net service names in a tnsnames.ora
file
• Directory server usage
Oracle Net Configuration Assistant runs automatically during software installation, as described in the Oracle Database installation guide. It can also be run after installation in standalone mode to configure naming methods, the listener, network service names in the tnsnames.ora
file, and directory server usage.
To start Oracle Net Configuration Assistant do the following:
• On Linux and UNIX, run netca
from the
ORACLE_HOME/bin
directory.
• On Microsoft Windows, select Programs from the Start menu, and then select
Oracle -
HOME_NAME. Next, select Configuration and Migration Tools, and then Oracle Net Configuration Assistant.
Managing Oracle Net Services 7-5
About the OracleNetAdmins Group
See Also:
• Oracle Net Configuration Assistant online help
•
Oracle Grid Infrastructure Installation Guide
for information on running
Oracle Net Configuration Assistant in silent mode
The following are the configuration options on the Oracle Net Configuration Assistant
Welcome page:
• Listener configuration – Create, modify, delete, or rename a listener.
• Naming Methods configuration – Configure the computer to resolve connect identifiers to connect descriptor with one or more of following naming methods:
– Local naming
– Directory naming
– Easy Connect naming
– External naming
• Local Net Service Name configuration
– Create, modify, delete, rename, or test connectivity of a connect descriptor stored in a local tnsnames.ora
file
• Directory Usage Configuration – Configure a directory server for directoryenabled features.
7.2 About the OracleNetAdmins Group
To use Oracle Net Manager, you must be a member of the
OracleNetAdmins
group or the
OracleContextAdmins
group. Oracle Net Configuration Assistant establishes these access rights for these groups during Oracle Context creation.
This section contains the following topics:
•
Adding Users To the OracleNetAdmins Group (page 7-6)
•
Removing Users From the OracleNetAdmins Group
(page 7-7)
•
Changing Ownership of the OracleNetAdmins Group (page 7-7)
7.2.1 Adding Users To the OracleNetAdmins Group
The following procedure describes how to add a user to the
OracleNetAdmins group using the ldapmodify
command:
1.
Create an
(Lightweight Directory Interchange Format) file that specifies that
you want to add a user to the
OracleNetAdmins
group.
You can use the following sample LDIF file. Use the appropriate DN for cn=OracleNetAdmins
and the user that you want to add.
dn: cn=OracleNetAdmins,cn=OracleContext,...
changetype: modify
7-6 Oracle Database Net Services Administrator's Guide
About the OracleNetAdmins Group
2.
add: uniquemember uniquemember:
DN of user being added to group
Enter the following command at the command line to refresh the file:
$ ldapmodify -h
directory_host
-p
port
-D
binddn
-q -f
ldif_file
In the preceding command, directory_host is the directory server host, port is the listening TCP/IP port for the directory server, binddn is the directory administrator or user DN, and ldif_file is the input file name. If the port is not specified, then the default port of 389 is used. The
-q
option prompts for a single bind password.
7.2.2 Removing Users From the OracleNetAdmins Group
The following procedure describes how to remove a user from the
OracleNetAdmins
group with the ldapmodify
command:
1.
Create an LDIF file that specifies that you want to delete a user to the
OracleNetAdmins
group.
You can use the following sample LDIF file. Enter the appropriate DN for cn=OracleNetAdmins
and the user that you want to delete.
2.
dn: cn=OracleNetAdmins,cn=OracleContext,...
changetype: modify delete: uniquemember uniquemember:
DN of user being deleted from group
Enter the following command to delete the user:
$ ldapmodify -h
directory_host
-p
port
-D
binddn
-q -f
ldif_file
In the preceding command, directory_host is the directory server host, port is the listening TCP/IP port for the directory server, binddn is the directory administrator or user DN, and ldif_file is the input file name. If the port is not specified, then the default port of 389 is used. The
-q
option prompts for a single bind password.
7.2.3 Changing Ownership of the OracleNetAdmins Group
The following procedure describes how to add a group as an owner of an
OracleNetAdmins
group:
1.
Create an LDIF file, as follows:
a.
Specify the group you want to add as an owner.
You can use the following sample LDIF file. Enter the appropriate DN for cn=OracleNetAdmins
and the DN of the group that you want to add.
dn: cn=OracleNetAdmins,cn=OracleContext,...
changetype: modify
add: owner
owner:
DN of group to add
For example, the following LDIF syntax changes the ownership from the
OracleNetAdmins
group to another group named
ExampleSecurityAdmins
. The group can be either inside or outside Oracle
Context.
Managing Oracle Net Services 7-7
Using Listener Control Utility to Administer the Listener
2.
b.
dn: cn=OracleNetAdmins,cn=OracleContext,...
changetype: modify
add: owner
owner: cn=ExampleSecurityAdmins
(Optional) Specify the group to delete as an owner.
dn: cn=OracleNetAdmins,cn=OracleContext,...
changetype: modify
delete: owner
owner:
DN of group to delete
Enter the following command at the command line to refresh the file:
$ ldapmodify -h
directory_host
-p
port
-D
binddn
-q -f
ldif_file
In the preceding command, directory_host is the directory server host, port is the listening TCP/IP port for the directory server, binddn is the directory administrator or user DN, and ldif_file is the input file name. If the port is not specified, then the default port of 389 is used. The
-q
option prompts for a single bind password to be entered.
7.3 Using Listener Control Utility to Administer the Listener
Oracle Net Services provides tools to help you start, stop, configure, and control each network component. The Listener Control utility enables you to administer the listener. The utility is started by the user that owns the Oracle installation, or a member of the designated group, on the same machine where the listener is running.
The basic syntax for this utility is as follows: lsnrctl
command
[
listener_name
]
For example, the following command starts a listener named lsnr
: lsnrctl START lsnr
You can also issue Listener Control utility commands at the
LSNRCTL>
program prompt. To obtain the prompt, enter lsnrctl
with no arguments at the operating system command line. When you run lsnrctl
, the utility is started, and you can enter the necessary commands from the program prompt.
For example: lsnrctl
LSNRCTL> START lsnr
See Also:
•
" Customizing Oracle Net Listener Configuration (page 9-10)" for
additional information about the listener
•
Oracle Database Net Services Reference
for additional information about the
Listener Control utility
7.4 Performing Common Network Tasks
Network configuration and administration tasks are described throughout this guide.
7-8 Oracle Database Net Services Administrator's Guide
Performing Common Network Tasks
Configuring Directory Server for Oracle Net Usage
The following are the tasks for configuring directory server for Oracle Net:
• Configuring directory server usage.
Tool used to perform the task – Oracle Internet Directory Configuration Assistant
See Also:
Oracle Fusion Middleware Administrator's Guide for Oracle Internet
Directory
• Add users to the
OracleNetAdmins
group.
Tool used to perform the task – ldapmodify
See Also:
" Who Can Add or Modify Entries in the Directory Server
(page 3-10)"
• Authenticate with the directory.
Tools used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle
Net Manager
See Also:
– Online help in Oracle Enterprise Manager Cloud Control
–
Oracle Database Enterprise User Security Administrator's Guide
• Change Oracle Context.
Tool used to perform the task – Oracle Net Manager
See Also:
Online help in Oracle Net Manager
Configuring Naming Methods
The following are the tasks for configuring naming methods:
• Configure the local naming method.
Tool used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle
Net Manager, Oracle Net Configuration Assistant
See Also:
" Configuring the Local Naming Method (page 8-7)"
• Configure the directory naming method.
Tool used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle
Net Manager
See Also:
" Configuring the Directory Naming Method (page 8-15)"
• Configure the Easy Connect naming method.
Managing Oracle Net Services 7-9
Performing Common Network Tasks
Tool used to perform the task – Oracle Net Manager
See Also:
" Understanding the Easy Connect Naming Method
(page 8-1)"
• Configure external naming methods.
Tool used to perform the task – Oracle Net Manager
See Also:
" Configuring External Naming Methods
(page 8-26)"
Migrating to Directory Naming
The following is the task for migrating to directory naming:
Export from tnsnames.ora
files.
Tools used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle Net
Manager
See Also:
" Exporting Directory Naming Entries to a tnsnames.ora File
(page 8-26)"
Configuring Profiles
The following are the tasks for configuring profiles:
• Prioritize naming methods.
Tool used to perform the task – Oracle Net Manager, Oracle Net Configuration
Assistant
See Also:
(page 12-3)"
• Configure a default domain that is automatically appended to any unqualified network service name.
Tool used to perform the task – Oracle Net Manager, Oracle Net Configuration
Assistant
See Also:
" About the Default Domain for Clients (page 12-2)"
• Route connection requests.
Tool used to perform the task – Oracle Net Manager, Oracle Net Configuration
Assistant
See Also:
" Routing Connection Requests to a Process (page 12-4)"
• Configure access control.
Tool used to perform the task – Oracle Net Manager
See Also:
" Settings for Database Access Control (page 12-5)"
7-10 Oracle Database Net Services Administrator's Guide
Performing Common Network Tasks
• Configure an authentication method.
Tool used to perform the task – Oracle Net Manager
See Also:
" Configuring Oracle Network Security
(page 12-10)"
• Configure connect request timeouts.
Tool used to perform the task – Manual configuration
See Also:
" Limiting Resource Consumption by Unauthorized Users
(page 14-10)"
Configuring Listeners
The following are the tasks for configuring listeners:
• Configure listening protocol addresses.
Tool used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle
Net Manager, Oracle Net Configuration Assistant
See Also:
" Configuring Listening Protocol Addresses
(page 9-10)"
• Configure dynamic service registration.
Tool used to perform the task – Automatic configuration
See Also:
" Configuring Dynamic Service Registration
(page 9-2)"
• Configure static service registration.
Tool used to perform the task – Oracle Enterprise Manager Cloud Control, Oracle
Net Manager
See Also:
" Understanding Static Service Registration (page 13-21)"
• Configure connect request timeouts.
Tool used to perform the task – Manual configuration
See Also:
" Limiting Resource Consumption by Unauthorized Users
(page 14-10)"
Administering Listeners
The following are the tasks for administering listeners:
• Start and stop listeners.
Tool used to perform the task – Listener Control Utility
See Also:
" Starting and Stopping a Listener (page 9-14)"
Managing Oracle Net Services 7-11
Performing Common Network Tasks
• View registered information.
Tool used to perform the task – Listener Control Utility
See Also:
" Monitoring Services of a Listener (page 9-18)"
Configuring Oracle Connection Manager
The following are the tasks for configuring Oracle Connection Manager:
• Configure session multiplexing.
Tool used to perform the task – Manual configuration
See Also:
" Enabling Session Multiplexing for Oracle Connection Manager
(page 10-8)"
• Configure access control.
Tool used to perform the task – Manual configuration
See Also:
(page 10-5)"
7-12 Oracle Database Net Services Administrator's Guide
8
Configuring Naming Methods
Find out how to configure connectivity information for client connections to the database server.
•
Understanding the Easy Connect Naming Method (page 8-1)
•
Configuring the Local Naming Method
(page 8-7)
•
Configuring the Directory Naming Method
(page 8-15)
•
Creating Multiple Default Contexts in a Directory Naming Server
(page 8-22)
•
Exporting Local Naming Entries to a Directory Naming Server
(page 8-23)
•
Exporting Directory Naming Entries to a tnsnames.ora File
(page 8-26)
•
Configuring External Naming Methods (page 8-26)
See Also:
"
(page 2-13)" for an overview of naming methods
8.1 Understanding the Easy Connect Naming Method
The Easy Connect naming method eliminates the need for service name lookup in the tnsnames.ora
files for TCP/IP environments. In fact, no naming or directory system is required when using this method.
This naming method provides out-of-the-box TCP/IP connectivity to databases. It extends the functionality of the
method by enabling clients to connect to a database server with an optional port and service name in addition to the host name of the database:
CONNECT
username
@[//]
host
[:
port
][/
service_name
][:
server
][/
instance_name
]
Enter password:
password
The connect identifier converts to the following connect descriptor:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=
host
)(PORT=
port
))
(CONNECT_DATA=
(SERVICE_NAME=
service_name
)
(SERVER=
server
)
(INSTANCE_NAME=
instance_name
)))
Configuring Naming Methods 8-1
Understanding the Easy Connect Naming Method
If the Oracle Database server installation was performed in Typical mode, then the default service name used by the Oracle instance is the database name, and the following Easy Connect syntax can be used to connect to that instance:
SQLPLUS /nolog
SQL> CONNECT
username
@
host
/
db_name
SQL> Enter password:
password
(page 8-2) lists the Easy Connect syntax elements and descriptions for each.
Table 8-1 Connect Identifier for Easy Connection Naming Method
Syntax Element
//
Description
Use
//
to specify a URL or JDBC connection.
Required for URL or JDBC connections. The connect identifier must be preceded by a double-slash (
//
). For example: scott@//sales-server
Enter password: password
Optional for SQL connections. The connect identifier can preceded by a double-slash (
//
). For example, the following connect strings are semantically equivalent:
SQL> CONNECT scott@sales-server
SQL> CONNECT scott@//sales-server host port service_name
Required. Specify the host name or IP address of the database host computer.
The host name is domain-qualified if the local operating system configuration specifies a domain.
You may use an IPv4 or IPv6 address as a value. IPv6 addresses or host names that resolve to IPv6 addresses must be enclosed in square brackets, as in
[2001:0db8:0:0::200C:417A] and
[salesdb]
.
Optional. Specify the listening port.
The default is 1521.
Optional. Specify the service name of the database.
If a user specifies a service name, then the listener connects the user to that specific database. Otherwise, the listener connects to the database specified by the
DEFAULT_SERVICE_listener_name parameter in the listener.ora
file. If DEFAULT_SERVICE_listener_name is not configured for the listener and a service name is not explicitly specified by the user as part of the Easy Connect syntax, then the listener returns an error.
8-2 Oracle Database Net Services Administrator's Guide
Understanding the Easy Connect Naming Method
Table 8-1 (Cont.) Connect Identifier for Easy Connection Naming Method
Syntax Element
server instance_name
Description
Optional. Specify the database server type to use.
This parameter instructs the listener to connect the client to a specific type of service handler.
The values for the server parameter are dedicated
, shared
, and pooled
. If server is not specified in the Easy Connect syntax, then the type of server is chosen by the listener (shared server if configured, otherwise a dedicated server is used).
Note
: In Oracle Call Interface documentation, server is referred to as connect_type
.
Optional. Identify the database instance to access.
The instance name can be obtained from the
INSTANCE_NAME parameter in the initialization parameter file.
See Also:
Oracle Database Net Services Reference
for additional information about configuring the DEFAULT_SERVICE_listener_name parameter, and the
INSTANCE_NAME initialization parameter
The connect strings in Example 8-1
(page 8-3) connect the client to database service sales.us.example.com
with a listening endpoint of 1521 on database server sales-server
.
Example 8-1 Easy Connect Strings
CONNECT scott@sales-server:1521/sales.us.example.com
CONNECT scott@//sales-server/sales.us.example.com
CONNECT scott@//sales-server.us.example.com/sales.us.example.com
After each of the connect strings in Example 8-1
(page 8-3), you must enter a password to connect to the database service.
The connect strings in Example 8-1
(page 8-3) convert into the following connect descriptor:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
8.1.1 Examples of Easy Connect Naming Method
(page 8-4) shows examples of Easy Connect naming syntax and how each string converts into a connect descriptor.
Configuring Naming Methods 8-3
Understanding the Easy Connect Naming Method
Table 8-2 Examples of Easy Connect Naming
Naming Option
Easy Connect string with host.
The host name is salesserver
.
Connect String
sales-server
Connect Descriptor
(DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=))
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=1521)))
Easy Connect string with host and port.
The host name is salesserver
, and the port is
3456
.
sales-server:3456 (DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=))
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=3456)))
Easy Connect string with host and service name.
The host name is salesserver
and the service name is sales
.
sales-server/sales
Easy Connect string with
IPv6 host address.
The host is salesserver
, the port is
80
, and the service name is sales
.
sales-server:80/sales
(DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=sales))
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=1521)))
Easy Connect string with
IPv6 address.
The IPv6 address of the host is
2001:0db8:0:0::200C:
417A
, the port is
80
, and the service name is sales
.
[2001:0db8:0:0::200C:417A]:80/sales
Square brackets are required around
IPv6 host names.
(DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=sales)
(ADDRESS=
(PROTOCOL=TCP)
(HOST=2001:0db8:0:0::200C:
417A)
(PORT=80)))
(DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=sales)
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=80)))
8-4 Oracle Database Net Services Administrator's Guide
Understanding the Easy Connect Naming Method
Table 8-2 (Cont.) Examples of Easy Connect Naming
Connect String Naming Option
Easy Connect string with host, service name, and server.
The host name is salesserver
, the service name is sales
, the server is dedicated
, and the instance name is inst1 sales-server/sales:dedicated/inst1
Connect Descriptor
(DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=sales)
(INSTANCE_NAME=inst1)
(SERVER=dedicated))
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=1521)))
Easy Connect with host and instance name.
The host name is salesserver
and the instance name is inst1
.
sales-server//inst1 (DESCRIPTION=
(CONNECT_DATA=
(SERVICE_NAME=)
(INSTANCE_NAME=inst1))
(ADDRESS=
(PROTOCOL=TCP)
(HOST=sales-server)
(PORT=1521)))
See Also:
•
" About TCP/IP Protocol (page 4-7)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
" Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
(page 10-8)"
8.1.2 Configuring Easy Connect Naming on the Client
Clients can connect to Oracle Database using Easy Connect naming if the following conditions are met:
• Oracle Net Services software is installed on the client.
• Oracle TCP/IP protocol is supported on both the client and database server.
• No features require a more advanced connect descriptor.
Easy Connect naming is not suitable for large or complex environments with advanced features, such as
require additional connect information. In these cases, another naming method is recommended.
Easy Connect naming is automatically configured at installation. Before using it, you may want to ensure that
EZCONNECT
is specified by the NAMES.DIRECTORY_PATH
parameter in the sqlnet.ora
file. This parameter specifies the order of naming methods Oracle Net can use to resolve connect identifiers to connect descriptors.
Configuring Naming Methods 8-5
Understanding the Easy Connect Naming Method
The following procedure describes how to verify that the Easy Connect naming method is configured:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
In the navigator pane, expand Local, and then select Profile.
From the list in the right pane, select Naming.
Click the Methods tab.
Verify that
EZCONNECT
is listed in the Selected Methods list. If it is not, then proceed to Step
5 (page 8-6). If it is listed, then proceed to Step 7 (page 8-6).
From the Available Methods list, select EZCONNECT, and then click the rightarrow button.
In the Selected Methods list, select EZCONNECT, and then use the Promote button to move the selection to the top of the list.
Select Save Network Configuration from the File menu.
The sqlnet.ora
file updates the NAMES.DIRECTORY_PATH parameter, listing hostname
first:
NAMES.DIRECTORY_PATH=(ezconnect, tnsnames)
8.1.3 Configuring Easy Connect Naming to Use a DNS Alias
You can optionally configure a DNS alias for the host name, as provided with the host naming method in Oracle Database 12c. With host naming, clients use a connect string that uses the following pattern:
CONNECT
username@DNS_alias
Enter password:
password
The following procedure describes how to configure a DNS alias:
1.
Ensure the database service is registered with the listener.
If the database can find the listener, then information about the database service is
dynamically registered with the listener during
service name. The listener is found if the following conditions are met:
2.
• The default listener named
LISTENER
on TCP/IP, port 1521 is running.
• The LOCAL_LISTENER parameter is set in the initialization file.
If the database cannot find the listener, then refer to "
Registration for the Listener (page 13-23)" for information about static registration.
Establish a host name resolution environment.
You can configure a mechanism such as DNS, NIS, or a centrally-maintained
TCP/IP host file,
/etc/hosts
. For example, if a service name of
8-6 Oracle Database Net Services Administrator's Guide
Configuring the Local Naming Method
3.
sales.us.example.com
for a database exists on a computer named salesserver
, then the entry in the
/etc/hosts
file would look like the following:
#IP address of server host name alias
192.0.2.35 sales-server sales.us.example.com
The domain section of the service name must match the network domain.
Connect to the database using the DNS alias.
Using the example in the previous step, the client can use sales.example.com
in the connect string:
CONNECT
username
@sales.us.example.com
Enter password:
password
If the client and server are in the same domain such as us.example.com
, then the client must enter only sales
in the connect string.
8.2 Configuring the Local Naming Method
The local naming method adds network service names to the tnsnames.ora
file.
Each network service name maps to a connect descriptor.
Example 8-2 (page 8-7) shows the network service name
sales
mapped to the connect descriptor contained in DESCRIPTION. The DESCRIPTION section contains the protocol address and identifies the destination database service. In this example, the protocol is TCP/IP and the port is 1521.
Example 8-2 Connector Descriptor with Host Name
sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
Example 8-3 (page 8-7) shows a valid
tnsnames.ora
entry to connect to a host identified with an IPv6 address and a port number of 1522.
Example 8-3 Connect Descriptor with IPv6 Address
salesdb =
( DESCRIPTION =
( ADDRESS=(PROTOCOL=tcp)(HOST=2001:0db8:1:1::200C:417A)(PORT=1522) )
( CONNECT_DATA =
(SERVICES_NAME=sales.example.com) )
)
You can configure local naming during or after installation, as described in the following sections:
•
Configuring the tnsnames.ora File During Installation (page 8-8)
•
Configuring the tnsnames.ora File After Installation
(page 8-8)
See Also:
"
(page 4-10)"
Configuring Naming Methods 8-7
Configuring the Local Naming Method
8.2.1 Configuring the tnsnames.ora File During Installation
Oracle Net Configuration Assistant
enables you to configure network service names for clients. Oracle Universal Installer launches Oracle Net Configuration Assistant after software installation. The configuration varies depending on the installation mode.
• Administrator or runtime installation: Oracle Net Configuration Assistant prompts you to configure network service names in the tnsnames.ora
file to connect to an Oracle Database service.
• Custom installation: Oracle Net Configuration Assistant prompts you to select naming methods to use. If local is selected, then Oracle Net Configuration
Assistant prompts you to configure network service names in the tnsnames.ora
file to connect to an Oracle Database service.
8.2.2 Configuring the tnsnames.ora File After Installation
You can add network service names to the tnsnames.ora
file at any time after installation. To configure the local naming method, perform the following tasks:
•
Task 1, Configure Net Services Names
(page 8-8)
•
Task 2, Configure Local Naming as the First Naming Method (page 8-13)
•
Task 3, Copy the Configuration to the Other Clients
(page 8-14)
•
Task 4, Configure the Listener (page 8-14)
•
Task 5, Connect to the Database
(page 8-14)
Note:
The underlying network connection must be operational before attempting to configure connectivity with Oracle Net.
Task 1 Configure Net Services Names
To configure the network services names, use one of the following methods:
•
Net Services Names Configuration using Oracle Enterprise Manager Cloud
•
Net Services Names Configuration using Oracle Net Manager (page 8-10)
•
Net Services Names Configuration using Oracle Net Configuration Assistant
(page 8-12)
Each method provides similar functionality. However, Oracle Net Manager has more configuration options for the sqlnet.ora
file.
•
Net Services Names Configuration using Oracle Enterprise Manager Cloud
Control
8-8 Oracle Database Net Services Administrator's Guide
Configuring the Local Naming Method
The following procedure describes how to configure network service names in the tnsnames.ora
file with Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
Select Local Naming from the Administer list, and then select the Oracle home that contains the location of the configuration files.
The Local Naming page appears. You may be prompted to log in to the database server.
Click Create Like.
The Create Net Service Name page appears.
Enter a name in the Net Service Name field.
You can qualify the network service name with the client's domain. The network service name is automatically domain qualified if the s qlnet.ora
file parameter NAMES.DEFAULT_DOMAIN is set.
See Also:
"
About the Default Domain for Clients
(page 12-2)"
6.
In the Database Information section, configure service support as follows:
a.
Enter a destination service name.
See Also:
"
About Connect Descriptors (page 2-5)" for additional information about the
service name string to use
b.
Select a database connection type.
The default setting of Database Default is recommended for the connection type. If
is configured in the initialization
parameter file, then you can select Dedicated Server to force the listener to spawn a dedicated server, bypassing shared server configuration. If shared server is configured in the initialization parameter file and you want to guarantee the connection always uses shared server, then select
Shared Server.
See Also:
"
Configuring a Shared Server Architecture (page 11-1)" for additional
information about shared server configuration
7.
In the Addresses section, configure protocol support, as follows:
Configuring Naming Methods 8-9
Configuring the Local Naming Method
a.
b.
c.
Click Add.
The Add Address page appears.
From the Protocol list, select the protocol on which the listener is configured to listen. This protocol must also be installed on the client.
Enter the appropriate parameter information for the selected protocol in the fields provided.
See Also:
Oracle Database Net Services Reference
for additional information about protocol parameter settings
d.
(Optional) In the Advanced Parameters section, specify the I/O buffer space limit for send and receive operations of sessions in the Total Send
Buffer Size and Total Receive Buffer Size fields.
See Also:
"
Configuring I/O Buffer Space (page 14-4)" for additional information about
buffer space
8.
9.
e.
Click OK.
The protocol address is added to the Addresses section.
Click OK to add the network service name.
The network service name is added to the Local Naming page.
Select connect-time failover and client load balancing option for the addresses.
10.
Click OK.
See Also:
–
" Creating a List of Listener Protocol Addresses (page 13-1)" to configure
multiple protocol addresses
–
" About the Advanced Connect Data Parameters (page 13-6)" to
configure additional CONNECT_DATA options
•
Net Services Names Configuration using Oracle Net Manager
The following procedure describes how to configure network service names in the tnsnames.ora
file with Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
8-10 Oracle Database Net Services Administrator's Guide
Configuring the Local Naming Method
2.
3.
4.
In the navigator pane, select Service Naming from Local.
Click the plus sign (+) from the toolbar, or select Create from the Edit menu.
The Welcome page of the Net Service Name wizard appears.
Enter a name in the Net Service Name field.
You can qualify the network service name with the client's domain. The network service name is automatically domain qualified if the s qlnet.ora
file parameter NAMES.DEFAULT_DOMAIN is set.
See Also:
"
About the Default Domain for Clients
(page 12-2)"
5.
6.
7.
8.
Click Next.
The Protocol page appears.
Select the protocol on which the listener is configured to listen. The protocol must also be installed on the client.
Click Next.
The Protocol Settings page appears.
Enter the appropriate parameter information for the selected protocol in the fields provided.
See Also:
Oracle Database Net Services Reference
for additional information about protocol parameter settings
9.
Click Next.
The Service page appears.
10.
Enter a destination service name, and optionally, select a database connection type.
Oracle recommends that you use the default setting of Database Default for the connection type. If dedicated server is configured in the initialization parameter file, then you can select Dedicated Server to force the listener to spawn a dedicated server, bypassing shared server configuration. If shared server is configured in the initialization parameter file and you want to guarantee the connection always uses shared server, then select Shared
Server.
Configuring Naming Methods 8-11
Configuring the Local Naming Method
See Also:
–
Configuring a Shared Server Architecture (page 11-1) for additional
information about shared server configuration
–
" About Connect Descriptors (page 2-5)" for additional information about
the service name string to use
11.
Click Next.
The Test page appears.
12.
Click Test to verify that the network service name works, or click Finish to dismiss the Net Service Name wizard.
If you click Test, then Oracle Net connects to the database server by using the connect descriptor information you configured. Therefore, the listener and database must be running for a successful test. If they are not, then see
" Starting Oracle Net Listener and the Oracle Database Server (page 6-2)" to
start components before testing. During testing, a Connection Test dialog box appears, providing status and test results. A successful test results in the following message:
The connection test was successful.
If the test was successful, then click Close to close the Connect Test dialog box, and proceed to Step 13.
If the test was not successful, then do the following:
a.
Ensure that the database and listener are running, and then click Test.
b.
Click Change Login to change the user name and password for the connection, and then click Test.
13.
Click Finish to close the Net Service Name wizard.
14.
Select Save Network Configuration from the File menu.
See Also:
–
" Creating a List of Listener Protocol Addresses (page 13-1)" to configure
multiple protocol addresses
–
" About the Advanced Connect Data Parameters (page 13-6)" to
configure additional CONNECT_DATA options
•
Net Services Names Configuration using Oracle Net Configuration Assistant
The following procedure describes how to configure network service names in the tnsnames.ora
file with Oracle Net Configuration Assistant:
1.
Start Oracle Net Configuration Assistant.
8-12 Oracle Database Net Services Administrator's Guide
Configuring the Local Naming Method
See Also:
"
Using Oracle Net Configuration Assistant to Configure Network
(page 7-5)"
2.
3.
4.
5.
6.
The Welcome page appears.
Select Local Net Service Name Configuration, and then click Next.
The Net Service Name Configuration page appears.
Click Add, and then click Next.
The Service Name Configuration page appears.
Enter a service name in the Service Name field.
Click Next.
Follow the prompts in the wizard and online help to complete network service name creation.
Task 2 Configure Local Naming as the First Naming Method
Configure local naming as the first method specified in the
NAMES.DIRECTORY_PATH parameter in the sqlnet.ora
file. This parameter specifies the order of naming methods Oracle Net uses to resolve connect identifiers to connect descriptors.
To configure the local naming method as the first naming method, use one of the following methods:
•
Local Naming Configuration using Oracle Enterprise Manager Cloud Control
(page 8-13)
•
Local Naming Configuration using Oracle Net Manager
(page 8-14)
Each method provides the same functionality.
Local Naming Configuration using Oracle Enterprise Manager Cloud Control
The following procedure describes how to specify local naming as the first naming method using Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
Select Network Profile from the Administer list.
Click Go.
Select Naming Methods.
Select TNSNAMES from the Available Methods list.
Configuring Naming Methods 8-13
Configuring the Local Naming Method
6.
7.
Click Move to move the selection to the Selected Methods list.
Use the Promote button to move TNSNAMES to the top of the list.
8.
Click OK.
Local Naming Configuration using Oracle Net Manager
The following procedure describes how to specify local naming as the first naming method using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Naming.
Click the Methods tab.
From the Available Methods list, select TNSNAMES, and then click the rightarrow button.
From the Selected Methods list, select TNSNAMES, and then use the Promote button to move the selection to the top of the list.
Choose Save Network Configuration from the File menu.
The sqlnet.ora
file updates with the NAMES.DIRECTORY_PATH parameter, listing tnsnames
first:
NAMES.DIRECTORY_PATH=(tnsnames, EZCONNECT)
Task 3 Copy the Configuration to the Other Clients
After one client is configured, it is best to simply copy the tnsnames.ora
and sqlnet.ora
configuration files to the same location on the other clients. This ensures that the files are consistent. Alternatively, you can use Oracle Net Assistant on every client.
Task 4 Configure the Listener
Ensure that the listener located on the server is configured to listen on the same protocol address configured for the network service name. By default, the listener is configured for the TCP/IP protocol on port 1521.
See Also:
Configuring and Administering Oracle Net Listener (page 9-1) for listener
configuration details
Task 5 Connect to the Database
Clients can connect to the database using the following syntax:
8-14 Oracle Database Net Services Administrator's Guide
Configuring the Directory Naming Method
CONNECT
username
@
net_service_name
8.3 Configuring the Directory Naming Method
With the directory naming method, connect identifiers are mapped to connect descriptors contained in an LDAP-compliant directory server, such as Oracle Internet
Directory and Microsoft Active Directory. A directory provides central administration of database services and network service names, making it easier to add or relocate services.
A database service entry is created during installation. Oracle Enterprise Manager
Cloud Control and Oracle Net Manager are used to create and modify network service names and
entries, and to modify the database service entry.
Clients can use these entries to connect to the database.
To configure the directory naming method, perform the following tasks:
•
Task 1, Verify Directory Compatibility (page 8-15)
•
Task 2, Create Net Service Names in the Directory (page 8-15)
•
Task 3, Modify Connectivity Information for Database Service Entries
(page 8-17)
•
Task 4, Create Net Services Aliases
(page 8-18)
•
Task 5, Configure LDAP as the First Naming Method for Client Lookups
(page 8-20)
•
Task 6, Configure the Listener (page 8-21)
•
Task 7, Connect to the Database
(page 8-21)
Task 1 Verify Directory Compatibility
On the computer from which you plan to create network service names, do the following verification steps:
1.
Ensure the computer has the latest release of Oracle Net Services software. The release information is located in the About Net Manager option on the help menu.
2.
Run Oracle Internet Directory Configuration Assistant to verify directory server,
Oracle Context, and Oracle schema releases.
See Also:
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for additional information about configuring directory server usage
Task 2 Create Net Service Names in the Directory
You can configure clients to use a network service name rather than the database service entry. The following procedure describes how to create network service names:
Configuring Naming Methods 8-15
Configuring the Directory Naming Method
Note:
• Only users that are members of either the
OracleNetAdmins
or
OracleContextAdmins
group can create network service name entries in a directory. To add or remove users from the
OracleNetAdmins group, see "
Who Can Add or Modify Entries in the Directory Server
(page 3-10)".
• You can export existing network service names from a tnsnames.ora
file. See "
Exporting Local Naming Entries to a Directory Naming Server
(page 8-23)".
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
6.
7.
Select Directory Naming from the Administer list, and then select the Oracle home that contains the location of the directory server.
Click Go.
The Directory Naming page appears.
Click the Net Service Names tab.
In the Results section, click Create.
The Create Net Service Name page with the General tab appears.
Enter a name in the Net Service Name field.
In the Database Information section, configure service support, as follows:
a.
Enter a destination service name.
If the destination service name is for an Oracle9i database or later, then select
Use Service Name
, and enter a service name in the Service Name field.
See Also:
"
About Connect Descriptors (page 2-5)" for additional information about the
service name string to use
b.
Select a database connection type. Oracle recommends that you use the
Database Default for the connection type. If a shared server is configured in the initialization parameter file, then the following options are available:
• Select Dedicated Server to force the listener to spawn a dedicated server, and bypass shared server configuration.
• Select Shared Server to guarantee the connection always uses shared server.
8-16 Oracle Database Net Services Administrator's Guide
Configuring the Directory Naming Method
See Also:
Configuring a Shared Server Architecture (page 11-1) for additional
information about shared server configuration
8.
In the Addresses section, configure protocol support, as follows:
a.
Click Add.
The Add Address page appears.
b.
c.
From the Protocol list, select the protocol that the listener is configured to listen. This protocol must also be installed on the client.
Enter the appropriate parameter information for the selected protocol in the fields provided.
See Also:
Oracle Database Net Services Reference
for additional information about protocol parameter settings
d.
(Optional) In the Advanced Parameters section, specify the I/O buffer space limit for send and receive operations of sessions in the Total Send Buffer Size and Total Receive Buffer Size fields.
See Also:
"
Configuring I/O Buffer Space (page 14-4)" for additional information
9.
e.
Click OK.
The protocol address is added to the Addresses section.
Click OK to add the network service name.
The network service name is added to the Results section of the Net Service
Names tab.
See Also:
•
" Creating a List of Listener Protocol Addresses (page 13-1)" to configure
multiple protocol addresses
•
" About the Advanced Connect Data Parameters (page 13-6)" to
configure additional CONNECT_DATA options
Task 3 Modify Connectivity Information for Database Service Entries
When database registration with the directory naming completes, a database service entry is created in the directory. By default, this entry contains network route information with the location of the listener through a protocol address. You can recreate this information or modify the existing network route information.
Configuring Naming Methods 8-17
Configuring the Directory Naming Method
Note:
Only users that are members of the
OracleNetAdmins
or
OracleContextAdmins
group can modify network information for a database service in a directory. To add or remove users from these groups,
see " Who Can Add or Modify Entries in the Directory Server
(page 3-10)".
The following procedure describes how to create or modify network route information for a database service:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
6.
Select Directory Naming from the Administer list, and then select the Oracle home that contains the location of the directory server.
Click Go. You may be prompted to log in to the database server and the directory server.
The Directory Naming page appears.
Click the Database Services tab.
In the Simple Search section, select Oracle Context and search criteria to see the network service names for Oracle Context.
The database service names display in the Results section.
In the Results section, select a database service, and then click Edit.
Task 4 Create Net Services Aliases
Net service aliases in a directory server enable clients to refer to a database service or a network service name by an alternative name. For example, a network service alias of salesalias
can be created for a network service name of sales
. When salesalias
is used to connect to a database, as in
CONNECT scott@salesalias
, it resolves to and use the connect descriptor information for sales
.
There are two main uses of network service aliases:
• Use a network service alias as a way for clients to refer to a database service or network service name by another name.
• Use a network service alias in one Oracle Context for a database service or network service name in a different Oracle Context. This enables a database service or network service name to be defined once in the directory server, and referred to by clients that use other Oracle Contexts.
See Also:
"
Understanding Net Service Alias Entries
(page 3-9)" for an overview of network service aliases
8-18 Oracle Database Net Services Administrator's Guide
Configuring the Directory Naming Method
Note:
• Only users that are members of either the
OracleNetAdmins
or
OracleContextAdmins
group can create or modify network service alias entries in a directory. To add or remove users from the
OracleNetAdmins
group, see "
Who Can Add or Modify Entries in the
(page 3-10)".
• To create or access network service aliases, ensure that the Oracle home is at least release 9.2.0.4.
• Net service aliases are not supported by Microsoft Active Directory.
• Ensure the NLS_LANG environment variable is set for the clients when using network service aliases.
To create a network service alias, use one of the following methods:
•
Network Service Alias Configuration using Oracle Enterprise Manager Cloud
•
Network Service Alias Configuration using Oracle Net Manager (page 8-20)
Each method provides similar functionality.
Network Service Alias Configuration using Oracle Enterprise Manager Cloud
Control
The following procedure describes how to configure a network service alias using
Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
6.
7.
Select Directory Naming from the Administer list, and then select the Oracle home that contains the location of the directory server.
Click Go.
The Directory Naming page appears.
Click the Net Service Aliases tab.
In the Results section, click Create.
The Create Net Service Alias page appears.
Enter a name for the alias in the Net Service Alias Name field.
In the Referenced Service Detail section, enter the following information in the fields:
Configuring Naming Methods 8-19
Configuring the Directory Naming Method
1.
• Oracle Context: Select the Oracle Context of the database service or network service name from the list or enter one in the field.
• Referenced Service Name: Select the DN of the database service or network service name.
8.
Click OK to add the network service alias.
The network service alias is added to the Directory Naming page.
Network Service Alias Configuration using Oracle Net Manager
The following procedure describes how to configure a network service alias using
Oracle Net Manager:
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
8.
In the navigator pane, select Service Naming from Directory.
Select Aliases.
Select Create from the Edit menu.
Enter the network service alias in the Net Service Alias field.
Select Oracle Context and name.
Click Create.
Select Save Network Configuration from the File menu.
Task 5 Configure LDAP as the First Naming Method for Client Lookups
Configure directory naming as the first method to be used in the
NAMES.DIRECTORY_PATH parameter in the sqlnet.ora
file. This parameter specifies the order of naming methods Oracle Net uses to resolve connect identifiers to connect descriptors. To configure LDAP as the first naming method you can use one of the following methods:
•
LDAP Configuration using Oracle Enterprise Manager Cloud Control
(page 8-20)
•
LDAP Configuration using Oracle Net Manager
(page 8-21)
LDAP Configuration using Oracle Enterprise Manager Cloud Control
The following procedure describes how to specify directory naming as the first naming method using Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
8-20 Oracle Database Net Services Administrator's Guide
Configuring the Directory Naming Method
2.
3.
4.
5.
6.
Select Network Profile from the Administer list.
Click Go.
Select Naming Methods.
Select LDAP from the Available Methods list.
Click Move to move the selection to the Selected Methods list.
7.
1.
Use the Promote button to move LDAP to the top of the list.
8.
Click OK.
LDAP Configuration using Oracle Net Manager
The following procedure describes how to specify directory naming as the first naming method using Oracle Net Manager:
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Naming.
Click the Methods tab.
From the Available Methods list, select LDAP, and then click the right-arrow button.
From the Selected Methods list, select LDAP, and then use the Promote button to move the selection to the top of the list.
Select Save Network Configuration from the File menu.
The sqlnet.ora
file updates with the NAMES.DIRECTORY_PATH parameter, listing ldap
first, such as the following:
NAMES.DIRECTORY_PATH=(ldap, tnsnames, hostname)
Task 6 Configure the Listener
Ensure that the listener located on the server is configured to listen on the same protocol address configured for the network service name. By default, the listener is configured to listen on the TCP/IP protocol, port 1521.
See Also:
Configuring and Administering Oracle Net Listener (page 9-1) for listener
configuration details
Configuring Naming Methods 8-21
Creating Multiple Default Contexts in a Directory Naming Server
Task 7 Connect to the Database
Clients that are configured with a default directory entry that matches the directory location of the database service or network service name can connect to the database using the following syntax:
CONNECT
username
@
connect_identifier
Clients that are configured with a default directory entry that does not match the entry's directory location must use the entry's distinguished name or its fullyqualified name.
See Also:
•
" Connect Identifier and Connect Descriptor Syntax Characteristics
(page 2-16)" for connect identifier syntax rules
•
" Understanding the Directory Information Tree
(page 3-4)" for fullyqualified name usage
8.4 Creating Multiple Default Contexts in a Directory Naming Server
If you want clients to use discovery in directories which have more than one Oracle
Context, then you can define the orclCommonContextMap
attribute in the base admin
context. This attribute overrides the orclDefaultSubscriber
attribute.
During name lookup the discovery operation returns both values, and the client decides based on these which Oracle Context to use.
If the orclCommonContextMap
attribute is not defined, then the orclDefaultSubscriber
is used as the default. If orclCommonContextMap
is defined, then the client finds the default Oracle Context which is associated with its
DNS domain in the orclCommonContextMap
. To enable multiple default contexts, define the orclCommonContextMap
with a list of associations between a domain and a DN to be used as the default oracleContext
. A sample LDIF file entry is shown here:
$ ldapmodify -v -h sales-server -p 1389 -D cn=orcladmin -q
dn: cn=Common,cn=Products,cn=OracleContext
replace: orclCommonContextMap
orclCommonContextMap:
(contextMap=
(domain_map=(domain=us.example.com)(DN="dc=example,dc=com"))
(domain_map=(domain=uk.example.com)(DN="dc=sales,dc=com"))
)
The contextMap
entry must be entered without line breaks.
See Also:
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for additional information about how to configure the directory for context mapping
8-22 Oracle Database Net Services Administrator's Guide
Exporting Local Naming Entries to a Directory Naming Server
8.5 Exporting Local Naming Entries to a Directory Naming Server
If a tnsnames.ora
file already exists, then its network service names can be exported to a directory server. The export procedure is performed for one domain at a time.
This section explains how to export data stored in a tnsnames.ora
file to a directory server. It includes the following tasks:
•
Task 1, Create Structure in the Directory Server
(page 8-23)
•
Task 2, Create Oracle Contexts (page 8-23)
•
Task 3, Configure Directory Server Usage
(page 8-24)
•
Task 4, Export Objects to a Directory Server (page 8-24)
Note:
These tasks assume the directory server has been installed and is running.
Task 1 Create Structure in the Directory Server
In the directory server, create the
directory information tree (DIT)
with the structure in which you want to import network service names. Create the structure leading to the top of the
For example, if the tnsnames.ora
file supports a domain structure example.com
and you want to replicate this domain in the directory, then create domain component entries of dc=com
and dc=example
in the directory, as shown in
Figure 8-1 example.com in Directory Server
dc=com dc=example
You can replicate the domain structure you currently use with tnsnames.ora
, or you can develop an entirely different structure. Introducing an entirely different structure can change the way clients enter the network service name in the connect string. Oracle recommends considering relative and fully-qualified naming issues before changing the structure.
See Also:
• Directory server vendor documentation for directory entry configuration instructions
•
" Client Connections Using Directory Naming (page 3-11)"
Task 2 Create Oracle Contexts
Create an Oracle Context under each DIT location that you created in Task 1 using
Oracle Internet Directory Configuration Assistant. Oracle Context has a
Configuring Naming Methods 8-23
Exporting Local Naming Entries to a Directory Naming Server
cn=OracleContext
. Oracle Context stores network
object entries, as well as other entries for other Oracle components. In Figure 8-2
(page 8-24), cn=OracleContext
is created under dc=example,dc=com
.
Figure 8-2 Oracle Context
dc=com dc=example cn=OracleContext
See Also:
•
Managing Network Address Information (page 3-1) for additional
information about Oracle Context
•
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for instructions on creating an Oracle Context
Task 3 Configure Directory Server Usage
If not done as a part of creating Oracle Contexts, then configure the Oracle home for directory server use. The Oracle home you configure should be the one that performs the export.
See Also:
Oracle Fusion Middleware Administrator's Guide for Oracle Internet Directory
for additional information about configuring directory server usage
Task 4 Export Objects to a Directory Server
To export network service names contained in a tnsnames.ora
file to a directory, use either Oracle Enterprise Manager Cloud Controlr or Oracle Net Manager.
•
Export Objects using Oracle Enterprise Manager Cloud Control
The following procedure describes how to export objects using Oracle Enterprise
Manager Cloud Control
1.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
Select Directory Naming from the Administer list, and then select the Oracle home that contains the location of the directory server.
Click Go.
The Directory Naming page appears.
8-24 Oracle Database Net Services Administrator's Guide
Exporting Local Naming Entries to a Directory Naming Server
4.
5.
6.
Click the Net Service Names tab.
In the Related Links section, click Import Net Service Names To Directory
Server
.
The Import Net Service Names To Directory Server page appears.
From the Oracle Context list in the Oracle Internet Directory Server
Destination section, select Oracle Context to which you want to export the selected network service names.
7.
8.
In the Net Service Names to Import section, select the network service names.
Click Add to add the network service names to the directory.
The network service name is added to the Directory Naming page.
•
Export Objects using Oracle Net Manager
The following procedure describes how to export objects using Oracle Net
Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
If the tnsnames.ora
file you want to export is not loaded in Oracle Net
Manager, then select Open Network Configuration from the File menu to select the tnsnames.ora
file to export to the directory.
Select Directory from the Command menu, and then select Export Net
Service Names
.
The Directory Server Migration wizard starts.
Click Next.
If network service names with multiple domain were detected in the tnsnames.ora
file, then the Select Domain page appears. Continue to Step
5.
If the network service names are not domain qualified, then the Select Net
Service Names page appears. Skip to Step 6 (page 8-25).
Select the network domain whose network service names you want to export, and then click Next.
The Select Net Service Names page appears.
Select the network service names from the list to export, and then click Next.
The Select Destination Context page appears.
In the Select Destination Context page, do the following:
Configuring Naming Methods 8-25
Exporting Directory Naming Entries to a tnsnames.ora File
8.
a.
b.
From the Directory Naming Context list, select the directory entry that contains the Oracle Context. The directory naming context is part of a directory subtree that contains one or more Oracle Contexts.
From the Oracle Context list, select the Oracle Context to which you want to export the selected network service names.
c.
Click Next.
The Directory Server Update page appears with the status of the export operation.
Click Finish to close the Directory Server Migration wizard.
8.6 Exporting Directory Naming Entries to a tnsnames.ora File
After you create the directory naming entries, consider exporting the entries to a local tnsnames.ora
file, and distributing that file to clients. Clients can use the locally saved file when a directory server is temporarily unavailable.
The following procedure describes how to export directory naming entries to a local tnsnames.ora
file:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
2.
3.
4.
5.
6.
Select Directory Naming from the Administer list, and then select the Oracle home that contains the location of the directory server.
Click Go.
The Directory Naming page appears.
Click the Net Service Names tab.
In the Simple Search section, select Oracle Context and search criteria to see the network service names for a particular Oracle Context.
The network service names display in the Results section.
In the Results section, click Save to tnsnames.ora.
The Processing: Create tnsnames.ora File page appears, informing you of the creation process.
8.7 Configuring External Naming Methods
External naming refers to the method of resolving a network service name, stored in a third-party naming service, to a network address, such as network information services (NIS). Organizations and corporations using NIS as part of their systems infrastructure have the option to store network service names and addresses in NIS, using NIS external naming.
For example, when a user gives a command with a network service name ( payroll
) such as the following:
8-26 Oracle Database Net Services Administrator's Guide
Configuring External Naming Methods
SQLPLUS scott@payroll
NIS external naming on the node running the client program or database server acting as a client program contacts an NIS server located on the network, and passes the network service name to the NIS server. The NIS server resolves the network service name into an Oracle Net address and returns this address to the client program or server. The client program then uses this address to connect to Oracle Database.
An NIS server runs a program called ypserv
, which handles name requests. The ypserv
program stores different types of data in special files called
example, passwords are stored in a map called passwd.byname
. Oracle Database service names are stored in a map called tnsnames
.
When a user uses a connect string, NIS external naming uses an RPC call to contact the ypserv
program, and passes the Oracle network service name and the name of the map. The ypserv
program looks in the tnsnames
map for the name, such as payroll
, and its address for the network service name. The address is returned to the client, and the client program uses the address to contact the database server.
Note:
The NIS external naming method is not available on all platforms. Use the adapters
command to check availability of NIS external naming on your system. If available, then it is listed under Oracle Net naming methods, as follows:
$ adapters
Installed Oracle Net naming methods are:
Local Naming (tnsnames.ora)
Oracle Directory Naming
Oracle Host Naming
NIS Naming
See Oracle platform-specific documentation for additional information.
This section contains the following tasks:
•
Task 1, Configure NIS Servers to Support NIS External Naming (page 8-27)
•
(page 8-28)
Task 1 Configure NIS Servers to Support NIS External Naming
Before configuring servers to support NIS external naming, ensure that NIS is configured and running on the NIS servers that need to resolve Oracle Database network service names. Consult your NIS documentation for specifics. To complete this task, add the tnsnames
map to the existing NIS maps, and then verify that the tnsnames
map has been installed properly.
1.
Create a tnsnames.ora
file, as specified in " Configuring the Local Naming
(page 8-7)".
Configuring Naming Methods 8-27
Configuring External Naming Methods
Note:
Keep a copy of the tnsnames.ora
file, preferably in the
ORACLE_HOME/ network/admin
directory. You may need to use this file again later to load network service names into the NIS map.
2.
Convert the contents of the tnsnames.ora
file to a tnsnames
map using the tns2nis
program using a command similar to the following: tns2nis tnsnames.ora
The tns2nis
program reads the tnsnames.ora
file from the current directory.
If the tnsnames.ora
file is not located in the current directory, then use a full path name to specify its location, such as
/etc/tnsnames.ora
or
ORACLE_HOME/network/admin/tnsnames.ora
.
The tnsnames
map is then written into the current working directory.
Note:
The tns2nis
program is supplied with NIS external naming.
3.
4.
Copy the tnsnames
map to the NIS server.
Install the tnsnames
map using makedbm
, which is an NIS program.
Note:
This step must be performed by the person in charge of NIS administration.
The makedbm
program converts the tnsnames
map into two files that the NIS server can read. The location of these files is operating system specific.
For example, to generate and install a tnsnames
map on Linux, as the root user, enter the following at the command line:
# makedbm tnsnames /var/yp/'domainname'/tnsnames
See Also:
Oracle operating system-specific documentation for details
5.
Verify tnsnames
has been installed properly using the following command: ypmatch
net_service_name
tnsnames
For example, you might enter the following command: ypmatch example.com tnsnames
This returns the length of the address in characters, followed by the address such as the following:
99 (description=(address=(protocol=tcp) (host=sales)(port=1999)))
(connect_data=(service_name=dirprod)))
8-28 Oracle Database Net Services Administrator's Guide
Configuring External Naming Methods
Task 2 Configure the Clients
To configure clients, configure NIS as the first method specified in the
NAMES.DIRECTORY_PATH parameter in the sqlnet.ora
file. This parameter specifies the order of naming methods Oracle Net can use to resolve connect identifiers to connect descriptors.
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Naming.
Click the Methods tab.
From the Available Methods list, select NIS, and then click the right-arrow button.
In the Selected Methods list, select NIS, and then use the Promote button to move the selection to the top of the list.
Select Save Network Configuration from the File menu.
The sqlnet.ora
file updates with the NAMES.DIRECTORY_PATH parameter, listing nis
first:
NAMES.DIRECTORY_PATH=(nis, hostname, tnsnames)
Configuring Naming Methods 8-29
Configuring External Naming Methods
8-30 Net Services Administrator's Guide
9
Configuring and Administering Oracle Net
Listener
Oracle Net Listener is a separate process that runs on the database server. It receives incoming client connection requests and manages the traffic of these requests to the database server. Find out how to configure the listener to accept client connections.
•
Overview of Oracle Net Listener (page 9-1)
•
Configuring Dynamic Service Registration (page 9-2)
•
Configuring Oracle Net Listener During Installation
(page 9-10)
•
Customizing Oracle Net Listener Configuration
(page 9-10)
•
(page 9-13)
•
Understanding Listener Redirects (page 9-20)
Note:
In Oracle Database 12c release 2 (12.2), the listener password feature is no longer supported. This does not cause a loss of security because authentication is enforced through local operating system authentication. Refer to Oracle
Database Net Services Reference
for additional information.
See Also:
•
Identifying and Accessing the Database
(page 2-1) for a description of how the listener is used during an initial connection request
•
Understanding the Communication Layers (page 4-1) for an architectural
overview of the listener
9.1 Overview of Oracle Net Listener
Note:
The release of the listener must be the same as or later than the latest release of all Oracle databases being serviced through the listener.
Configuring and Administering Oracle Net Listener 9-1
Configuring Dynamic Service Registration
A listener is configured with one or more listening protocol addresses, information about supported services, and parameters that control its runtime behavior. The listener configuration is stored in a configuration file named listener.ora
.
Because the configuration parameters have default values, it is possible to start and use a listener with no configuration. This default listener has a name of
LISTENER
, supports no services on startup, and listens on the following TCP/IP protocol address:
(ADDRESS=(PROTOCOL=tcp)(HOST=
host_name
)(PORT=1521))
The listener forwards client requests to supported services. These services are dynamically registered with the listener. This dynamic registration feature is called
. The registration is performed by the Listener Registration (LREG) process. Dynamic service registration does not require any manual configuration in the listener.ora
file.
Service registration offers the following benefits:
• Connect-time failover
Because the listener always monitors the state of the instances, service registration facilitates automatic failover of a client connect request to a different instance if one instance is down.
• Connection load balancing
Service registration enables the listener to forward client connect requests to the least-loaded instance and
. Service registration
• High-availability for Oracle Real Application Clusters and Oracle Data Guard
See Also:
•
" Understanding Oracle Net Architecture
(page 5-1)"
•
" Configuring Dynamic Service Registration
(page 9-2)"
•
" About the Address List Parameters (page 13-4)"
•
" Understanding Connection Load Balancing
(page 13-8)"
9.2 Configuring Dynamic Service Registration
Service registration allows processes, such as an Oracle database, to identify their available services to the listener, which then acts as a port mapper for those services.
The listener uses the dynamic service information about the database and instance received through service registration.
Dynamic service registration is configured in the database initialization file. It does not require any configuration in the listener.ora
file. However, listener configuration must be set to listen on the ports named in the database initialization file, and must not have parameters set that prevent automatic registration, such as COST parameters.
This section contains the following configuration topics related to service registration:
•
Setting Initialization Parameters for Service Registration
(page 9-3)
9-2 Oracle Database Net Services Administrator's Guide
Configuring Dynamic Service Registration
•
Registering Information with a Local Listener (page 9-3)
•
Registering Information with a Remote Listener (page 9-5)
•
Registering Information with All Listeners in a Network (page 9-7)
•
(page 9-9)
9.2.1 Setting Initialization Parameters for Service Registration
To ensure service registration works properly, the initialization parameter file should contain the following parameters:
• SERVICE_NAMES for the database service name
• INSTANCE_NAME for the instance name
• LOCAL_LISTENER for the local listener
• REMOTE_LISTENER for the remote listener, if any
For example:
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales
The value for the SERVICE_NAMES parameter defaults to the
, a name comprising the DB_NAME and DB_DOMAIN parameters in the initialization parameter file. The value for the INSTANCE_NAME parameter defaults to the Oracle system identifier (SID).
See Also:
Oracle Database Reference
for additional information about the
SERVICE_NAMES and INSTANCE_NAME parameters
9.2.2 Registering Information with a Local Listener
By default, the LREG process registers service information with its local listener on the default local address of TCP/IP, port 1521. If the listener configuration is synchronized with the database configuration, then LREG can register service information with a nondefault local listener or a remote listener on another node.
Synchronization occurs when the protocol address of the listener is specified in the listener.ora
file and the location of the listener is specified in the initialization parameter file.
To have the LREG process register with a local listener that does not use TCP/IP, port
1521, configure the LOCAL_LISTENER parameter in the initialization parameter file to locate the local listener.
For a shared server environment, you can use the
LISTENER
attribute of the
DISPATCHERS parameter in the initialization parameter file to register the dispatchers with a nondefault local listener. Because the LOCAL_LISTENER parameter and the
LISTENER
attribute enable LREG to register dispatcher information with the listener, it is not necessary to specify both the parameter and the attribute if the listener values are the same.
Configuring and Administering Oracle Net Listener 9-3
Configuring Dynamic Service Registration
LOCAL_LISTENER is a comma-delimited list parameter. If a comma appears in the string, then the entire string must be enclosed in double quotation marks. Set the
LOCAL_LISTENER parameter as follows:
ALTER SYSTEM SET LOCAL LISTENER=["]listener_address["][,...];
For example, if the listener address
"ab,cd"
is entered, then it resolves to one listener address. If the address is entered as ab,cd
, then it resolves to two listener addresses, ab
and cd
.
For shared server connections, set the
LISTENER
attribute as follows:
ALTER SYSTEM SET DISPATCHERS="(PROTOCOL=tcp)(LISTENER=listener_address)";
In the preceding command, listener_address is resolved to the listener protocol addresses through a naming method, such as a tnsnames.ora
file on the database server.
Note:
• To dynamically update the LOCAL_LISTENER parameter, use the SQL statement
ALTER SYSTEM
as follows:
ALTER SYSTEM SET LOCAL_LISTENER=["]listener_address["][,...]
If you set the parameter to null using the following statement, then the default local address of TCP/IP, port 1521 is assumed:
ALTER SYSTEM SET LOCAL_LISTENER=''
• The
LISTENER
attribute overrides the LOCAL_LISTENER parameter. As a result, the SQL statement
ALTER SYSTEM SET LOCAL_LISTENER does not affect the setting of this attribute.
In
(page 9-4), a database resides on host sales1-server
. The listener on this host is named listener_sales1
and is configured to listen on port 1421 instead of port 1521.
Example 9-1 Registering a Local Listener in a Dedicated Server Environment
1.
2.
On the host where the local listener resides, configure the listener.ora
file with the protocol address of the listener using Oracle Net Manager.
On the database, set the LOCAL_LISTENER parameter in the database initialization parameter file to the alias of the local listener. For example:
ALTER SYSTEM SET LOCAL_LISTENER=listener_sales1;
3.
If the database is configured for shared server connections, then you could set the
LISTENER
attribute as follows:
ALTER SYSTEM SET DISPATCHERS="(PROTOCOL=tcp)(LISTENER=listener_sales1)";
Resolve the listener name alias for the
LOCAL_LISTENER
setting through a tnsnames.ora
file on the database host using a text editor, as follows: listener_sales1=
(DESCRIPTION =
(ADDRESS = (PROTOCOL=tcp)(HOST=sales-server)(PORT=1421)))
9-4 Oracle Database Net Services Administrator's Guide
Configuring Dynamic Service Registration
Note:
• If you are registering a local listener and use Oracle Connection Manager, then do not include
(DESCRIPTION =
or its closing parenthesis.
• A network service name entry can be created for the protocol address without the CONNECT_DATA section of the connect descriptor.
See Also:
• See Oracle Database SQL Reference for additional information about the
ALTER SYSTEM
statement.
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
" Configuring a Naming Method (page 9-9)"
9.2.3 Registering Information with a Remote Listener
A remote listener is a listener residing on one computer that redirects connections to a database instance on another computer. Remote listeners are typically used in an
Oracle Real Application Clusters (Oracle RAC) environment. You can configure registration to remote listeners, such as with Oracle RAC, for dedicated or shared server environments.
In a dedicated server environment, you must enable the LREG background process to register with a remote listener. You do this by configuring the REMOTE_LISTENER parameter, which is a comma-delimited list parameter, in the initialization parameter file. The syntax of REMOTE_LISTENER is as follows:
ALTER SYSTEM SET REMOTE_LISTENER=["]listener_address["][,...];
In the preceding command, listener_address is resolved to the listener protocol addresses through a naming method such as a tnsnames.ora
file on the database host. If a comma appears in the listener address, then the entire string must be enclosed in quotation marks.
In a shared server environment, you can use the same registration technique as for a dedicated server environment. Alternatively, you can set the
LISTENER
attribute of the DISPATCHERS parameter in the initialization parameter file to register the dispatchers with any listener. The syntax of the
LISTENER
attribute is as follows:
ALTER SYSTEM SET DISPATCHERS="(PROTOCOL=tcp)(LISTENER=listener_address)";
Note:
The
LISTENER
attribute overrides the REMOTE_LISTENER initialization parameter. Because the REMOTE_LISTENER initialization parameter and the
LISTENER
attribute enable LREG to register dispatcher information with the listener, you do not need specify both the parameter and the attribute if the listener values are the same.
Configuring and Administering Oracle Net Listener 9-5
Configuring Dynamic Service Registration
For example, assume that a remote listener named listener-sales2
listens on port
1521 on host sales2-server
, and a database resides on host sales1-server
. You want the listener on sales2-server
to redirect connection requests to this database.
Figure 9-1 (page 9-6) illustrates this scenario.
Figure 9-1 Remote Listener
sales1-server sales2-server listener-sales2
Listener
Client
See Also:
Oracle Database SQL Reference
for additional information about the
ALTER
SYSTEM SET
statement
Example 9-2 (page 9-6) shows how to register a remote listener in a dedicated server
environment. In the example, the remote listener is sales2-server
.
Example 9-2 Registering a Remote Listener in a Dedicated Server Environment
1.
2.
On the host where the remote listener resides, use Oracle Net Manager to configure the listener.ora
file with the protocol addresses of the remote listener.
On the database to which you want requests to be redirected, set the
REMOTE_LISTENER parameter in the database initialization parameter file to the alias of the remote listener, for example:
ALTER SYSTEM SET REMOTE_LISTENER=listener_sales2;
For shared server connections, set the DISPATCHER parameter in the initialization file for the database on host sales1-server
as follows:
ALTER SYSTEM SET DISPATCHERS="(PROTOCOL=tcp)(LISTENER=listeners_sales2)";
Note:
To statically update the REMOTE_LISTENER initialization parameter, use a text editor to de-register the information with the remote listener which it had previously registered information.
3.
Resolve the listener name alias for the remote listener through a tnsnames.ora
file on the database host. For example:
9-6 Oracle Database Net Services Administrator's Guide
Configuring Dynamic Service Registration listener_sales2=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
See Also:
•
" Configuring a Naming Method (page 9-9)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
Oracle Database Reference
to learn about the REMOTE_LISTENER initialization parameter
•
Oracle Real Application Clusters Administration and Deployment Guide
to learn how to configure remote listeners (also called SCAN listeners) in an
Oracle RAC environment
9.2.4 Registering Information with All Listeners in a Network
A network may contain multiple local and remote listeners. By default, all listeners are cross-registered with each other. By specifying a set of listeners in the
LISTENER_NETWORKS initialization parameter, you can designate a subset of local listeners with a subset of remote listeners. Listeners specified by the
LISTENER_NETWORKS parameter should not be specified by the
LOCAL_LISTENER and REMOTE_LISTENER parameters.
The syntax of LISTENER_NETWORKS parameter is as follows:
LISTENER_NETWORKS = '((NAME=network_name)
(LOCAL_LISTENER=["]listener_address[,...]["])
[(REMOTE_LISTENER=["]listener_address[,...]["])])'
In the preceding syntax, listener_address is resolved according to the rules of
LOCAL_LISTENER and REMOTE_LISTENER.
Example 9-3 Using Two Networks on a Subnet
Assume there are two distinct networks, network1
and network2
. On network1
, there is a local listener named local1
, and a remote listener named remote1
. On network2
, there is a local listener named local2
, and a remote listener named remote2
. The following syntax sets up registration so that the listeners only redirect connections to listeners on the same network.
LISTENER_NETWORKS =
'((NAME=network1) (LOCAL_LISTENER=local1) (REMOTE_LISTENER=remote1))',
'((NAME=network2) (LOCAL_LISTENER=local2) (REMOTE_LISTENER=remote2))'
In the preceding example, local1
is registered only with remote1
, and remote1 only redirects connections to local1
. The listener local2
is registered only with remote2
, and remote2
only redirects connections to local2
.
Example 9-4 Configuring Multiple Listeners
Assume that multiple listeners are listening on a network named sales-network
.
The following conditions are true:
• A database configured for dedicated server connections resides on host sales1server
. It is the only database in the network.
Configuring and Administering Oracle Net Listener 9-7
Configuring Dynamic Service Registration
• A local listener resides on sales1-server
and listens on nondefault port 1421.
• A remote listener named resides on host sales2-server
and listens on port
1521.
• Another remote listener resides on host sales3-server
and listens on port
1521.
The following procedure describes how to register information with all listeners in a dedicated server environment:
1.
On the hosts where the remote listeners reside (in this example, sales2-server and sales3-server
), configure the listener.ora
file with the protocol addresses of the remote listener.
2.
On the database to which you want requests to be redirected, set the
REMOTE_LISTENER parameter in the database initialization parameter file to the alias of the remote listeners, and the LOCAL_LISTENER parameter to the alias of the local listener.
Set the parameters in the initialization file for the database on host sales1server
as follows:
3.
REMOTE_LISTENER="listener_sales2,listener_sales3"
LOCAL_LISTENER=listener_sales1
Resolve the listener name alias for the LOCAL_LISTENER and
REMOTE_LISTENER setting through a tnsnames.ora
file on the database host.
In the tnsnames.ora
on sales1-server
, resolve the local listener alias and remote listener aliases
listener_sales1
, listener_sales2
, and listener_sales3
as follows: listener_sales1=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=sales1-server)(PORT=1421))) listener_sales2=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=sales2-server)(PORT=1521))) listener_sales3=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=sales3-server)(PORT=1521))) listener_sales_local=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=salesl-server)(PORT=1421))) listener_sales_remote=
(DESCRIPTION_LIST=
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales3-server)(PORT=1521))))
9-8 Oracle Database Net Services Administrator's Guide
Configuring Dynamic Service Registration
See Also:
•
" Configuring a Naming Method (page 9-9)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
•
Oracle Database Reference
for additional information about the
REMOTE_LISTENER initialization parameter
9.2.5 Configuring a Naming Method
The listener name alias specified for the LOCAL_LISTENER or REMOTE_LISTENER initialization parameters, or
LISTENER
attribute can be resolved using a tnsnames.ora
file. For example, a listener can be defined in the init.ora
file as the following:
LOCAL_LISTENER = (ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1421))
To use an alias for the listener, it can be defined in the init.ora
and the tnsnames.ora
files as follows:
• In the init.ora
file:
LOCAL_LISTENER = listener_sales1
• In the tnsnames.ora
file: listener_sales1 = (ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1421))
The CONNECT_DATA information should not be included in the network service entry in the tnsnames.ora
file. However, Oracle Enterprise Manager Cloud Control and Oracle Net Manager cannot configure a tnsnames.ora
file without the
CONNECT_DATA information. To use listener name aliases, Oracle recommends you modify the tnsnames.ora
file using a text editor.
Note:
• Multiple addresses are supported, but connect-time failover and client load balancing features are not supported.
• If the listener alias specified in the LOCAL_LISTENER parameter is invalid or not resolved, then the LREG process does not allow the database to start. The following errors occur:
ORA-00119: invalid specification for system parameter
LOCAL_LISTENER
ORA-00132: syntax error or unresolved network name '%s'
See Also:
Enabling Advanced Features of Oracle Net Services
(page 13-1) for additional information about multiple address configuration
Configuring and Administering Oracle Net Listener 9-9
Configuring Oracle Net Listener During Installation
9.3 Configuring Oracle Net Listener During Installation
Oracle Universal Installer launches
Oracle Net Configuration Assistant
installation. Oracle Net Configuration Assistant configures the listening protocol address and service information for Oracle Database.
During an Enterprise Edition or Standard Edition installation on the database server,
Oracle Net Configuration Assistant automatically configures a listener with a name of
LISTENER
that has a TCP/IP listening protocol address for Oracle Database. During a
Custom installation, Oracle Net Configuration Assistant prompts for the listener name and protocol address.
A listening IPC protocol address for
calls is automatically configured, regardless of the installation type. Oracle Net Configuration Assistant also automatically configures service information for the external procedures in the listener.ora
file.
If you are using the IPC protocol, then you can improve performance by specifying the maximum number of concurrent IPC connection requests to match your expected connection requests.
9.4 Customizing Oracle Net Listener Configuration
If the default or installed configuration is not adequate for a particular environment, then you can use
listener.ora
configuration.
This section contains the following configuration topics:
•
Configuring Listening Protocol Addresses (page 9-10)
•
Handling Large Volumes of Concurrent Connection Requests
(page 9-12)
•
Managing Oracle Net Listener Security (page 9-12)
9.4.1 Configuring Listening Protocol Addresses
Oracle Enterprise Manager Cloud Control and Oracle Net Manager can be used to configure protocol support for the listener.
The Oracle Net Listener endpoint address configuration accepts both IPv6 addresses
and host names that resolve to IPv6 addresses, as explained in " IPv6 Interface and
Address Configurations (page 4-9)". This technique can create listening endpoints that
service IPv6 clients.
9.4.1.1 Configuring Listening Protocol Addresses Using Oracle Enterprise Manager
Cloud Control
The following procedure describes how to configure protocol addresses for the listener using Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Accessing the Net Services Administration Page
(page 7-2)"
9-10 Oracle Database Net Services Administrator's Guide
Customizing Oracle Net Listener Configuration
2.
3.
4.
Click Edit. You may be prompted to log in to the database server.
The Edit Listener page appears.
In the Addresses section, configure protocol support:
a.
b.
c.
Click Add.
The Add Address page appears.
From the Protocol list, select the protocol on which the listener is configured to listen.
For TCP/IP, if the computer has more than one IP address and you want the listener to listen on all available IP addresses, then select TCP/IP or TCP/IP
with SSL
and enter the host name of the computer in the Host field.
In Port, enter the port number.
When configuring the listener to listen on TCP/IP, enter the default port of
1521. Otherwise, you must configure the LOCAL_LISTENER parameter in the initialization parameter file and the non-default port number must be specified for use by any naming method.
d.
e.
f.
In Host, enter the host address.
(Optional) In the Advanced Parameters section, specify the I/O buffer space limit for send and receive operations of sessions in the Total Send Buffer Size and Total Receive Buffer Size fields.
Click OK.
The protocol address is added to the Addresses section.
Repeat Step 3 (page 9-11) for additional protocols.
See Also:
•
Oracle Database Net Services Reference
for additional information about protocol addresses and TCP/IP privileged ports
•
" Configuring I/O Buffer Space (page 14-4)" for additional information
9.4.1.2 Configuring Listening Protocol Addresses Using Oracle Net Manager
The following procedure describes how to configure protocol addresses for the listener using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
In the navigator pane, expand Local, and then select Listeners.
Select the listener.
Configuring and Administering Oracle Net Listener 9-11
Customizing Oracle Net Listener Configuration
4.
5.
6.
7.
8.
9.
From the list in the right pane, select Listener Locations.
Select the protocol from the Protocol list.
Enter the host name for the listener in the Host field.
Enter the port number in the Port field.
If you want to set send and receive buffer sizes, then click Show Advanced, and then enter the sizes in the appropriate fields.
Select Save Network Configuration from the File menu to save the changes.
9.4.2 Handling Large Volumes of Concurrent Connection Requests
If you expect the listener to handle large volumes of concurrent connection requests, then you can specify a listener queue size for its TCP/IP or IPC listening endpoints.
To specify the listener queue size, do the following:
• Specify the
QUEUESIZE
parameter at the end of the protocol address with its value set to the expected number of concurrent requests.
The following example sets the queue size to 20:
LISTENER=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)(QUEUESIZE=20)))
Note:
The default number of concurrent connection requests is operating systemspecific. The defaults for TCP/IP on the Linux operating system and Microsoft
Windows follow:
– Linux operating system: 128
– Microsoft Windows XP Professional SP2: 10
– Microsoft Windows Server Enterprise Edition: 200
9.4.3 Managing Oracle Net Listener Security
By default, Oracle Net Listener permits only local administration for security reasons.
As a policy, the listener can be administered only by the user who started it. This is enforced through local operating system authentication. For example, if user1
starts the listener, then only user1
can administer it. Any other user trying to administer the listener gets an error. The super user is the only exception.
Oracle recommends that you perform listener administration in the default mode
(secure by means of local operating system authentication), and access the system remotely using a remote login. Oracle Enterprise Manager Cloud Control can also be used for remote administration.
Connections coming to listener on an IP (TCP, TCPS, and SDP) based endpoint with firewall functionality enabled, go through service ACL validation. The listener after receiving the service name validates the connection IP with ACL list.
A new attribute FIREWALL is added in the endpoint to enable firewall functionality.
9-12 Oracle Database Net Services Administrator's Guide
Administering the Listener
(ADDRESS=(PROTOCOL=TCP)(HOST=)(PORT=1521)(FIREWALL=ON))
The
FIREWALL
parameter can be configured as follows:
•
(FIREWALL=ON)
is explicitly set in endpoint – This enables strict ACL validation
(whitelist-based approach) of all connections coming on this endpoint. If no ACLs are configured for a service, all connections are rejected for that service.
•
FIREWALL
is not set in endpoint – This implies relaxed validation. If ACL is configured for a service, validation is done for that service. In the absence of
ACLs, no validation is done and all connections for that service are accepted.
•
(FIREWALL=OFF)
is set in endpoint – No validation is done and all connections are accepted from this endpoint.
The server also enforces the ACLs.
Related Topics:
Service-Level ACLs for TCP Protocol (page xvii)
9.4.3.1 Specifying Valid Nodes and Subnets
Listener registration should be restricted to valid nodes and subnets. Valid nodes and subnets can be specified for registration, and excluded nodes can also be specified for registration. By default, every incoming connection for registration at the listener is subjected to IP-based filtering. A connection is only allowed if it originates from the local machine. If the other nodes and subnets are specified for registration, then the local machine and the ones specified are allowed. The following parameters can be set in the listener.ora
file to specify valid and restricted nodes and subnets:
• REGISTRATION_INVITED_NODES_listener_name: Specifies the nodes that can register with the listener. The list can be host names, or CIDR notation for IPv4 and IPv6 addresses. Presence of a host name in the list results in all IP addresses mapped to it being invited.
• REGISTRATION_EXCLUDED_NODES_listener_name: Specifies the nodes that cannot register with the listener. Nodes not specified on the list are allowed to register with the listener.
If both parameters are set, then REGISTRATION_EXCLUDED_NODES_listener_name is ignored.
See Also:
Oracle Database Net Services Reference
for additional information about valid node registration checking.
9.5 Administering the Listener
After the listener is configured, you can administer it with the Listener Control utility,
Oracle Enterprise Manager Cloud Control, and the Server Control utility (SRVCTL).
This section describes some of the administrative tasks for the listener. It contains the following topics:
•
Starting and Stopping a Listener (page 9-14)
Configuring and Administering Oracle Net Listener 9-13
Administering the Listener
•
Managing a Listener in an Oracle Restart Configuration (page 9-15)
•
Determining the Current Status of a Listener
(page 9-16)
•
Monitoring Services of a Listener
(page 9-18)
•
(page 9-20)
See Also:
•
Oracle Database Net Services Reference
for a complete list of the Listener
Control utility commands
• Oracle Enterprise Manager Cloud Control online help
9.5.1 Starting and Stopping a Listener
To stop or start a listener, use one of the following methods:
•
Starting or Stopping a Listener Using the Listener Control Utility (page 9-14)
•
Starting or Stopping a Listener Using Oracle Enterprise Manager Cloud Control
(page 9-15)
Note:
You can configure the listener to start automatically whenever the computer is running or is restarted. Refer to "
Managing a Listener in an Oracle Restart
Configuration (page 9-15)" for additional information.
9.5.1.1 Starting or Stopping a Listener Using the Listener Control Utility
To start the listener from the command line, enter: lsnrctl START [listener_name]
In the preceding command, listener_name is the name of the listener defined in the listener.ora
file. It is not necessary to identify the listener if you are using the default listener name
LISTENER
.
In addition to starting the listener, the Listener Control utility verifies connectivity to the listener.
To stop a listener from the command line, enter: lsnrctl STOP [listener_name]
In the preceding command, listener_name is the name of the listener defined in the listener.ora
file. It is not necessary to identify the listener if you are using the default listener name
LISTENER
.
9-14 Oracle Database Net Services Administrator's Guide
Administering the Listener
Note:
When using the Oracle Home User, the listener control utility prompts for a password on Microsoft Windows systems. This password is the operating system password for the Oracle Home User. The password prompt is displayed only if the listener service does not exist and needs to be created as part of starting the listener.
See Also:
Oracle Database Platform Guide for Microsoft Windows
for information about the
Oracle Home User
9.5.1.2 Starting or Stopping a Listener Using Oracle Enterprise Manager Cloud
Control
The following procedure describes how to start or stop a listener from Oracle
Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
6.
7.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Click Go.
The Listeners page appears.
Select the listener.
From the Actions list, select Start/Stop.
Click Go.
The Start/Stop page appears.
Depending on the current status of the selected listener, select either Stop or Start, and then click OK.
9.5.2 Managing a Listener in an Oracle Restart Configuration
The Oracle Restart feature enhances availability for the processes and applications in a single-instance database environment. The Oracle Restart agents monitor the health of added components by periodically running check operations and restarting the components when necessary.
You can add the listener as a component to the Oracle Restart configuration. The listener is then automatically started by Oracle Restart when it fails or is not running.
For example, if you restart the database instance after a planned restart of the
Configuring and Administering Oracle Net Listener 9-15
Administering the Listener computer, then Oracle Restart restarts the listener. Server Control (SRVCTL) is a command-line interface that you can use to manage listeners in an Oracle Restart configuration.
9.5.2.1 Viewing Configured Listeners Using the SRVCTL Utility
To view all configured listeners, use the following command:
% srvctl config listener
See Also:
Oracle Database Administrator's Guide
to learn how to configure Oracle Restart and for SRVCTL syntax and semantics
9.5.2.2 Adding or Removing a Listener Using the SRVCTL Utility
Adding a listener as an entry to the grid infrastructure enables the agent to monitor the listener. Similarly, removing a listener removes as an entry. Use the srvctl command at the operating system command line as follows:
• To add the listener, enter srvctl add listener
The following command adds an entry for listener_sales1
to the grid infrastructure:
% srvctl add listener -listener listener_sales1
• To remove the listener, enter srvctl remove listener
The following command removes the entry for listener_sales1
from the grid infrastructure:
% srvctl remove listener -listener listener_sales1
9.5.2.3 Starting or Stopping a Listener Using the SRVCTL Utility
The SRVCTL utility enables you to stop and start the listener. If you do not specify the
-listener
parameter, then the SRVCTL utility starts and stops the default listener.
• To start a listener, enter srvctl start listener
In the following example, the first command starts the default listener, and the second command starts listener1
and listener2
:
% srvctl start listener
% srvctl start listener -listener listener1,listener2
• To stop a listener, enter srvctl stop listener
In the following example, the first command stops the default listener, and the second command stops listener1
and listener2
:
% srvctl stop listener
% srvctl stop listener -listener listener1,listener2
9.5.3 Determining the Current Status of a Listener
To show the current status of a listener, use either the
STATUS
command of the
Listener Control utility or Oracle Enterprise Manager Cloud Control. The status output provides basic status information about a listener, a summary of listener
9-16 Oracle Database Net Services Administrator's Guide
Administering the Listener configuration settings, the listening protocol addresses, and a summary of services registered with the listener.
9.5.3.1 Showing Status Using Listener Control
To show the status the listener from the command line, enter the following command: lsnrctl STATUS [listener_name]
In the preceding command, listener_name is the name of the listener defined in the listener.ora
file. It is not necessary to identify the listener if you are using the default listener name
LISTENER
.
Example 9-5 (page 9-17) shows example output of the
STATUS
command.
Example 9-5 Listener Control Utility's STATUS Command Output
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=net)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 12.2.0.1.0
Start Date 15-MAY-2016 20:22:00
Uptime 65 days 10 hr. 5 min. 22 sec
Trace Level support
Security OFF
Listener Parameter File /oracle/admin/listener.ora
Listener Log File /oracle/network/log/listener.log
Listener Trace File /oracle/network/trace/listener.trc
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=net)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=sales-server)(PORT=2484)))
Services Summary...
Service "sales.us.example.com" has 1 instance(s).
Instance "sales", status READY, has 3 handler(s) for this service...
Service "hr.us.example.com" has 1 instance(s).
Instance "hr", status READY, has 2 handler(s) for this service...
The command completed successfully
The
STATUS
command output includes the sections described in Table 9-1
(page 9-17).
Table 9-1 Listener Control Utility STATUS Command
Output Section
STATUS of the
LISTENER
Description
Status of the listener, including the following:
• Alias of the listener
• Version of listener
• Start time and up time
• Trace level
• listener.ora
file being used
• Logging and tracing configuration settings
The protocol addresses the listener is configured to listen on.
Listening Endpoints
Summary
Services Summary A summary of the services registered with the listener and the service handlers allocated to each service.
Configuring and Administering Oracle Net Listener 9-17
Administering the Listener
Table 9-1 (Cont.) Listener Control Utility STATUS Command
Output Section
Service
Instance
Description
The registered service.
The name of the instance associated with the service.
The status field indicates if the instance can accept connections.
•
READY
means that the instance can accept connections.
•
BLOCKED
means that the instance cannot accept connections.
•
READY/SECONDARY
means that this is a secondary instance in an Oracle Real Application Clusters primary/secondary configuration, and is ready to accept connections.
•
RESTRICTED
means the instance is in restricted mode. The listener blocks all connections to this instance.
•
UNKNOWN
means that the instance is registered statically in the listener.ora
file rather than dynamically with service registration. Therefore, the status is not known.
9.5.3.2 Showing Status Using Oracle Enterprise Manager Cloud Control
The following procedure describes how to show the status of a listener using Oracle
Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
6.
7.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Click Go. You may be prompted to log in to the database server.
The Listeners page appears.
Select a listener.
From the Actions list, select Show Listener Control Status.
Click Go.
The Listener Control Status page appears.
After viewing the content, click the listener link at the top of the page.
9.5.4 Monitoring Services of a Listener
The
SERVICES
command of the Listener Control utility provides detailed information about the services and instances registered with a listener and the service handlers allocated to each instance. To show information about the services and instances from the command line, enter: lsnrctl SERVICES [listener_name]
9-18 Oracle Database Net Services Administrator's Guide
Administering the Listener
Example 9-6 (page 9-19) shows example output of the
SERVICES
command.
Example 9-6 Listener Control Utility's SERVICES Command Output
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=net)))
Services Summary...
Service "sales.us.example.com" has 1 instance(s).
Instance "sales", status READY, has 3 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
"D000" established:0 refused:0 current:0 max:10000 state:ready
DISPATCHER <machine: sales-server, pid: 1689>
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=52414))
"D001" established:0 refused:0 current:0 max:10000 state:ready
DISPATCHER <machine: sales-server, pid: 1691>
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=52415))
Service "hr.us.example.com" has 1 instance(s).
Instance "hr", status READY, has 2 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
"D000" established:0 refused:0 current:0 max:10000 state:ready
DISPATCHER <machine: sales-server, pid: 11326>
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=58361))
The command completed successfully
This output shows that two database services, sales.us.example.com
and hr.us.example.com
, are registered with the listener.
Client connection requests to sales.us.example.com
are handled by two dispatchers named
D000
and
D001
and one dedicated server. All handlers have a status of ready
, indicating that they are ready to receive connections.
Client connection requests to hr.us.example.com
are handled by one dispatcher named
D001
and one dedicated server.
The
SERVICES
command generates output with the following information as described in
(page 9-19).
Table 9-2 Listener Control Utility SERVICES Command
Output Section
Services
Instance
Description
The registered service.
The name of the instance associated with the service
The status field indicates if the instance can accept connections.
•
READY
means the instance can accept connections.
•
BLOCKED
means the instance cannot accept connections.
•
READY/SECONDARY
means the is a secondary instance in an Oracle
Real Application Clusters primary/secondary configuration and is ready to accept connections.
•
RESTRICTED
means the instance is in restricted mode. The listener blocks all connections to this instance.
•
UNKNOWN
means the instance is registered statically in the listener.ora
file rather than dynamically with service registration. Therefore, the status is non known.
Configuring and Administering Oracle Net Listener 9-19
Understanding Listener Redirects
Table 9-2 (Cont.) Listener Control Utility SERVICES Command
Output Section
Handlers
Description
The name of the service handler. Dispatchers are named
D000
through
D999
. Dedicated servers have the name of
DEDICATED
.
This section also identifies the following about the service handler:
• established
: The number of client connections this service handler has established.
• refused
: The number of client connections it has refused.
• current
: The number of client connections it is handling, that is, its current load.
• max
: The maximum number of connections for the service handler, that is, its maximum load.
• state
: The state of the handler:
-
READY
means the service handler can accept new connections.
-
BLOCKED
means the service handler cannot accept new connections.
9.5.5 Monitoring Listener Log Files
When you notice any of the following conditions, review the listener log file for error information:
• Long connection establishment times
• Connectivity problems and refusals
• Unexpected shutdown of the listener that could indicate a denial-of-service attack
See Also:
"
(page 16-29)"
9.6 Understanding Listener Redirects
Starting with Oracle Database 12c release 2 (12.2), the listener redirect feature allows a client to connect to a pluggable database (PDB) using an unchanged connect descriptor even after the PDB is migrated to a new location in the Oracle Public Cloud.
The Listener Registration (LREG) process registers a new handler with the local listener for the PDB or the service which is in the process of migration. This handler contains the new listener address of the database where the PDB or the service is
migrated. The new listener address can be that of a
listener in case of an Oracle RAC database or a local listener in case of a single-instance database. The listener then redirects the client to the new address.
If a local listener redirects to a SCAN listener in an Oracle RAC configuration, then this listener may need to further redirect the client connection request to another cluster node. Such multiple redirects are not supported by Oracle Net listeners by default. To allow the SCAN listener to forward the already redirected client connection request, add the
ALLOW_MULTIPLE_REDIRECTS_
listener_name
parameter to its listener.ora
file. Set the parameter to
TRUE.
Do not set this parameter for
9-20 Oracle Database Net Services Administrator's Guide
Understanding Listener Redirects node listeners because it may allow infinite redirection loops in certain network configurations.
Configuring and Administering Oracle Net Listener 9-21
Understanding Listener Redirects
9-22 Net Services Administrator's Guide
10
Configuring Oracle Connection Manager
Oracle Connection Manager is a
that forwards connection requests to
databases or other proxy servers. It operates on the session level. It usually resides on a computer separate from the database server and client computers. Oracle
Connection Manager is available for installation with Oracle Database 12c Enterprise
Edition. It is a custom installation option on the Client disk.
The primary functions of Oracle Connection Manager are:
• Access control: To use rule-based configuration to filter user-specified client requests and accept others.
• Session multiplexing: To funnel multiple client sessions through a network
destination.
Learn how to configure Oracle Connection Manager features.
•
About the cman.ora File (page 10-1)
•
Configuring Oracle Connection Manager (page 10-4)
•
Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
(page 10-8)
•
Using the Oracle Connection Manager Control Utility to Administer Oracle
(page 10-10)
•
Oracle Connection Manager Enhancements
(page 10-11)
See Also:
•
Introducing Oracle Net Services
(page 1-1) for an introduction to Oracle
Connection Manager concepts
•
Understanding the Communication Layers (page 4-1) for an architectural
overview of Oracle Connection Manager
10.1 About the cman.ora File
You configure the computer that hosts Oracle Connection Manager by setting parameters in the cman.ora
file. The cman.ora
file resides on the computer that hosts Oracle Connection Manager, and is located in the
ORACLE_HOME/network/ admin
directory. Oracle Connection Manager will not start if the cman.ora
file does not exist. This file includes the following components:
• Listening endpoint
Configuring Oracle Connection Manager 10-1
About the cman.ora File
• Access control rule list
• Parameter list
Each Oracle Connection Manager configuration is encapsulated within a single namevalue (NV) string, which consists of the preceding components.
One computer can host any number of Oracle Connection Managers, each with its own entry in the cman.ora
file. When defining more than one Oracle Connection
Manager in the file, you can assign a default by giving only one a fully qualified host name.
You can specify multiple rules for both client and Oracle Connection Manager Control utility (CMCTL) connections. The following guidelines apply when making changes:
• You must enter at least one rule for client connections and one rule for CMCTL connections. Omitting a rule results in the rejection of all connections for the rule type omitted.
• Oracle Connection Manager does not support wildcards for partial IP addresses.
If you use a wildcard, then use it in place of a full IP address. The IP address of the client may be, for example, (
SRV=*
).
• Oracle Connection Manager supports only the
/nn
notation for subnet addresses.
In Example 10-1 (page 10-2), in the first rule,
/24
represents a subnet mask that comprises 24 left-most bits. Only the first 24 bits in the client's IP address are compared with the IP address in the rule.
Note:
Oracle Connection Manager supports IPv6 addressing. See "
Connection Manager as a Bridge for IPv4 and IPv6 (page 10-8)".
(page 10-2) shows a cman.ora
file that contains a configuration entry for an Oracle Connection Manager called
CMAN1
.
Example 10-1 Sample cman.ora File
CMAN1=
(CONFIGURATION=
(ADDRESS=(PROTOCOL=tcp)(HOST=proxysvr)(PORT=1521))
(RULE_LIST=
(RULE=(SRC=192.0.2.32/24)(DST=sales-server)(SRV=*)(ACT=accept)
(ACTION_LIST=(AUT=on)(MCT=120)(MIT=30)))
(RULE=(SRC=192.0.2.32)(DST=proxysvr)(SRV=cmon)(ACT=accept)))
(PARAMETER_LIST=
(MAX_GATEWAY_PROCESSES=8)
(MIN_GATEWAY_PROCESSSES=3)))
(page 10-2) shows the following rules:
• In the first rule in the example, the following parameters are set:
–
SRC=192.0.2.32/24
is for client connections. It designates the IP address of the client, or source.
–
DST=sales-server
designates the destination host name. The ACT parameter specifies the action, that is, accept, reject, or drop. The
10-2 Oracle Database Net Services Administrator's Guide
About the cman.ora File
ACTION_LIST parameter sets attributes for a connection if it is accepted, enabling you to override default parameter settings on a connection-byconnection basis.
• In the second rule, the following parameters are set:
–
SRC=192.0.2.32
and
DST=proxysvr
represent the same server, indicating that Oracle Connection Manager and CMCTL must reside on the same computer.
See Also:
"
(page 10-5)"
Table 10-1 (page 10-3) describes the rule-level parameters in the
cman.ora
file.
Table 10-1 Rule-Level Parameters in cman.ora File
Parameter
SRC
DST
SRV
ACT
Description
The source host name or IP address of the client. The IP address can be a subnet, such as
192.0.2.62/24
.
The destination host name or IP address of the database server.
The IP address can be a subnet, such as
192.0.2.62/24
.
The service name of the Oracle database obtained from the
SERVICE_NAMES parameter in the initialization parameter file
( init.ora
).
The service name is given by the client as part of the connect descriptor when connecting to the listener. This service name is compared to the service name specified in the rule list.
To accept, reject, or drop incoming requests based on the preceding three parameters.
You can define multiple rules in the RULE_LIST. The action (
ACT
) in the first matched
RULE
is applied to the connection request. If no rules are defined, then all connections are rejected.
In the following example, client computer client1-pc
is denied access to the service sales.us.example.com
, but client
192.0.2.45
is granted access to the service db1
.
(RULE_LIST=
(RULE=(SRC=client1-pc)(DST=sales-server)(SRV=sales.us.example.com)(ACT=reject))
(RULE=(SRC=192.0.2.45)(DST=192.0.2.200)(SRV=db1)(ACT=accept)))
See Also:
Oracle Database Net Services Reference
for additional information about Oracle
Connection Manager parameters
Configuring Oracle Connection Manager 10-3
Configuring Oracle Connection Manager
10.2 Configuring Oracle Connection Manager
In order to configure Oracle Connection Manager you must configure the proxy server, database, and clients. The following tasks describe the general procedure:
Task 1 Configure the cman.ora file on the Oracle Connection Manager computer.
The cman.ora
file specifies the listening endpoint for the server, access control rules, and Oracle Connection Manager performance parameters.
"
Configuring the cman.ora file for the Oracle Connection Manager Host
(page 10-4)" explains how to perform this task.
Task 2 Configure the clients with the protocol address of the Oracle Connection
Manager listener.
"
Configuring Clients for Oracle Connection Manager (page 10-5)" explains how to
perform this task.
Task 3 Configure the database server for session multiplexing. This task is optional.
"
Configuring the Oracle Database Server for Oracle Connection Manager
(page 10-7)" explains how to perform this task.
10.2.1 Configuring the cman.ora file for the Oracle Connection Manager Host
You make changes to the cman.ora
file manually. The following procedure describes how to set parameters in the cman.ora
file:
1.
2.
3.
Navigate to the cman.ora
file in the
ORACLE_HOME/network/admin
directory.
Open the cman.ora
file with a text editor.
Configure the listening endpoint (ADDRESS).
The listening endpoint specifies the protocol address for the Oracle Connection
Manager listener. CMON, the Oracle Connection Manager monitoring process, uses this address to register information about gateway processes with the listener. The database uses the address to register service information at the
Oracle Connection Manager node.
The Oracle Connection Manager listener always listens on the TCP/IP protocol.
(ADDRESS=(PROTOCOL=tcp)(HOST=proxysvr)(PORT=1521))
Note:
Oracle Connection Manager can connect to the database using protocols such as TCP/IP (version 4 and version 6). The protocol TCPS is not supported.
4.
5.
Configure the access control rule list (RULE_LIST).
The access control rule list specifies which connections are accepted, rejected, or dropped by the listener.
Configure the parameter list (PARAMETER_LIST).
10-4 Oracle Database Net Services Administrator's Guide
Configuring Oracle Connection Manager
The parameter list sets attributes for an Oracle Connection Manager. Parameters take the following forms:
• If global, then the parameter applies to all Oracle Connection Manager connections unless a rule-level parameter overrides it. To change a global parameter default setting, enter it into the PARAMETER_LIST with an allowable value.
• If a rule-level parameter is enabled in the ACTION_LIST section of the
RULE_LIST, then it applies only to connections specified by the rule. It overrides its global counterpart.
10.2.1.1 Enabling Access Control
Use the RULE_LIST parameter to control client access to designated database servers in a TCP/IP environment. By entering filtering rules under this parameter, you can allow or restrict specific clients access to a database server.
The following procedure describes how to configure access control:
1.
2.
Open the cman.ora
file with a text editor.
Update the RULE_LIST parameter using the following format:
(RULE_LIST=
(RULE=(SRC=
source_host
)
(DST=
destination_host
)
(SRV=
service
)
(ACT=accept | reject | drop)))
See Also:
10.2.2 Configuring Clients for Oracle Connection Manager
To route clients to the database server through Oracle Connection Manager, configure the tnsnames.ora
that specifies the protocol address
of Oracle Connection Manager. This address enables clients to connect to the Oracle
Connection Manager computer. The connect descriptor looks similar to the following: sales=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=cman-pc)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=example.com)))
The following procedure describes how to configure a protocol address for Oracle
Connection Manager:
1.
Start Oracle Net Manager.
Configuring Oracle Connection Manager 10-5
Configuring Oracle Connection Manager
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
8.
In the navigator pane, select Service Naming from Directory or Local menus.
Click the plus sign (+) on the toolbar, or select Create from the Edit menu.
The Welcome page of the Net Service Name wizard appears.
Enter a name in the Net Service Name field.
Click Next.
The Protocol page appears.
Select the TCP/IP protocol for Oracle Connection Manager.
Click Next.
The Protocol Settings page appears.
Specify the Oracle Connection Manager port and protocol. The default port number for Oracle Connection Manager is 1521, and the protocol is TCP/IP.
See Also:
Oracle Database Net Services Reference
for protocol parameter settings
9.
Click Next.
The Service page appears.
10.
Enter a service name in the Service Name field, and then select the connection type.
See Also:
"
About Connect Descriptors (page 2-5)" for additional information about
setting the service name string
11.
Click Next.
Note:
Do not click Test, because a connection cannot be tested at this point.
12.
Click Finish to save your configuration and close the Net Service Name wizard.
The new network service name and the Oracle Connection Manager protocol address is added to the Service Naming folder.
10-6 Oracle Database Net Services Administrator's Guide
Configuring Oracle Connection Manager
10.2.3 Configuring the Oracle Database Server for Oracle Connection Manager
Configuring the database server involves registering database information remotely with Oracle Connection Manager and, optionally, configuring the server for multiplexing.
This section contains the following topics:
•
Configuring Service Registration for Use with Oracle Connection Manager
(page 10-7)
•
Enabling Session Multiplexing for Oracle Connection Manager (page 10-8)
10.2.3.1 Configuring Service Registration for Use with Oracle Connection Manager
To enable the database server to communicate with Oracle Connection Manager, the tnsnames.ora
file must include the service name entry, and the initialization parameter file
(init.ora)
must contain a descriptor that specifies the listening address of Oracle Connection Manager. The following procedure describes how to configure service registration:
1.
Resolve the Oracle Connection Manager alias to a service name entry in the tnsnames.ora
file as follows:
cman_listener_address
=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCL=tcp) (HOST=
proxy_server_name
)( PORT=1521))))
2.
3.
For example, the alias listener_cman
would be resolved to the following entry in the tnsnames.ora
file: listener_cman=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=proxyserver1)(PORT=1521))))
Specify an alias for Oracle Connection Manager in the init.ora
file as follows.
This alias is the one specified in the tnsnames.ora
file in step 1.
REMOTE_LISTENER=
cman_listener_address
The alias must be specified because this address is TCP, port 1521 but it is not the default local listening address of TCP, port 1521 of the database server.
For example, the alias for the Oracle Connection Manager listener running on host, proxyserver1
, specified in step 1, might look like the following in the init.ora
file:
REMOTE_LISTENER= listener_cman
After the initialization parameter file is configured with the alias of Oracle
Connection Manager, the Listener Registration (LREG) process can register database information with the Oracle Connection Manager listener. Use the following command to register the change:
SQL> ALTER SYSTEM REGISTER
Configuring Oracle Connection Manager 10-7
Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
See Also:
"
Registering Information with a Remote Listener
(page 9-5)"
10.2.3.2 Enabling Session Multiplexing for Oracle Connection Manager
To enable Oracle Connection Manager to take advantage of session multiplexing, set the DISPATCHERS parameter in the initialization parameter file ( init.ora
) with the attributes
PROTOCOL
and
MULTIPLEX
, similar to the following:
DISPATCHERS="(PROTOCOL=tcp)(MULTIPLEX=on)"
Table 10-2 (page 10-8) lists the parameters to set different levels of multiplexing.
Table 10-2 Session Multiplexing Parameters
Attribute
PROTOCOL
MULTIPLEX
Description
The network protocol for which the dispatcher generates a listening endpoint.
This parameter is used to enable session multiplexing, as follows:
• If
1
, on
, yes
,
true
, or both
is specified, then multiplexing is enabled for both incoming and outgoing network sessions.
• If in
is specified, then multiplexing is enabled for incoming network sessions from the client.
• If out
is specified, then multiplexing is enabled for outgoing network sessions.
• If
0
, off
, no
, or false
is specified, then multiplexing is disabled for both incoming and outgoing network sessions.
See Also:
•
Configuring a Shared Server Architecture (page 11-1) for additional
information about configuring shared servers
•
Oracle Database Net Services Reference
for a complete list of parameters and their default and allowed values
10.3 Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
In some database connection environments, a client and database may use different versions of the IP protocol so that complete connectivity does not exist. In this case at least two hops in the connection use different versions of the IP protocol. For example, a request passes from an IPv4 source to an IPv6 destination, from an IPv6 source to an
IPv4 destination, or from IPv6 to IPv6 through an IPv4 network.
You can use Oracle Connection Manager as a network bridge between
.
To serve as a bridge, Oracle Connection Manager must run on a dual-stack host configured with at least one IPv4 interface and at least one IPv6 interface.
Use the Oracle Connection Manager filtering feature to filter based on an IPv6 address.
You can base rules on complete or partial IP addresses. Figure 10-1 (page 10-9)
shows the format of an IPv6 address.
10-8 Oracle Database Net Services Administrator's Guide
Using Oracle Connection Manager as a Bridge for IPv4 and IPv6
Figure 10-1 IPv6 Address Format
3 13 8 24
TLA ID RES NLA ID
16
Subnet ID
64
Interface ID
The numbers at the top of the diagram indicate the number of bits in the address. Each hexadecimal character in an IPv6 address represents 4 bits. Bits 4-16 are the Top-Level
Aggregation Identifier (TLA ID) portion of the address. Bits 25-49 are the Next-Level
Aggregation Identifiers (NLA ID).
For example, in the address
2001:0db8::203:BAFF:FE0F:C74B
, the binary representation of the first four hexademical characters (
2001
) is as follows:
0010000000000001
Thus, the first 3 bits in the address are
001
. The TLA ID portion of the address is
0000000000001
.
The following procedure describes how to create a rules filter for IPv6 address:
1.
2.
3.
Navigate to the cman.ora
file located in the
ORACLE_HOME/network/admin directory.
Open the cman.ora
file with a text editor.
Create a
RULE
in the
RULE_LIST
based on IPv6 address format.
For example, assume that the source host is an IPv6-only host with address
2001:0db8::203:BAFF:FE0F:C74B
, whereas the destination is an IPv4-only host named
SALESL1593
. You configure Oracle Connection Manager as an IPv6to-IPv4 bridge by creating one of the following rules:
Type of Rule
Filter based on subnet ID
Description
Filtering is based on the
64 bits up to and including the subnet ID
Example
(RULE = (SRC =
2001:0db8::203:BAFF:FE0F:C74B/64)
(DST = SALESL1593)
(SRV = SALES)
(ACT = ACCEPT)
(ACTION_LIST = (AUT=ON)(MOCT=10)
(MIT=30)(CONN_STATE=YES))
)
Filter based on
NLA ID
Filtering is based on the
48 bits up to and including the NLA ID
(RULE = (SRC =
2001:0db8::203:BAFF:FE0F:C74B/48)
(DST = SALESL1593)
(SRV = SALES)
(ACT = ACCEPT)
(ACTION_LIST = (AUT=ON)(MOCT=10)
(MIT=30)(CONN_STATE=YES))
)
Configuring Oracle Connection Manager 10-9
Using the Oracle Connection Manager Control Utility to Administer Oracle Connection Manager
Type of Rule
Filter based on
TLA ID
Filter based on number of bits
Description
Filtering is based on the
16 bits up to and including the TLA ID
Example
(RULE = (SRC =
2001:0db8::203:BAFF:FE0F:C74B/16)
(DST = SALESL1593)
(SRV = SALES)
(ACT = ACCEPT)
(ACTION_LIST = (AUT=ON)(MOCT=10)
(MIT=30)(CONN_STATE=YES))
)
Filtering is based on the first 60 bits of the address
(RULE = (SRC =
2001:0db8::203:BAFF:FE0F:C74B/60)
(DST = SALESL1593)
(SRV = SALES)
(ACT = ACCEPT)
(ACTION_LIST = (AUT=ON)(MOCT=10)
(MIT=30)(CONN_STATE=YES))
)
See Also:
•
" About TCP/IP Protocol (page 4-7)" to learn more about IPv6
•
" About IPv6 Addresses in Connect Descriptors
(page 2-6)"
•
" Configuring Listening Protocol Addresses
(page 9-10)"
10.4 Using the Oracle Connection Manager Control Utility to Administer
Oracle Connection Manager
The Oracle Connection Manager Control utility enables you to administer Oracle
Connection Manager. When you issue commands from the operating system, the basic syntax for this utility is as follows: cmctl [command] [argument1 . . . argumentN] [-c instance_name]
In the preceding command,
-c
specifies the Oracle Connection Manager instance. You are prompted for the password if one has been set.
Caution:
There is an option to specify the password on the command line. However, this exposes the password on the screen, and is a potential security risk.
Oracle recommends not using the password option (
-p
) on the command line.
For example, the following command starts the listener, Connection Manager
Administration (CMADMIN), and gateway processes for an instance named cman1
: cmctl STARTUP -c cman1
10-10 Oracle Database Net Services Administrator's Guide
Oracle Connection Manager Enhancements
You can also issue Oracle Connection Manager utility commands at the
CMCTL prompt. To obtain the prompt, enter cmctl
with no arguments at the operating system command line. The utility may prompt for a password if Oracle Connection
Manager was installed with secure installation option. When you run
CMCTL
, the utility is started, and you can enter the necessary commands from the CMCTL prompt. The following is an example of the CMCTL prompt: cmctl
CMCTL> STARTUP
Note:
Before issuing the
STARTUP
command, do the following:
• Create the cman.ora
file. A sample file is located in the
ORACLE_HOME/ network/admin/samples
directory after installation of Oracle
Connection Manager.
• Run the
ADMINISTER
command to choose an instance to start.
See Also:
•
" Understanding Oracle Connection Manager Architecture
(page 5-6)" for an overview of the Oracle Connection Manager processes
•
Oracle Database Net Services Reference
for a complete description of Oracle
Connection Manager Control utility commands
10.5 Oracle Connection Manager Enhancements
Oracle Connection Manager proxies and screens request for Oracle Database Server.
Starting with Oracle Database 12c release 2 (12.2), Oracle Connection Manager shows the following enhancements:
• It provides a more secure access to the server by supporting SSL protocol. With this support, the database client can communicate to the server through Oracle
Connection Manager over TCPS protocol. You can also configure the Oracle
Connection Manager to have SSL connection on one side and non-SSL connection on the other side. This also acts as a secure way to hide the internal database servers for the outside clients connecting from the internet.
Multiplexing: If the gateway already has the TCPS connection to the endpoint requested by the database client, then it multiplexes the new connect request on the same connection.
• It can listen on multiple protocol addresses. With multiple listening endpoints,
Oracle Connection Manager is now able to support both TCP and TCPS at the same time. The existing single protocol address configuration is still supported.
For example:
CMAN_ALIAS=
(configuration=
(address_list=
(address=(protocol=TCP)(host=a.b.c.d)(port=12522))
(address=(protocol=TCPS)(host=a.b.c.d)(port=12523))
Configuring Oracle Connection Manager 10-11
Oracle Connection Manager Enhancements
)
..
)
• It has the addition of network data compression facility to improve network throughput and make data transfer faster between the Oracle Database Client and the Oracle Database Server. This is done in different ways according to the database client, database server, and the next hop compression ability.
Compression is enabled between any two nodes if it is negotiated by them
If more than two consecutive nodes support and negotiate compression, such case is handled in a way that the intermediate node just relays the compressed data to the next node without performing decompression.
Compression is supported between the Oracle Connection Manager and the server, even if the Oracle Database Client is earlier than the Oracle Database 12c release and cannot support compression.
• It supports up to 2 MB SDU enabling the Oracle Database Client and the Oracle
Database Server to negotiate higher SDU when establishing connection through
Oracle Connection Manager.
• Starting with this release, valid node checking for registration is enabled by default in Oracle Connection Manager. By default, only the databases on local node are allowed to register with Oracle Connection Manager. The databases on remote node can be permitted or denied to register with Oracle Connection
Manager through the use of parameters
REGISTRATION_INVITED_NODES
and
REGISTRATION_EXCLUDED_NODES
. These parameters are documented in Oracle
Database Net Services Reference
.
10-12 Oracle Database Net Services Administrator's Guide
11
Configuring a Shared Server Architecture
When client load causes a strain on memory and other system resources, database administrators can alleviate load issues by starting shared server resources. The
architecture enables a database server to allow many client processes to share very few server processes, so the number of users that can be supported is increased. With the shared server architecture, many client processes connect to a
. The dispatcher directs multiple incoming network session requests to a
common queue. An idle shared server process from a shared pool of server processes picks up a request from the queue. This means a small pool of server processes can serve a large number of clients. This is useful when a system is overloaded or has limited memory.
•
(page 11-1)
•
Enabling Session Multiplexing (page 11-3)
•
Configuring Clients for Environments with Both Shared and Dedicated Servers
(page 11-4)
See Also:
Oracle Database Administrator's Guide
for additional information about shared server configuration
11.1 About Dispatchers
Shared memory resources for dispatchers, virtual circuits, and shared servers are preconfigured enable shared servers at runtime. Database administrators can start dispatchers and shared servers with the SQL
ALTER SYSTEM
statement without having to restart the instance. When shared server mode is turned on, a dispatcher is started automatically on the TCP/IP protocol even if the DISPATCHERS parameter has not been set. Using a shared server is equivalent to setting the DISPATCHERS parameter in the database initialization parameter file as follows:
DISPATCHERS="(PROTOCOL=tcp)"
Configure the DISPATCHERS parameter directly if either of the following conditions apply:
• You need to configure a protocol other than TCP/IP.
• You want to configure one or more of the optional dispatcher attributes, such as multiplexing.
Configuring a Shared Server Architecture 11-1
About Dispatchers
You can specify the following attributes for the DISPATCHERS parameter. The
PROTOCOL
attribute is required, and the others are optional. The
ADDRESS
attribute is used to set a specify port number, such as when using a firewall.
•
ADDRESS
•
CONNECTIONS
•
DESCRIPTION
•
DISPATCHERS
•
LISTENER
•
MULTIPLEX
•
PROTOCOL
(required)
•
SERVICE
•
SESSIONS
You change the dispatcher configuration using the SQL statement
ALTER SYSTEM
.
You do not need to restart the instance after setting the parameters.
See Also:
Oracle Database Administrator's Guide
for additional information about configuring dispatchers
11.1.1 Grouping Services by Dispatcher
An Oracle database can be represented by multiple service names. A pool of dispatchers can be allocated exclusively for clients requesting a particular service. This way, the mission critical requests may be given more resources and in effect increase their priority.
For example, the following initialization parameter file shows two dispatchers. The first dispatcher services requests for clients requesting sales.us.example.com.
The other dispatcher services requests only for clients requesting adminsales.us.example.com
.
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales
DISPATCHERS="(PROTOCOL=tcp)"
DISPATCHERS="(PROTOCOL=tcp)(SERVICE=adminsales.us.example.com)"
Note:
You must manually start services on pluggable databases.
11.1.2 Monitoring Dispatchers
Use the following views to check configurations and monitor dispatchers:
11-2 Oracle Database Net Services Administrator's Guide
Enabling Session Multiplexing
• V$QUEUE: Contains information about the shared server message queues. This view is only available to the
SYS
user, and users who have
SELECT ANY TABLE system privilege, such as
SYSTEM
.
• V$DISPATCHER: Provides information about the dispatcher processes, including name, network address, status, various usage statistics, and index number.
• V$DISPATCHER_CONFIG: Provides configuration information about the dispatchers.
• V$DISPATCHER_RATE: Provides rate statistics for the dispatcher processes.
See Also:
•
Oracle Database Performance Tuning Guide
and Oracle Database Reference for additional information these views
•
Oracle Database Administrator's Guide
for additional information about shared server configuration
•
Oracle Database Reference
for additional information about configuring the
DISPATCHERS parameter and supported attributes
•
Oracle Database SQL Reference
for additional information about the
ALTER
SYSTEM
statement
11.2 Enabling Session Multiplexing
Session multiplexing, available with Oracle Connection Manager, enables multiple client sessions to funnel through a single protocol connection. For example, several client processes can connect to one dispatcher by way of a single connection from
Oracle Connection Manager.
Oracle Connection Manager allows communication by users to the dispatcher by way of a shared connection. At any one time, users might need the connection, while other client processes linked to the dispatcher by way of the connection manager process are idle. Session multiplexing is beneficial because it maximizes use of the dispatcher process connections.
Session multiplexing is also useful for database link connections between dispatchers.
The limit on the number of sessions for each dispatcher is operating system specific.
To enable session multiplexing, set the attribute
MULTIPLEX
in the DISPATCHERS parameter to on
or an equivalent value.
DISPATCHERS="(PROTOCOL=tcp)(MULTIPLEX=on)"
See Also:
"
Enabling Session Multiplexing for Oracle Connection Manager
(page 10-8)" for configuration details
Configuring a Shared Server Architecture 11-3
Configuring Clients for Environments with Both Shared and Dedicated Servers
11.3 Configuring Clients for Environments with Both Shared and
Dedicated Servers
If a shared server is configured on the server side, and a client connection request arrives when no dispatchers are registered, then the request is processed by a dedicated server process. If you want a particular client always to use a dispatcher, then configure
(SERVER=shared)
in the
CONNECT_DATA
section of the connect descriptor. For example: sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(SERVER=shared)))
If the
(SERVER=shared)
attribute is configured and a dispatcher is not available, then the client connection request is rejected, and a message is sent to the client.
If the database is configured for a shared server and a particular client requires a dedicated server, then you can configure the client to use a dedicated server in one of the following ways:
• You can configure a network service name with a connect descriptor that contains
(SERVER=dedicated)
in the
CONNECT_DATA
section. For example: sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(SERVER=dedicated)))
• You can configure the client profile file, sqlnet.ora
, with
USE_DEDICATED_SERVER=on
. This adds
(SERVER=dedicated)
to the
CONNECT_DATA
section of the connect descriptor the client uses.
Note:
If
USE_DEDICATED_SERVER
is set to
ON
, then existing
(SERVER=value) entries in connect descriptors are overwritten with
(SERVER=dedicated)
.
See Also:
•
" About the Advanced Connect Data Parameters (page 13-6)" to set the
SERVER parameter
•
" Routing Connection Requests to a Process (page 12-4)" to set the
USE_DEDICATED_SERVER parameter
•
Oracle Call Interface Programmer's Guide
and Oracle Database Administrator's
Guide
11-4 Oracle Database Net Services Administrator's Guide
12
Configuring Profiles
Learn how to configure client and server configuration parameters in profiles. A profile is a collection of parameters that specifies preferences for enabling and configuring Oracle Net features on the client or database server. A profile is stored and implemented through the sqlnet.ora
file.
•
Overview of Profile Configuration
(page 12-1)
•
Configuring the Profile During Installation
(page 12-1)
•
Understanding Client Attributes for Names Resolution
(page 12-2)
•
Settings for Database Access Control
(page 12-5)
•
About Advanced Profile Information (page 12-6)
•
Configuring External Naming Methods (page 12-10)
•
Configuring Oracle Network Security
(page 12-10)
12.1 Overview of Profile Configuration
You can use a profile to do the following:
• Specify the client domain to append to unqualified names
•
s
• Enable logging and tracing features
• Route connections through specific processes
•
•
• Use protocol-specific parameters to restrict access to the database
12.2 Configuring the Profile During Installation
Oracle Universal Installer launches
Oracle Net Configuration Assistant
installation on the client and server. Oracle Net Configuration Assistant configures the
order of the naming methods that the computer uses to resolve a
to
Configuration with the Oracle Net Configuration Assistant during installation results in an entry in the sqlnet.ora
file similar to the following:
NAMES.DIRECTORY_PATH=(ezconnect,tnsnames)
Configuring Profiles 12-1
Understanding Client Attributes for Names Resolution
The NAMES.DIRECTORY_PATH parameter specifies the priority order of the naming methods to use to resolve connect identifiers. If the installed configuration is not adequate, then use
to change the sqlnet.ora
configuration.
12.3 Understanding Client Attributes for Names Resolution
The following sections describe available client configuration options:
•
About the Default Domain for Clients
(page 12-2)
•
Prioritizing Naming Methods (page 12-3)
•
Routing Connection Requests to a Process
(page 12-4)
12.3.1 About the Default Domain for Clients
In environments where the client often requests names from a specific domain, it is appropriate to set a default domain in the client sqlnet.ora
file with the
NAMES.DEFAULT_DOMAIN parameter. This parameter is available to the local and external naming methods.
When a default domain is set, it is automatically appended to any unqualified network service name given in the connect string, and then compared to network service names stored in a tnsnames.ora
file.
For example, if the client tnsnames.ora
file contains a network service name of sales.us.example.com
, and the default domain is us.example.com
, then the user can enter the following connect string:
CONNECT scott@sales
Enter password:
password
In the preceding example, sales
gets searched as sales.us.example.com
.
If the connect string includes the domain extension, such as in
CONNECT [email protected]
, then the domain is not appended.
If a network service name in a tnsnames.ora
file is not domain qualified and the
NAMES.DEFAULT_DOMAIN parameter is set, then the network service name must be entered with a period (
.
) at the end of the name. For example, if the domain is set to us.example.com
and the client tnsnames.ora
file contains a network service name of sales2
, then the user would enter the following connect string:
CONNECT scott@sales2.
Enter password:
password
In the preceding example, the client would connect to sales2
, not sales2.us.example.com
.
12.3.1.1 Specifying a Default Domain
The following procedure describes how to specify a default domain:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
12-2 Oracle Database Net Services Administrator's Guide
Understanding Client Attributes for Names Resolution
2.
3.
4.
5.
6.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Naming.
Click the Methods tab.
In the Default Domain field, enter the domain.
Select Save Network Configuration from the File menu.
The sqlnet.ora
file should contain an entry that looks similar to the following:
NAMES.DEFAULT_DOMAIN=us.example.com
12.3.2 Prioritizing Naming Methods
After naming methods are configured, as described in
(page 8-1), they must be prioritized. Naming methods to resolve a connect identifier are tried in the order they appear in the list. If the first naming method in the list cannot resolve the connect identifier, then the second method in the list is used, and so on.
The following procedure describes how to specify the order of naming methods:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Naming.
Click the Methods tab.
Table 12-1 (page 12-3) describes the naming method values listed in the
Methods tab.
Table 12-1 Naming Method Values
Description Naming Method
Value
TNSNAMES
LDAP
EZCONNECT
Resolve a
tnsnames.ora
file on the client.
See Also:
" Configuring the Local Naming Method (page 8-7)"
Resolve a database service name, network service name, or
.
See Also:
" Configuring the Directory Naming Method
(page 8-15)"
Enable clients to use a TCP/IP connect identifier, consisting of a host name and optional port and service name, or resolve a host name alias through an existing names resolution service or centrally maintained set of
/etc/hosts
files.
See Also:
" Understanding the Easy Connect Naming Method
(page 8-1)"
Configuring Profiles 12-3
Understanding Client Attributes for Names Resolution
Table 12-1 (Cont.) Naming Method Values
Description Naming Method
Value
NIS Resolve service information through an existing network information service (NIS).
5.
6.
7.
Select naming methods from the Available Methods list, and then click the rightarrow button.
The selected naming methods move to the Selected Methods list.
Order the naming methods according to the order in which you want Oracle Net to try to resolve the network service name or database service name. Select a naming method in the Selected Methods list, and then click Promote or Demote to move the selection up or down in the list.
Select Save Network Configuration from the File menu.
The sqlnet.ora
file updates with the NAMES.DIRECTORY_PATH parameter, such as the following:
NAMES.DIRECTORY_PATH=(ldap, tnsnames)
12.3.3 Routing Connection Requests to a Process
Clients and servers can be configured so connection requests are directed to a specific process. The following procedure describes how to route connection requests to a process:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select General.
Click the Routing tab.
Select the preferred way for routing connections.
Note:
To configure all connections to use a particular server, you select the Always
Use Dedicated Server
option in Oracle Net Manager. This sets the
USE_DEDICATED_SERVER parameter in the sqlnet.ora
file to force the listener to spawn a dedicated server for all network sessions from the client.
The result is a dedicated server connection, even if a shared server is configured.
6.
Choose Save Network Configuration from the File menu.
12-4 Oracle Database Net Services Administrator's Guide
Settings for Database Access Control
See Also:
Table 12-3 (page 12-6) for a description of the fields and options
12.4 Settings for Database Access Control
You can configure the sqlnet.ora
file to allow access to some clients and deny
access to others. Table 12-2 (page 12-5) describes the available settings.
Table 12-2 Access Control Settings in sqlnet.ora
Oracle Net Manager
Field/Option
Check TCP/IP client access rights
sqlnet.ora File Parameter
TCP.VALIDNODE_CHECKIN
G
Clients excluded from access
Clients allowed access
TCP.EXCLUDED_NODES
TCP.INVITED_NODES
Description
Specify whether to screen access to the database.
If this field is selected, then Oracle Net Manager checks the parameters TCP.EXCLUDED_NODES and
TCP.INVITED_NODES to determine which clients to allow access to the database. If this field is deselected, then Oracle Net Manager does not screen clients.
Specify which clients using the TCP/IP protocol are excluded access to the database.
Specify which clients using the TCP/IP protocol are allowed access to the database.
If the TCP.INVITED_NODES parameter does not include the listener node, then the
Listener Control utility cannot connect to the listener. This will prevent start, stop and administration commands from being performed on the listener.
If there are invalid host names or IP addresses listed in the TCP.INVITED_NODES
parameter or the TCP.EXCLUDED_NODES parameter, then the Listener Control utility cannot contact the listener.
12.4.1 Configuring Database Access Control
The following procedure describes how to configure database access control:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select General.
Click the Access Rights tab.
Select the Check TCP/IP client access rights option.
In the Clients allowed to access fields and Clients excluded from access field, enter either a host name or an IP address for a client that you want to include or exclude, using commas to delimit entries placed on the same line.
Configuring Profiles 12-5
About Advanced Profile Information
12.5 About Advanced Profile Information
Table 12-3 (page 12-6) describes the advanced
sqlnet.ora
file settings that you can set.
Table 12-3 Advanced Settings in sqlnet.ora
Oracle Net Manager
Field/Option
Send operation Time
Out
Receive operation
Time Out
Connection Time
Out
sqlnet.ora File
Parameter
SQLNET.SEND_TIMEO
UT
SQLNET.RECV_TIMEO
UT
Description
Specify the time, in seconds, for a database server to complete a send operation to clients, or for clients to complete a send operation after connection establishment.
Setting this parameter is recommended for environments in which clients shut down on occasion or abnormally. If the database server cannot complete a send operation in the time specified, then it logs
ORA-12535: TNS:operation timed out
and
ORA-12608: TNS: Send timeout occurred
errors in the sqlnet.log
file.
Without this parameter, the database server continues to send responses to clients that are unable to receive data.
You can also set this parameter on the client side to specify the time, in seconds, for a client to complete send operations to the database server after connection establishment.
Without this parameter, the client may continue to send requests to a database server already overwhelmed with requests.
Specify the time, in seconds, for a database server to wait for client data after connection establishment. A client must send some data within the specified time interval.
Setting this parameter is recommended for environments in which clients shut down on occasion or abnormally. If a client does not send any data in the time specified, then the database server logs
ORA-12535: TNS:operation timed out
and
ORA-12609: TNS: Receive timeout occurred
errors to the sqlnet.log
file.
Without this parameter, the database server continues to wait for data from clients that may be down or are experiencing difficulties.
You can also use this setting on the client side to specify the time, in seconds, for a client to wait for response data from the database server after connection establishment. Without this parameter, the client may wait for a long period of time for a response from a database server overwhelmed with requests.
SQLNET.INBOUND_CO
NNECT_TIMEOUT
SEND_BUF_SIZE
Specify the time, in seconds, for a client to connect with the database server and provide the necessary authentication information.
Specify the buffer space limit for send operations of sessions.
Total Send Buffer
Size
Total Receive Buffer
Size
RECV_BUF_SIZE Specify the buffer space limit for receive operations of sessions.
12-6 Oracle Database Net Services Administrator's Guide
About Advanced Profile Information
Table 12-3 (Cont.) Advanced Settings in sqlnet.ora
Oracle Net Manager
Field/Option sqlnet.ora File
Parameter
Description
TNS Time Out Value SQLNET.EXPIRE_TIME
Specify the time interval, in minutes, to send a probe to verify that client/server connections are active. Setting a value greater than 0 ensures that connections are not left open indefinitely, due to an abnormal client termination. If the probe finds a terminated connection, or a connection that is no longer in use, then it returns an error, causing the server process to exit. This setting is intended for the database server, which typically handles multiple connections at any one time.
Limitations on using this terminated connection detection feature are:
• It is not allowed on bequeathed connections.
• Even though it is very small, the probe packet generates additional traffic that may downgrade network performance.
• Depending on which operating system is in use, the server may need to perform additional processing to distinguish the connection probing event from other events that occur. This can also result in downgrading network performance.
Client Registration
ID
SQLNET.CLIENT_REGI
STRATION
Specify a unique identifier for a client. This identifier is passed to the listener with any connection request. The identifier can be any string up to 128 characters long.
Configuring Profiles 12-7
About Advanced Profile Information
Table 12-3 (Cont.) Advanced Settings in sqlnet.ora
Oracle Net Manager
Field/Option
Logon
Authentication
Protocol Version
Turn Off UNIX
Signal Handling
sqlnet.ora File
Parameter
SQLNET.ALLOWED_LO
GON_VERSION_CLIEN
T
SQLNET.ALLOWED_LO
GON_VERSION_SERVE
R
Description
Define the minimum authentication protocol allowed when connecting to Oracle Database instances. The term in the parameter name refers to the version of the authentication protocol, not the Oracle Database release. If the client or server does not meet the minimum release specified by its partner, then authentication fails with an
ORA-28040
error.
Supported values include:
VERSION
•
12a
for Oracle Database 12c authentication protocols
(strongest protection)
•
12
for the critical patch updates CPUOct2012 and later
Oracle Database 11g authentication protocols
(recommended)
•
11
for Oracle Database 11g authentication protocols
10
for Oracle Database 10g authentication protocols
•
9
for Oracle9i Database authentication protocol
•
8
for Oracle8i Database authentication protocol
The default value is
12
or
12a
. Note the following implications of setting the value to
11
or
12
:
• The setting
SEC_CASE_SENSITIVE_LOGON=FALSE must not be used. If it is set as
FALSE
, then user accounts and secure roles become unusable. The
SEC_CASE_SENSITIVE_LOGON
initialization parameter enables or disables case sensitivity for passwords.
• To take advantage of the password protections introduced in Oracle Database 11g, users must change their passwords.
• Releases of OCI clients before Oracle Database 10g and all versions of JDBC thin clients cannot authenticate to the Oracle database using password-based authentication.
When an Oracle Database 12c server has a database link to a server running an earlier Oracle Database release, set the value of the
SQLNET.ALLOWED_LOGON_VERSION_CLIENT
parameter on the Oracle Database 12c server to match the
SQLNET.ALLOWED_LOGON_VERSION setting of the server running the earlier release.
BEQUEATH_DETACH Turn on or off UNIX signal handling.
Because the client application spawns a server process internally through the bequeath protocol as a child process, the client application becomes responsible for cleaning up the child process when it completes. When the server process completes its connection responsibilities, it becomes a terminated process. Signal handlers are responsible for cleaning up these terminated processes. Setting this parameter configures the client profile to pass this process to the UNIX initialization process by disabling signal handlers.
12-8 Oracle Database Net Services Administrator's Guide
About Advanced Profile Information
Table 12-3 (Cont.) Advanced Settings in sqlnet.ora
Description Oracle Net Manager
Field/Option
Disable Out-of-Band
Break
sqlnet.ora File
Parameter
DISABLE_OOB Turn on or off out-of-band breaks.
If deselected or set to off
, then Oracle Net can send and receive break messages using urgent data requests provided by the underlying protocol. Once enabled, this feature applies to all protocols used by this client.
If selected or set to on
, then it disables the ability to send and receive break messages using urgent data requests of the underlying protocol.
See Also:
•
" Limiting Resource Consumption by Unauthorized Users (page 14-10)"
for complete information about configuring the
SQLNET.INBOUND_CONNECT_TIMEOUT setting
•
" Configuring I/O Buffer Space (page 14-4)" for complete information
about configuring the SEND_BUF_SIZE and RECV_BUF_SIZE settings
•
Oracle Database Security Guide
for additional information about the
SQLNET.ALLOWED_LOGON_VERSION_CLIENT and
SQLNET.ALLOWED_LOGON_VERSION_SERVER settings
•
Oracle Database Net Services Reference
for additional information about the
SQLNET.ALLOWED_LOGON_VERSION_CLIENT and
SQLNET.ALLOWED_LOGON_VERSION_SERVER settings
• Oracle operating system-specific documentation to determine if the protocol supports urgent data requests. TCP/IP is an example of a protocol that supports this feature.
12.5.1 Setting the Advanced Features in the sqlnet.ora File Using Oracle Net Services
The following procedure describes how to set advanced features in the sqlnet.ora
file:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select General.
Click the Advanced tab.
Enter the values for the fields or options you want to set.
Configuring Profiles 12-9
Configuring External Naming Methods
6.
Select Save Network Configuration from the File menu.
12.6 Configuring External Naming Methods
The sqlnet.ora
file is used to configure required client parameters needed for
Network Information Service (NIS) external naming. The following procedure describes how to configure the NIS parameter in the sqlnet.ora
file:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
In the navigator pane, select Profile from the File menu.
From the list in the right pane, select Naming.
Click the External tab.
Enter
NAMES.NIS.META_MAP
in the Meta Map field.
Select Save Network Configuration from the File menu.
12.7 Configuring Oracle Network Security
Oracle network security features enable data encryption and integrity checking, enhanced authentication, and single sign-on. The features also provide centralized user management on LDAP-compliant directory servers and certificate-based single sign-on. This functionality relies on the
.
The following procedure describes how to configure a client or server to use Oracle network security features:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
In the navigator pane, select Profile from the Local menu.
From the list in the right pane, select Network Security.
Each Network Security tab page enables you to configure a separate set of parameters. The tab pages are as follows:
• Authentication: For configuration of available authentication methods, such as KERBEROS5 and RADIUS.
• Other Params: For configuration of the authentication service.
• Integrity: For configuration of the type of integrity, checksum level and available methods.
• Encryption: For configuration of the encryption type and method.
12-10 Oracle Database Net Services Administrator's Guide
Configuring Oracle Network Security
4.
5.
• SSL: For setting the use of SSL.
Select or edit options as applicable.
Select Save Network Configuration from the File menu.
See Also:
• The help button on the particular tab page
• Network security topics in the Oracle Net Manager online help. To access these topics in the online help, select Network Security, and then select the How To option
•
Oracle Database Security Guide
for additional information about configuration
Configuring Profiles 12-11
Configuring Oracle Network Security
12-12 Net Services Administrator's Guide
13
Enabling Advanced Features of Oracle Net
Services
Understand how to configure the advanced features of Oracle Net Services, including advanced connect data parameters,
,
, and connections to nondatabase services.
•
Configuring Advanced Network Address and Connect Data Information
(page 13-1)
•
Understanding Connection Load Balancing (page 13-8)
•
Configuring Transparent Application Failover (page 13-13)
•
Specifying the Instance Role for Primary and Secondary Instance Configurations
(page 13-19)
•
Understanding Static Service Registration
(page 13-21)
•
Configuring Connections to Third-party Database Services (page 13-24)
13.1 Configuring Advanced Network Address and Connect Data
Information
A database service can be accessed by several routes and protocol addresses. You configure which routes to use by setting the list of protocol addresses. You configure the order addresses are used by specifying the address parameters. This section contains the following topics:
•
Creating a List of Listener Protocol Addresses
(page 13-1)
•
About the Address List Parameters
(page 13-4)
•
About the Advanced Connect Data Parameters
(page 13-6)
13.1.1 Creating a List of Listener Protocol Addresses
A database service may be accessed by more than one network route, or protocol address. In the following example, sales.us.example.com
can connect to the sales.us.example.com
service using listeners on either sales1-server
or sales2-server
.
sales.us.example.com=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
Enabling Advanced Features of Oracle Net Services 13-1
Configuring Advanced Network Address and Connect Data Information
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
To add a network protocol address to an existing network service name or database service, use one of the following procedures:
•
Adding a Network Protocol Using Oracle Enterprise Manager Cloud Control
(page 13-2)
•
Adding a Network Protocol Using Oracle Net Manager (page 13-3)
Adding a Network Protocol Using Oracle Enterprise Manager Cloud Control
The following procedure describes how to add a network protocol to an existing network service name or database service using Oracle Enterprise Manager Cloud
Control:
1.
Access the Directory Naming or Local Naming page in Oracle Enterprise Manager
Cloud Control:
a.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
b.
c.
Select Local Naming or Directory Naming from the Administer list, and then select the Oracle home for the directory server or the location of the local configuration files.
Click Go.
The Local Naming or Directory Naming page appears.
Select the directory service or network service name.
• For Local Naming, select a network service from the list, and then click Edit.
• For Directory Naming, perform a search of the network service name in the
Simple Search section, then select the network service or database service from the Results list, and then click Edit.
In the Addresses section, click Add.
The Add Address page appears.
From the Protocol list, select the protocol which the listener is configured to listen.
This protocol must also be installed on the client.
Enter the appropriate parameter information for the selected protocol in the fields provided.
See Also:
Oracle Database Net Services Reference
for protocol parameter settings
13-2 Oracle Database Net Services Administrator's Guide
Configuring Advanced Network Address and Connect Data Information
6.
(Optional) In the Advanced Parameters section, specify the I/O buffer space limit for send and receive operations of sessions in the Total Send Buffer Size and Total
Receive Buffer Size fields.
See Also:
"
Configuring I/O Buffer Space (page 14-4)" for additional information about
buffer space
7.
8.
Click OK.
The protocol address is added to the Addresses section.
Click OK to update the address information.
Adding a Network Protocol Using Oracle Net Manager
The following procedure describes how to add a network protocol to an existing network service name or database service using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
In the navigator pane, select Service Naming from the Directory or Local menus.
Select either the network service name or a database service.
The right pane displays the current destination service and address list.
In the Address Configuration box, click the plus sign (+) to add a new address.
A new Address tab appears:
a.
Select the protocol and enter appropriate address information.
See Also:
Oracle Database Net Services Reference
for details about protocol address parameters
b.
(Optional) On the Address tab, click Advanced to specify the I/O buffer space limit for send and receive operations of sessions in the Total Send
Buffer Size and Total Receive Buffer Size fields.
See Also:
"
Configuring I/O Buffer Space (page 14-4)" for additional information about
buffer space
c.
Order the protocol addresses using the left-arrow and right-arrow buttons.
This will order the addresses in the protocol address list. Unless multiple address options are configured, the first address in the list is contacted.
Enabling Advanced Features of Oracle Net Services 13-3
Configuring Advanced Network Address and Connect Data Information
5.
Select Save Network Configuration from the File menu.
13.1.2 About the Address List Parameters
When a database service is accessible by multiple listener protocol addresses, specify the order in which the addresses are to be used, such as chosen randomly or tried
(page 13-4) lists the parameters used with multiple protocol addresses.
Table 13-1 Address List Parameters in the tnsnames.ora File
Parameter
FAILOVER
LOAD_BALANCE
SOURCE_ROUTE
Description
At connect time, this parameter instructs Oracle Net to fail over to a different listener if the first listener fails when set to on
. The number of addresses in the list determines how many addresses are tried. When set to off
, instructs Oracle Net to try one address.
Connect-time failover is turned on
by default for multiple address lists (ADDRESS_LIST), connect descriptors (DESCRIPTION), and multiple connect descriptors (DESCRIPTION_LIST).
When set to on
, this parameter instructs Oracle Net to progress through the list of protocol addresses in a random sequence, balancing the load on the various listeners. When set to off
, instructs Oracle Net to try the addresses sequentially until one succeeds.
Client load balancing is turned on
by default for multiple connect descriptors (DESCRIPTION_LIST).
When set to on
, this parameter instructs Oracle Net to use each address in the order presented until the destination is reached. This parameter is required for reaching the destination using a specific route, that is, by specific computers. This parameter is used to
.
Note:
You cannot set source routing (SOURCE_ROUTE) at the same level as connect-time failover (FAILOVER) or client load balancing
(LOAD_BALANCE). Source routing connects to each address in the list sequentially whereas connect-time failover and client load balancing select a single address from a list.
When a connect descriptor in a
tnsnames.ora
file contains at least two protocol addresses for an Oracle Connection Manager hop, then parameters for connect-time failover and load balancing within the hop can be included in the file.
Table 13-2 (page 13-4) describes the address list options.
Table 13-2 Address List Options Dialog Box
Option
Try each address, in order, until one succeeds.
Parameter Setting
FAILOVER=on
13-4 Oracle Database Net Services Administrator's Guide
Configuring Advanced Network Address and Connect Data Information
Table 13-2 (Cont.) Address List Options Dialog Box
Option
Try each address, randomly, until one succeeds.
Try one address, selected at random.
Use each address in order until destination reached.
Use only the first address.
Parameter Setting
LOAD_BALANCE=on
FAILOVER=on
LOAD_BALANCE=on
SOURCE_ROUTE=on
LOAD_BALANCE=off
FAILOVER=off
SOURCE_ROUTE=off
The following example shows a tnsnames.ora
file configured for client load balancing: sales.us.example.com=
(DESCRIPTION=
(ADDRESS_LIST=
(LOAD_BALANCE=on)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
The following example shows a tnsnames.ora
file configured for connect-time failover: sales.us.example.com=
(DESCRIPTION=
(ADDRESS_LIST=
(LOAD_BALANCE=off)
(FAILOVER=on)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
The following example shows a tnsnames.ora file configured for Oracle Connection
Manager and load balancing: sales.us.example.com=
(DESCRIPTION=
(SOURCE_ROUTE=ON)
(ADDRESS=(PROTOCOL=tcp)(HOST=cman-pc1)(PORT=1630))
(ADDRESS=
(LOAD_BALANCE=ON)
(ADDRESS=(PROTOCOL=tcp)(HOST=cman-pc2)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=cman-pc3)(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
See Also:
"
Configuring Clients for Oracle Connection Manager (page 10-5)" for
additional information about configuring clients for source routing
Enabling Advanced Features of Oracle Net Services 13-5
Configuring Advanced Network Address and Connect Data Information
13.1.2.1 Configuring Address List Parameters
The following procedure describes how to configure address list parameters:
1.
2.
Perform the procedure in " Creating a List of Listener Protocol Addresses
(page 13-1)".
Use Oracle Enterprise Manager Cloud Control or Oracle Net Manager to configure address list options.
• For Oracle Enterprise Manager Cloud Control, select the appropriate option in the Connect-time Failover and Client Load Balancing section.
• For Oracle Net Manager, click Advanced in the Address Configuration box.
The Address List Options dialog box appears. Select the appropriate option.
13.1.3 About the Advanced Connect Data Parameters
Starting with Oracle Database 12c release 2 (12.2), data compression can be set in the sqlnet.ora
file. The parameters that set compression are SQLNET.COMPRESSION
and SQLNET.COMPRESSION_LEVELS. Setting these parameters in the sqlnet.ora
file affects all the connections using the sqlnet.ora
file, except for Oracle Data
Guard streaming redo and SecureFiles LOBs (Large Objects). The following example shows how to set compression:
SQLNET.COMPRESSION = yes
SQLNET.COMPRESSION_LEVELS =(low,high)
The CONNECT_DATA section of a connect descriptor in the tnsnames.ora
file defines the destination database service. In the following example, SERVICE_NAME defines a service called sales.us.example.com
: sales.us.example.com=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
In addition to the service name, you can optionally configure the connect data
information with the parameters described in Table 13-3 (page 13-6).
Table 13-3 Advanced Connect Data Settings in the tnsnames.ora File
Oracle Enterprise
Manager Cloud
Control/Oracle Net
Manager Option
Instance Name
tnsnames.ora File
Parameter
INSTANCE_NAME
Description
Session Data Unit
Size
SDU
The database instance to access. The instance name can be obtained from the INSTANCE_NAME parameter in the initialization parameter file.
The transfer rate of data packets being sent across the network.
You can specify the
performance characteristics having to do with the packets sent across the network. The SDU size limit is 2 MB.
13-6 Oracle Database Net Services Administrator's Guide
Configuring Advanced Network Address and Connect Data Information
Table 13-3 (Cont.) Advanced Connect Data Settings in the tnsnames.ora File
Description Oracle Enterprise
Manager Cloud
Control/Oracle Net
Manager Option
Use for
Heterogeneous
Services
Oracle RDB
Database
Type of Service
Global Database
Name
tnsnames.ora File
Parameter
HS
RDB_DATABASE
TYPE_OF_SERVICE
GLOBAL_NAME
If you want an Oracle database server to access a third-party
, then set this option to on
.
The file name of the Oracle Rdb database.
The type of service to use for the Oracle Rdb database.
Oracle Rdb database identifier.
In the following example, the transfer rate for data packets is set: sales.us.example.com=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(SDU=8192)
))
Use Oracle Enterprise Manager Cloud Control or Oracle Net Manager to configure advanced CONNECT_DATA parameters for either a network service name or a database service.
Configuring Advanced Connect Descriptor Parameters Using Oracle Enterprise
Manager Cloud Control
The following procedure describes how to configure advanced connect descriptor parameters using Oracle Enterprise Manager Cloud Control:
1.
Access the Directory Naming or Local Naming page in Oracle Enterprise Manager
Cloud Control, as follows:
a.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
b.
c.
Select Local Naming or Directory Naming from the Administer list, and then select the Oracle home for the directory server or the location of the local configuration files.
Click Go.
The Directory Naming or Local Naming pages appear.
Select the directory service or network service name.
Enabling Advanced Features of Oracle Net Services 13-7
Understanding Connection Load Balancing
3.
4.
5.
• For Local Naming, select a network service from the list, and then click Edit.
• For Directory Naming, search the network service name in the Simple Search section by selecting the network service or database service from the Results list, and then clicking Edit.
Click the Advanced tab.
Enter fields or select options as appropriate, and then click OK.
Click OK to update the connect data information.
Configuring Advanced Connect Descriptor Parameters Using Oracle Net
Manager
The following procedure describes how to configure advanced connect descriptor parameters using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
In the navigator pane, select Service Naming from Directory or Local menus.
Select either the network service name or a database service.
The right pane displays the current destination service and address list.
In the Service Identification box, click Advanced.
The Advanced Service Options dialog box appears.
Enter fields or select options as appropriate, and then click OK.
If you are making these changes to the Local folder, then select Save Network
Configuration
from the File menu. Changes to the Directory folder are saved automatically.
13.2 Understanding Connection Load Balancing
The
feature improves connection performance by
balancing the number of active connections among multiple
Real Application Clusters (Oracle RAC)
environment, connection load balancing can also balance the number of active connections among multiple instances.
Because the Listener Registration (LREG) process can register with remote listeners, a listener can always be aware of all instances and dispatchers, regardless of their location. Depending on the load information, a listener decides which instance and, if shared server is configured, which dispatcher to send the incoming client request.
In a
configuration, a listener selects a dispatcher in the following order:
1.
2.
3.
Least loaded node.
Least loaded instance.
Least loaded dispatcher for that instance.
13-8 Oracle Database Net Services Administrator's Guide
Understanding Connection Load Balancing
In a
configuration, a listener selects an instance in the following
order:
1.
Least loaded node.
2.
Least loaded instance.
Load Balancing across nodes for HTTP presentation is introduced in this release. The remote listener can load balance across instances that are on different nodes for HTTP presentation using HTTP redirect.
An Oracle RAC environment requires that the dispatchers on each instance be crossregistered with the other listeners on the other nodes. This is achieved by the use of the
LISTENER
attribute of the DISPATCHERS parameter.
Note:
For optimum connection load balancing results, the instances that belong to the same database service should be on equivalent hardware and software configurations.
See Also:
•
" Registering Information with a Remote Listener
(page 9-5)" for additional information about cross-registration
•
Oracle Database Reference
for complete information about the
SERVICE_NAMES and INSTANCE_NAME parameters
•
Configuring a Shared Server Architecture (page 11-1) for additional
information about the
LISTENER
attribute
•
Oracle Database Global Data Services Concepts and Administration Guide
for information about management of global services
13.2.1 Example of Connection Load Balancing for Shared Server Configuration
(page 13-10) shows an Oracle RAC shared server database with two instances, sales1
and sales2
, of the same service, sales.us.example.com
. The instances sales1
and sales2
reside on computers sales1-server
and sales2server
, respectively. Instance sales1
has one dispatcher and instance sales2
has two dispatchers. Listeners named listener
run on nodes 1 and 2. The listener attribute in the DISPATCHERS parameter has been configured to allow for service registration of information to both listeners.
Enabling Advanced Features of Oracle Net Services 13-9
Understanding Connection Load Balancing
Figure 13-1 Load Balancing Environment for a Shared Server Configuration
sales1-server sales2-server
Listener Listener sales1 dispatcher1 sales2 dispatcher2 dispatcher3
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales1
DISPATCHERS=(PROTOCOL=tcp)
(DISPATCHERS=1) (LISTENER=listeners_sales)
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales2
DISPATCHERS=(PROTOCOL = tcp)
(DISPATCHERS=2) (LISTENER=listeners_sales)
In this example, sales2-server
is the least loaded node, sales2
is the least loaded instance, and dispatcher2
is the least loaded dispatcher. The following load information is registered.
• The one minute load average for each instance is 600 for sales1
and 400 for sales2
. This can happen if more processing is required on sales1-server
.
• The number of connections to each instance is 200 for sales1
and 300 for sales2
.
• The number of dispatcher connections to each instance is 200 for dispatcher1
,
100 for dispatcher2
, and 200 for dispatcher3
.
• The number of connections to sales1
(200) is the same as that of its only dispatcher, dispatcher1
.
• The number of connections on sales2
(300) is the sum of the connections on its two dispatchers, dispatcher2
(100) and dispatcher3
(200).
The listeners_sales
value in
(LISTENER=listeners_sales)
is resolved through a local tnsnames.ora
file on both servers as follows: listeners_sales=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521))))
13-10 Oracle Database Net Services Administrator's Guide
Understanding Connection Load Balancing
Based on the environment, the following actions occur. The numbered actions correspond to the arrows shown in
(page 13-11):
1.
2.
LREG processes for instances sales1
and sales2
register with both listeners.
The listeners are updated dynamically on the load of the instances and dispatchers.
The client sends a connect request. A connect descriptor is configured to try each protocol address randomly until one succeeds: sales.us.example.com=
(DESCRIPTION=
(
LOAD_BALANCE=on
)
(
FAILOVER=on
)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))
3.
4.
The listener on sales1-server
was randomly chosen to receive the client connect request.
The listener on sales1-server
compares the load of the instances sales1
and sales2
. The comparison takes into account the load on nodes sales1-server and sales2-server
, respectively. Because sales2-server
is less loaded than sales1-server
, the listener selects sales2-server
over sales1-server
.
The listener compares the load on dispatchers dispatcher2
and dispatcher3
.
Because dispatcher2
is less loaded than dispatcher3
, the listener redirects the client connect request to dispatcher2
.
The client connects directly to dispatcher2
.
Figure 13-2 Load Balancing Example for a Shared Server Configuration
sales1
2 dispatcher1
Listener
3
Client
CONNECT scott@ sales.us.example.com
4
1 sales2 sales.us.example.com
dispatcher2 dispatcher3
Listener
13.2.2 Example of Connection Load Balancing for Dedicated Server Configuration
(page 13-12) shows an Oracle RAC dedicated server database with two instances, sales1
and sales2
, of the same service, sales.us.example.com
. The instances sales1
and sales2
reside on computers sales1-server
and sales2server
, respectively. Listeners named listener
run on nodes 1 and 2. The
Enabling Advanced Features of Oracle Net Services 13-11
Understanding Connection Load Balancing
REMOTE_LISTENER initialization parameter has been configured to allow for service registration of information to both listeners.
Figure 13-3 Load Balancing Environment for a Dedicated Server Configuration
sales1-server sales2-server
Listener Listener sales1 sales2
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales1
REMOTE_LISTENER=listener_sales2
SERVICE_NAMES=sales.us.example.com
INSTANCE_NAME=sales2
REMOTE_LISTENER=listener_sales1
In this example, the following load information is registered:
• sales1-server
has a node load average of 450 per minute.
• sales2-server
has a node load average of 200 per minute.
• sales1
has 200 connections.
• sales2
has 150 connections.
The listener_sales1
value in
(REMOTE_LISTENER=listener_sales1)
is resolved through a local tnsnames.ora
file on the sales2-server
as follows: listener_sales1=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)))
The listener_sales2
value in
(REMOTE_LISTENER=listener_sales2)
is resolved through a local tnsnames.ora
file on the sales1-server
as follows: listener_sales2=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
Based on the environment, the following actions occur. The numbered actions correspond to the arrows shown in
(page 13-13):
1.
LREG processes for instances sales1
and sales2
register with both listeners.
The listeners are dynamically updated on the load of the instances.
13-12 Oracle Database Net Services Administrator's Guide
Configuring Transparent Application Failover
2.
3.
4.
Based on the preceding information, sales2-server
is the least loaded node and sales2
is the least loaded instance.
The client sends a connect request.
A connect descriptor is configured to try each protocol address randomly until one succeeds: sales.us.example.com=
(DESCRIPTION=
(ADDRESS_LIST=
(
LOAD_BALANCE=on
)
(FAILOVER=on)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))
The listener on sales1-server
was randomly chosen to receive the client connect request.
The listener on sales1-server
compares the load of the instances sales1
and sales2
. The comparison takes into account the load on nodes sales1-server and sales2-server
, respectively. Because sales2-server
is less loaded than sales1-server
, the listener selects sales2-server
over sales1-server
.
The listener on sales1-server
redirects the client connect request to the listener on sales2-server
.
The client connects to the listener on sale2-server
. The listener starts a dedicated server process, and the dedicated server process inherits the connection request from the listener.
Figure 13-4 Load Balancing Example for a Dedicated Server Configuration
1 sales1
2
Listener
3
Client
CONNECT scott@ sales.us.example.com
sales.us.example.com
1 sales2
4
Listener
Dedicated
Server
Process
13.3 Configuring Transparent Application Failover
Transparent Application Failover (TAF) instructs Oracle Net to fail over a failed connection to a different listener. This enables the user to continue to work using the new connection as if the original connection had never failed.
Enabling Advanced Features of Oracle Net Services 13-13
Configuring Transparent Application Failover
TAF involves manual configuration of a network service name that includes the
FAILOVER_MODE parameter included in the CONNECT_DATA section of the connect descriptor.
This section contains the following topics:
•
About Transparent Application Failover
(page 13-14)
•
What Transparent Application Failover Restores
(page 13-14)
•
About the FAILOVER_MODE Parameters
(page 13-15)
•
Implementing Transparent Application Failover (page 13-16)
•
Verifying Transparent Application Failover
(page 13-18)
13.3.1 About Transparent Application Failover
TAF is a client-side feature that allows clients to reconnect to surviving databases in the event of a failure of a database instance. Notifications are used by the server to trigger TAF callbacks on the client-side.
TAF is configured using either client-side specified TNS (Transparent Network
Substrate) connect string or using server-side service attributes. If both methods are used to configure TAF, then the server-side service attributes supersede the client-side settings. Server-side service attributes are the preferred way to set up TAF.
TAF can operate in one of two modes, Session Failover and Select Failover. Session
Failover re-creates lost connections and sessions. Select Failover replays queries that were in progress.
When there is a failure, callback functions are initiated on the client-side using Oracle
Call Interface (OCI) callbacks. This works with standard OCI connections as well as connection pool and session pool connections.
TAF operates with Oracle Data Guard to provide automatic failover. TAF works with the following database configurations to effectively mask a database failure:
• Oracle Real Application Clusters
• Replicated systems
• Standby databases
• Single instance Oracle database
See Also:
•
Oracle Real Application Clusters Administration and Deployment Guide
•
Oracle Call Interface Programmer's Guide
for more details on callbacks, and session pools
13.3.2 What Transparent Application Failover Restores
TAF automatically restores some or all of the following elements associated with active database connections. Other elements may need to be embedded in the application code to enable TAF to recover the connection.
13-14 Oracle Database Net Services Administrator's Guide
Configuring Transparent Application Failover
• Client-server database connections: TAF automatically reestablishes the connection using the same connect string or an alternate connect string that you specify when configuring failover.
• Users' database sessions: TAF automatically logs a user in with the same user ID as was used before the failure. If multiple users were using the connection, then
TAF automatically logs them in as they attempt to process database commands.
Unfortunately, TAF cannot automatically restore other session properties. These properties can be restored by invoking a callback function.
• Completed commands: If a command was completed at the time of connection failure, and it changed the state of the database, then TAF does not resend the command. If TAF reconnects in response to a command that may have changed the database, then TAF issues an error message to the application.
• Open cursors used for fetching: TAF allows applications that began fetching rows from a cursor before failover to continue fetching rows after failover. This is called select failover. It is accomplished by re-running a
SELECT
statement using the same snapshot, discarding those rows already fetched and retrieving those rows that were not fetched initially. TAF verifies that the discarded rows are those that were returned initially, or it returns an error message.
• Active transactions: Any active transactions are rolled back at the time of failure because TAF cannot preserve active transactions after failover. The application instead receives an error message until a
ROLLBACK
command is submitted.
• Server-side program variables: Server-side program variables, such as PL/SQL package states, are lost during failures, and TAF cannot recover them. They can be initialized by making a call from the failover callback.
See Also:
Oracle Call Interface Programmer's Guide
13.3.3 About the FAILOVER_MODE Parameters
The FAILOVER_MODE parameter must be included in the CONNECT_DATA section of a connect descriptor. The FAILOVER_MODE parameter can contain the parameters described in
Table 13-4 Additional Parameters of the FAILOVER_MODE Parameter
FAILOVER_MODE
Parameters
BACKUP
Description
DELAY
A different network service name for backup connections. A backup should be specified when using preconnect
to pre-establish connections.
The amount of time in seconds to wait between connect attempts. If
RETRIES is specified, then DELAY defaults to one second.
If a callback function is registered, then this parameter is ignored.
Enabling Advanced Features of Oracle Net Services 13-15
Configuring Transparent Application Failover
Table 13-4 (Cont.) Additional Parameters of the FAILOVER_MODE Parameter
FAILOVER_MODE
Parameters
METHOD
Description
RETRIES
The setting for fast failover from the primary node to the backup node:
• basic
: Set to establish connections at failover time. This option requires almost no work on the backup server until failover time.
• preconnect
: Set to pre-established connections. This provides faster failover but requires that the backup instance be able to support all connections from every supported instance.
The number of times to attempt to connect after a failover. If DELAY is specified, then RETRIES defaults to five retry attempts.
If a callback function is registered, then this parameter is ignored.
TRANSACTION
TYPE
The ability for a transaction to complete after a recoverable database error. This parameter is set using the SRVCTL utility or the
DBMS_SERVICE package.
This parameter is used with
COMMIT_OUTCOME=TRUE
.
The type of failover. Three types of Oracle Net failover functionality are available by default to Oracle Call Interface (OCI) applications:
• session
: Set to fail over the session. If the user's connection is lost, then a new session is automatically created for the user on the backup. This type of failover does not attempt to recover select operations.
• select
: Set to enable users with open cursors to continue fetching on them after failure. However, this mode involves overhead on the client side in normal select operations.
• none
: This is the default. No failover functionality is used. This can also be explicitly specified to prevent failover from happening.
Note:
Oracle Net Manager does not provide support for TAF parameters. These parameters must be set manually.
13.3.4 Implementing Transparent Application Failover
Depending on the FAILOVER_MODE parameters, you can implement TAF in several ways. Oracle recommends the following methods:
•
TAF with Connect-Time Failover and Client Load Balancing
(page 13-17)
•
TAF Retrying a Connection (page 13-17)
•
TAF Pre-establishing a Connection (page 13-17)
Important:
Do not set the GLOBAL_DBNAME parameter in the SID_LIST_listener_name section of the listener.ora
file. A statically configured global database name disables TAF.
13-16 Oracle Database Net Services Administrator's Guide
Configuring Transparent Application Failover
13.3.4.1 TAF with Connect-Time Failover and Client Load Balancing
Implement TAF with connect-time failover and client load balancing for multiple addresses. In the following example, Oracle Net connects randomly to one of the protocol addresses on sales1-server
or sales2-server
. If the instance fails after the connection, then the TAF application fails over to the other node's listener, reserving any
SELECT
statements in progress.
sales.us.example.com=
(DESCRIPTION=
(LOAD_BALANCE=on)
(FAILOVER=on)
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(FAILOVER_MODE=
(TYPE=select)
(METHOD=basic))))
Although the preceding example has multiple addresses, the
ADDRESS_LIST parameter was not used. This is because the
ADDRESS_LIST
parameter is not mandatory.
13.3.4.2 TAF Retrying a Connection
TAF also provides the ability to automatically retry connecting if the first connection attempt fails with the RETRIES and DELAY parameters. In the following example,
Oracle Net tries to reconnect to the listener on sales1-server
. If the failover connection fails, then Oracle Net waits 15 seconds before trying to reconnect again.
Oracle Net attempts to reconnect up to 20 times.
sales.us.example.com=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(FAILOVER_MODE=
(TYPE=select)
(METHOD=basic)
(RETRIES=20)
(DELAY=15))))
13.3.4.3 TAF Pre-establishing a Connection
A backup connection can be pre-established. The initial and backup connections must be explicitly specified. In the following example, clients that use network service name sales1.us.example.com
to connect to the listener on sales1-server
are also preconnected to sales2-server
. If sales1-server
fails after the connection, then
Oracle Net fails over to sales2-server
, preserving any
SELECT
statements in
Enabling Advanced Features of Oracle Net Services 13-17
Configuring Transparent Application Failover progress. Similarly, Oracle Net preconnects to sales1-server
for those clients that use sales2.us.example.com
to connect to the listener on sales2-server
.
sales1.us.example.com=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_NAME=sales1)
(FAILOVER_MODE=
(BACKUP=sales2.us.example.com)
(TYPE=select)
(METHOD=preconnect)))) sales2.us.example.com=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_NAME=sales2)
(FAILOVER_MODE=
(BACKUP=sales1.us.example.com)
(TYPE=select)
(METHOD=preconnect))))
13.3.5 Verifying Transparent Application Failover
You can query the FAILOVER_TYPE, FAILOVER_METHOD, and FAILED_OVER columns in the V$SESSION view to verify that TAF is correctly configured. To view the columns, use a query similar to the following:
SELECT MACHINE, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER, COUNT(*)
FROM V$SESSION
GROUP BY MACHINE, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER;
The output before failover looks similar to the following:
MACHINE FAILOVER_TYPE FAILOVER_METHOD FAILED_OVER COUNT(*)
-------------------- ------------- ---------- --- ---------sales1 NONE NONE NO 11 sales2 SELECT PRECONNECT NO 1
The output after failover looks similar to the following:
MACHINE FAILOVER_TYPE FAILOVER_METHOD FAILED_OVER COUNT(*)
-------------------- ------------- ---------- --- ---------sales2 NONE NONE NO 10 sales2 SELECT PRECONNECT YES 1
Note:
You can monitor each step of TAF using an appropriately configured
OCI
TAF CALLBACK
function.
13-18 Oracle Database Net Services Administrator's Guide
Specifying the Instance Role for Primary and Secondary Instance Configurations
See Also:
•
Oracle Call Interface Programmer's Guide
•
Oracle Database Reference
for additional information about the V$SESSION view
13.4 Specifying the Instance Role for Primary and Secondary Instance
Configurations
The INSTANCE_ROLE parameter is an optional parameter for the CONNECT_DATA section of a connect descriptor. It enables you to specify a connection to the primary or secondary instance of Oracle RAC configurations.
This parameter is useful when:
• You want to explicitly connect to a primary or secondary instance. The default is the primary instance.
• You want to use TAF to preconnect to a secondary instance.
Table 13-5 (page 13-19) describes the INSTANCE_ROLE parameters.
Table 13-5 INSTANCE_ROLE Parameters
Description INSTANCE_ROLE
Parameter
PRIMARY
SECONDARY
ANY
Specifies a connection to the primary instance.
Specifies a connection to the secondary instance.
Specifies a connection to whichever instance has the lowest load, regardless of primary or secondary instance role.
Connection to Instance Role Type
In the following example of the tnsnames.ora
file, network service name sales_primary
enables connections to the primary instance, and network service name sales_secondary
enables connections to the secondary instance.
sales_primary=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=primary))) sales_secondary=
(DESCRIPTION=
Enabling Advanced Features of Oracle Net Services 13-19
Specifying the Instance Role for Primary and Secondary Instance Configurations
(ADDRESS_LIST=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=secondary)))
Connection to a Specific Instance
There are times when Oracle Enterprise Manager Cloud Control and other system management products need to connect to a specific instance regardless of its role to perform administrative tasks. For these types of connections, configure
(
INSTANCE_NAME=instance_name)
and (
INSTANCE_ROLE=any)
to connect to the instance regardless of its role.
In the following example, network service name sales1
enables connections to the instance on sales1-server
and sales2
enables connections to the instance on sales2-server
.
(SERVER=dedicated)
is specified to force a dedicated server connection.
sales1=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=any)
(INSTANCE_NAME=sales1)
(SERVER=dedicated)
)) sales2=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=any)
(INSTANCE_NAME=sales2)
(SERVER=dedicated)
))
Note:
Failover is incompatible with the preceding settings.
TAF Pre-establishing a Connection
If TAF is configured, then a backup connection can be pre-established to the secondary instance. The initial and backup connections must be explicitly specified. In the following example, Oracle Net connects to the listener on sales1-server
and preconnects to sales2-server
, the secondary instance. If sales1-server
fails
13-20 Oracle Database Net Services Administrator's Guide
Understanding Static Service Registration after the connection, then the TAF application fails over to sales2-server
, the secondary instance, preserving any
SELECT
statements in progress.
sales1.example.com=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales1-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=primary)
(FAILOVER_MODE=
(BACKUP=sales2.example.com)
(TYPE=select)
(METHOD=preconnect))
)) sales2.example.com=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=sales2-server)
(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)
(INSTANCE_ROLE=secondary)))
13.5 Understanding Static Service Registration
The listener uses the dynamic service information about the database and instance before using statically configured information in the listener.ora
file.
Configuration of static service information is necessary in the following cases:
• Use of external procedure calls
• Use of Oracle Heterogeneous Services
• Use of Oracle Data Guard
• Remote database startup from a tool other than Oracle Enterprise Manager Cloud
Control
• Connections to Oracle databases earlier than Oracle8i release 2 (8.1)
(page 13-21) shows a listener.ora file configured for static service registration. The LISTENER entry defines the listening protocol address for a listener named Listener, and the SID_LIST_LISTENER entry provides information about the external services statically supported by the Listener listener.
Example 13-1 Example listener.ora File
LISTENER=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc) (queuesize=50))))
SID_LIST_listener=
(SID_LIST=
(SID_DESC=
(SID_NAME=plsextproc)
(ORACLE_HOME=/oracle8)
(PROGRAM=extproc)))
Enabling Advanced Features of Oracle Net Services 13-21
Understanding Static Service Registration
The SID_LIST_listener_name parameter setting in the listener.ora
file specifies information about the databases served by the listener. When services are configured statically, a listener starts a dedicated server process when it receives a client request.
If the instance is not up, then the server returns an
Oracle not available
error message.
If a database cannot find the listener, then configure the listener.ora
file with the
GLOBAL_DBNAME parameter, as shown in the following example
SID_LIST_listener=
(SID_LIST=
(SID_DESC=
(
GLOBAL_DBNAME
=sales.example.com)
(SID_NAME=sales)
(ORACLE_HOME=/u01/app/oracle))
Note:
A statically-configured global database name disables TAF. To use TAF, do not set the GLOBAL_DBNAME parameter in the SID_LIST_listener_name section of the listener.ora
file.
Table 13-6 (page 13-22) describes static service settings in the
listener.ora
file.
Table 13-6 Static Service Settings in listener.ora
Oracle Net
Manager Field
SID
Service Name
listener.ora File
Parameter
SID_NAME
Description
The
Oracle system identifier (SID)
of the instance. You can obtain the SID value from the INSTANCE_NAME parameter in the initialization parameter file.
GLOBAL_DBNAME The database service.
While processing a client connection request, the listener tries to match the value of this parameter with the value of the
SERVICE_NAME parameter in the client connect descriptor. If the client connect descriptor uses the SID parameter, then the listener does not attempt to map the values. This parameter is primarily intended for configurations with Oracle8 databases (where dynamic service registration is not supported for dedicated servers). This parameter may also be required for use with Oracle8i and later database services by some configurations.
The value for this parameter is typically obtained from the combination of the DB_NAME and DB_DOMAIN parameters
(DB_NAME.DB_DOMAIN) in the initialization parameter file, but the value can also contain any valid name used by clients to identify the service.
When using a connect descriptor with a SERVICE_NAME parameter, ensure that any SID_DESC entry does not have the value
GLOBAL_DBNAME
.
13-22 Oracle Database Net Services Administrator's Guide
Understanding Static Service Registration
Table 13-6 (Cont.) Static Service Settings in listener.ora
Oracle Net
Manager Field
Oracle Home
Directory
Not applicable
listener.ora File
Parameter
ORACLE_HOME
Description
SID_LIST_listener_na
me
The Oracle home location of the instance. Without this setting, the listener assumes its Oracle home for the instance.
On Linux and UNIX, this setting is optional.
On Microsoft Windows, this setting is ignored. The Oracle home specified by the ORACLE_HOME parameter in
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\HOMEID
of the
Microsoft Windows registry is used.
The section of the listener.ora
file that defines the database served by the listener.
13.5.1 Configuring Static Registration for the Listener
The following procedure describes how to statically configure the listener:
Note:
If you are using connect-time failover or TAF, such as in an Oracle Real
Application Clusters environment, then do not set the GLOBAL_DBNAME parameter.
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
6.
Select Listeners from the Administer list, and then select the Oracle home that contains the configuration files.
Click Go. You may be prompted to log in to the database server.
The Listeners page appears.
Select a listener, and then click Edit.
The Edit Listener page appears.
Click the Static Database Registration tab, and then click Add.
The Add Database Service page appears. Enter the required information in the fields.
Click OK.
Enabling Advanced Features of Oracle Net Services 13-23
Configuring Connections to Third-Party Database Services
Note:
You can also configure static service information with Oracle Net Manager.
See Statically Configure Database Service Information in the online help for additional information.
See Also:
"
Configuring Dynamic Service Registration
(page 9-2)" for additional information about configuring dynamic service registration Oracle Databases
13.6 Configuring Connections to Third-Party Database Services
The following topics describe how to configure connections to third-party database services:
•
Default Configuration for External Procedures
(page 13-24)
•
About Oracle Net Services for Oracle Heterogeneous Services (page 13-29)
•
Configuring Oracle Net Services for an Oracle Rdb Database (page 13-31)
13.6.1 Default Configuration for External Procedures
is a procedure called from another program, written in a different language. An example would be a PL/SQL program calling one or more C routines that are required to perform special-purpose processing.
When an application calls an external procedure, Oracle Database starts an external procedure agent named extproc. Using the network connection established by Oracle
Database, the application passes the following information to the agent:
• DLL or shared library name
• External procedure name
• Any parameters
The agent then loads the DLL or the shared library, and runs the external procedure and passes back to the application any values returned by the external procedure. The agent must reside on the same computer as the application making the external procedure call.
When you use the default configuration for external procedures, the extproc
agent is spawned directly by Oracle Database. There are no configuration changes required for either the listener.ora
or tnsnames.ora
file. However, you must define the environment variables to be used by external procedures in the extproc.ora
file located in the
ORACLE_HOME/hs/admin
directory. If the default configuration for
external procedures is not used, then the parameters listed in Table 13-7
(page 13-25) must be set.
13-24 Oracle Database Net Services Administrator's Guide
Configuring Connections to Third-Party Database Services
Table 13-7 External Procedures Settings in listener.ora
Oracle Enterprise
Manager Cloud
Control Field
Program Name
listener.ora
Parameter
PROGRAM
Description
Environment Variables ENVS
The name of the external procedure agent executable.
Note:
On Microsoft Windows, the executable must reside in the
ORACLE_HOME\bin
directory.
The environment variables to be used by external procedures in the extproc.ora
file located in the
ORACLE_HOME/hs/admin directory.
Note:
When extproc.ora
is in use, it precedes the same environment variables of
ENVS
in listener.ora
.
Syntax:
SET name=value
Example:
SET EXTPROC_DLLS=ANY
Specify the EXTPROC_DLLS environment variable to restrict the
DLLs that the extproc agent is allowed to load. Without the
EXTPROC_DLLS environment variable, the extproc agent loads DLLs from the
ORACLE_HOME/lib
directory on UNIX operating systems and the
ORACLE_HOME\bin
directory on Microsoft Windows.
Set EXTPROC_DLLS to one of the following values:
• Colon-separated list of DLLs
Syntax:
"DLL:DLL"
This value allows the extproc agent to load the specified DLLs and the DLLs from the
ORACLE_HOME/lib
directory on UNIX operating systems and the
ORACLE_HOME\bin
directory on
Microsoft Windows. You must enter the complete directory path and file name of the DLLs.
•
ONLY
(Recommended for maximum security)
Syntax:
"ONLY:DLL:DLL"
This value allows the extproc agent to load only the specified
DLLs. You must enter the complete directory path and file name of the DLLs.
•
ANY
Syntax:
"ANY"
Description:
This value allows the extproc agent to load any
DLL.
ANY
disables DLL checking.
Examples:
"EXTPROC_DLLS=/home/xyz/mylib.so:/home/abc/urlib.so,
LD_LIBRARY_PATH=/private/xpm/lib:/private/mylibs,
MYPATH=/usr/ucb:/usr/local/packages,APL_ENV_FILE=/apl/conf/env.txt"
"EXTPROC_DLLS=ONLY:/home/xyz/mylib.so:/home/abc/urlib.so,
LD_LIBRARY_PATH=/private/xpm/lib:/private/mylibs,
MYPATH=/usr/ucb:/usr/local/packages,APL_ENV_FILE=/apl/conf/env.txt"
"EXTPROC_DLLS=ANY,LD_LIBRARY_PATH=/private/xpm/lib:/private/mylibs,
MYPATH=/usr/ucb:/usr/local/packages,APL_ENV_FILE=/apl/conf/env.txt"
Oracle Home Directory ORACLE_HO
ME
Oracle System
Identifier (SID)
SID_NAME
The Oracle home location of the agent.
A system identifier for the external procedure agent by any name.
Enabling Advanced Features of Oracle Net Services 13-25
Configuring Connections to Third-Party Database Services
1
The DLLs are separated by semi-colons (;) on Microsoft Windows.
Note:
The default configuration for external procedures does not require a network listener to work with Oracle Database and the extproc
agent. The extproc agent is spawned directly by Oracle Database and eliminates the risks that the extproc
agent might be spawned by Oracle Listener unexpectedly. This default configuration is recommended for maximum security.
You can change the default configuration for external procedures and have the extproc
agent spawned by Oracle Listener. To do this, you must perform additional network configuration steps.
Having the extproc
agent spawned by Oracle Listener is necessary if you use:
• Multi-threaded agent
• Oracle Database in MTS mode on Microsoft Windows
• The AGENT clause of the LIBRARY specification or the AGENT IN clause of the PROCEDURE specification such that you can redirect external procedures to a different extproc
agent.
See Also:
Oracle Database Security Guide
for additional information about securing external procedures
13.6.1.1 Configuring Oracle Net Services for External Procedures
You can change the default configuration for external procedures and have the extproc agent spawned by the listener similar to earlier releases of Oracle Database.
(page 13-26) shows a sample configuration in the listener.ora
file.
Example 13-2 listener.ora File with an External Procedure
LISTENER=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sale-server)(PORT=1521))
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))))
(page 13-26) shows a sample configuration in the tnsnames.ora
file.
Example 13-3 tnsnames.ora File with an External Procedure
EXTPROC_CONNECTION_DATA=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=ipc)
(KEY=extproc)
)
(CONNECT_DATA=
(SID=plsextproc)
))
The listener for external procedures should have a user account that does not have general access to the files owned by the oracle
user. Specifically, this user should not have permission to read or write to database files or to the Oracle server address
13-26 Oracle Database Net Services Administrator's Guide
Configuring Connections to Third-Party Database Services space. In addition, this user should have read access to the listener.ora
file, but must not have write access to it.
Running the listener with lower privileges also prevents using the Listener Control
SET
commands to alter the configuration of the listener in the listener.ora
file. For this reason, Oracle recommends that you complete listener.ora
file configuration before running the listener.
13.6.1.1.1 Modifying the Default Configuration for External Procedures
To modify the default configuration for external procedures, configure and run a separate or existing listener to serve external procedures. The following procedure describes how to modify the default configuration:
1.
Configure an existing listener to serve external procedures using Oracle Net
Configuration Assistant as follows. For most installation types, this listener is named
LISTENER
.
a.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
b.
c.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Click Go.
The Listeners page appears.
2.
d.
e.
f.
g.
Select the existing listener created by Oracle Net Configuration Assistant, and then click Edit.
The Edit Listeners page appears.
In the Addresses section, select the protocol address for external procedures, and then click Add.
Click the Other Services tab.
Select the row representing the service information for external procedures, and then click Add.
Add service information about the extproc agent in the listener.ora
file,
including the parameters described in Table 13-7
(page 13-25).
13.6.1.1.2 Creating a New Listener to Run External Procedures
To configure and run a separate listener to serve external procedures, create the external procedure entries for a different listener using Oracle Net Configuration
Assistant. The following procedure describes how to create a new listener:
1.
Create a listener to exclusively handle external procedures, as follows:
2.
a.
b.
c.
Navigate to the Listeners page.
Click Create.
The Create Listener page appears.
In the Listener Name field, enter a unique listener name, such as
LISTENEREXTPROC
, in the Listener Name field.
In the Addresses section, configure an IPC protocol address, as follows:
Enabling Advanced Features of Oracle Net Services 13-27
Configuring Connections to Third-Party Database Services
a.
b.
c.
d.
Click Add.
The Add Address page appears.
From the Protocol list, select IPC.
In the Key field, enter a key value of the extproc agent.
Click OK.
See Also:
"
Configuring Listening Protocol Addresses
(page 9-10)" for additional information about configuring listener protocol addresses
3.
4.
Add service information about the extproc agent in the listener.ora
file,
including the parameters described in Table 13-7
(page 13-25), as follows:
a.
Click the Other Services tab.
b.
c.
Click Add.
The Create Other Service page appears.
Enter the following values in the fields:
d.
e.
f.
g.
• extproc
in the Program Name field.
• The Oracle home where the extproc
executable resides in the Oracle
Home Directory field.
• System identifier, such as extproc
, in the SID field.
In the Environment Variables section, click Add Another Row.
Enter the EXTPROC_DLLS environment variable in the Name field, and the directory path and file name of the DLLs in the Value field.
Click OK.
The Create Listener page appears.
Click OK to add the listener.
The listener is added to the Listeners page.
The listener.ora
file updates with information for external procedures, as shown in the following output:
LISTENEREXTPROC=
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=ipc)(KEY=extproc)))
Start the listener for external procedures from a user account with lower privileges than the oracle
user.
13-28 Oracle Database Net Services Administrator's Guide
Configuring Connections to Third-Party Database Services
See Also:
•
" Starting Oracle Net Listener and the Oracle Database Server (page 6-2)"
for instructions on using the Listener Control utility
START
command to start the listener
•
Oracle Database Development Guide
for instruction on enabling external procedure calls
13.6.2 About Oracle Net Services for Oracle Heterogeneous Services
Heterogeneous Services is an integrated component within the Oracle database server, and provides the generic technology for accessing third-party systems from the Oracle database server. Heterogeneous Services enables you to:
• Use Oracle SQL to transparently access data stored in third-party systems as if the data resides within an Oracle database server.
• Use Oracle procedure calls to transparently access third-party systems, services, or application programming interfaces (APIs) from your Oracle distributed environment.
While Heterogeneous Services provides the generic technology in the Oracle database server, a Heterogeneous Services agent is required to access a particular third-party system.
13.6.2.1 Configuring Oracle Database to Connect to Agents
To initiate a connection to the third-party system, the Oracle database server starts an agent process through the listener on the gateway. The following procedure describes how to configure the Oracle database server to be able to connect to the agents:
1.
Configure the listener on the gateway to listen for incoming requests from the
Oracle database server and spawn Heterogeneous Services agents by configuring the following parameters in the listener.ora
file:
2.
• PROGRAM: The name of the agent executable
• ORACLE_HOME: The Oracle home location of the agent executable
• SID_NAME: The Oracle system identifier (SID)
Configure the PROGRAM, ORACLE_HOME, and SID parameters in Oracle
Enterprise Manager Cloud Control.
a.
Access the Net Services Administration page in Oracle Enterprise Manager
Cloud Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
b.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Enabling Advanced Features of Oracle Net Services 13-29
Configuring Connections to Third-Party Database Services
3.
c.
d.
e.
f.
g.
h.
i.
Click Go.
The Listeners page appears.
Select the listener created by Oracle Net Configuration Assistant, and then click Edit.
The Edit Listeners page appears.
Click the Other Services tab.
Click Add.
The Create Other Service page appears.
Enter the program name in the Program Name field that will be run to create a gateway, the Oracle home where the agent executable resides in the Oracle
Home Directory field, and the Oracle System Identifier (SID) or service name of the third-party system in the SID field.
Click OK.
The Edit Listener page appears.
Click OK to modify the listener.
The Listeners page appears.
The listener.ora
file updates information about the Heterogeneous
Services, as shown in the following:
SID_LIST_LISTENER=
(SID_LIST=
(SID_DESC=
(SID_NAME=sybasegw)
(ORACLE_HOME=/oracle12c)
(PROGRAM=tg4sybs)))
On the computer where the Oracle database resides, set up a network service name to connect to the listener on the gateway. The connect descriptor must include the
HS=ok
clause to ensure the connection uses Heterogeneous Services, as follows:
a.
Create a network service name that can be used for connections from the
Oracle database server to a third-party system.
See Also:
Task 1, Configure Net Services Names
(page 8-8) for local naming instructions
and Task 2, Create Net Service Names in the Directory
(page 8-15) for directory naming instructions
b.
Use either Oracle Enterprise Manager Cloud Control or Oracle Net Manager to configure
HS=ok
.
• For Oracle Enterprise Manager Cloud Control, access the Net Services
Administration
page, select Local Naming for the listener, and then click the Advanced tab in the Create Net Service Name page. Next, click Use
for Heterogeneous Services
.
13-30 Oracle Database Net Services Administrator's Guide
Configuring Connections to Third-Party Database Services
c.
• For Oracle Net Manager, click Advanced in the Service Identification box.
The Advanced Service Options dialog box appears. Click Use for
Heterogeneous Services
.
Click OK to confirm the change.
The tnsnames.ora
file updates with the new network service name configured for Heterogeneous Services, as shown in the following: sybase_gtw=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=gate-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sybasegw)
)
(HS=ok)))
)
See Also:
Oracle Database Heterogeneous Connectivity Administrator's Guide
13.6.3 Configuring Oracle Net Services for an Oracle Rdb Database
Oracle Rdb is a database for Digital 64-bit operating systems. Because Oracle Rdb has its own listener, the client interacts with Rdb in the same manner as it does with an
Oracle database.
To initiate a connection to an Oracle Rdb, set up a network service name to connect to the Oracle Rdb database using the parameters described in
(page 13-31).
Table 13-8 Oracle RDB Database Settings in a Connect Descriptor
tnsnames.ora Parameter Description Oracle Enterprise
Manager Cloud
Control Field
Rdb Database
Type of Service
RDB_DATABASE
TYPE_OF_SERVICE
Global Database Name GLOBAL_NAME
The file name of an Oracle Rdb database.
The type of service to use for an Oracle Rdb database. It is used by Rdb interface tools. This feature should only be used if the application supports both Oracle Rdb and
Oracle database services, and you want the application to load balance between the two.
The Oracle Rdb database. Optional.
The following procedure describes how to configure a client for an Oracle Rdb database:
1.
Create a network service name that can be used for connections from the Oracle server to a third-party system.
Enabling Advanced Features of Oracle Net Services 13-31
Configuring Connections to Third-Party Database Services
See Also:
Task 1, Configure Net Services Names
(page 8-8) for local naming instructions
and Task 2, Create Net Service Names in the Directory
(page 8-15) for directory naming instructions
2.
3.
4.
Use either Oracle Enterprise Manager Cloud Control or Oracle Net Manager to set the Oracle Rdb parameters.
• For Oracle Enterprise Manager Cloud Control, access the Net Services
Administration
page, select Local Naming for the listener, and then click the
Advanced
tab in the Create Net Service Name page.
• For Oracle Net Manager, click Advanced in the Service Identification section.
The Advanced Service Options dialog box appears.
Enter the file name of an Oracle Rdb database in the Rdb Database field.
(Optional) Specify the type of service in the Type of Service field, if needed, and enter the global database name in the Global Database Name field, and then click
OK.
The tnsnames.ora
file updates with the new network service name configured for the Oracle Rdb database, similar to the following: alpha5=
(DESCRIPTION=
(ADDRESS=...)
(CONNECT_DATA=
(SERVICE_NAME=generic)
(RDB_DATABASE=[.mf]mf_personnel.rdb)
(GLOBAL_NAME=alpha5)))
In the following example, the TYPE_OF_SERVICE parameter is used to load balance between an Oracle Rdb database service and an Oracle database service: alpha5=
(DESCRIPTION_LIST=
(DESCRIPTION=
(ADDRESS=...)
(CONNECT_DATA=
(SERVICE_NAME=generic)
(RDB_DATABASE=[.mf]mf_personnel.rdb)
(GLOBAL_NAME=alpha5)))
(DESCRIPTION=
(ADDRESS=...)
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com))
(TYPE_OF_SERVICE=oracle_database))
13-32 Oracle Database Net Services Administrator's Guide
14
Optimizing Performance
Learn how to optimize connection performance.
•
Understanding the Benefits of Network Data Compression
(page 14-1)
•
Configuring Session Data Unit (page 14-1)
•
Determining the Bandwidth-Delay Product (page 14-3)
•
(page 14-4)
•
Configuring SDP Support for InfiniBand Connections
(page 14-6)
•
Configuring Exadirect Support for InfiniBand Connections
(page 14-8)
•
Limiting Resource Consumption by Unauthorized Users
(page 14-10)
•
About Session-Based Routing (page 14-11)
14.1 Understanding the Benefits of Network Data Compression
Network data compression reduces the size of the
transmitted over a data connection. Reducing the size of data reduces the time required to transmit a SQL query and result across the network. In addition, compressed data uses less bandwidth which allows transmission of larger data in less time. The data compression process is transparent to the application layer.
The following are some of the benefits of using data compression:
• Increased network throughput means constrained bandwidth environments can utilize compression to reduce query response time.
• Reduced bandwidth utilization allows other applications to use the bandwidth.
• Reduction in the amount of data transferred between sites.
14.2 Configuring Session Data Unit
Under typical database configuration, Oracle Net encapsulates data into buffers the size of the SDU before sending the data across the network. Oracle Net sends each buffer when it is filled, flushed, or when an application tries to read data. Adjusting the size of the SDU buffers relative to the amount of data provided to Oracle Net to send at any one time can improve performance, network utilization, and memory consumption. When large amounts of data are being transmitted, increasing the SDU size can improve performance and network throughput. SDU size can be adjusted lower or higher to achieve higher throughput for a specific deployment.
The amount of data provided to Oracle Net to send at any one time is referred to as the message size.
Optimizing Performance 14-1
Configuring Session Data Unit
The SDU size can range from 512 bytes to 2 MB. The wide range of sizes allows the network administrator to tune the SDU size for optimal network performance for a given deployment. A high SDU size value requires more memory. The default SDU size for the client and a dedicated server is 8192 bytes. The default SDU size for a shared server is 65535 bytes.
The actual SDU size used is negotiated between the client and the server at connect time and is the smaller of the client and server values. Configuring an SDU size different from the default requires configuring the SDU on both the client and server computers, unless you are using shared servers.
You should consider changing the SDU size when the predominant message size is smaller or larger than 8192. The SDU size should be 70 bytes more than the predominant message size. If the predominant message size plus 70 bytes exceeds the maximum SDU, then the SDU should be set such that the message size is divided into the smallest number of equal parts where each part is 70 bytes less than the SDU size.
To change the default, change the DEFAULT_SDU_SIZE parameter in the sqlnet.ora
file.
For example, if the majority of the messages sent and received by the application are smaller than 8 KB, taking into account the 70 bytes for overhead, then setting the SDU to 8 KB will likely produce good results. If sufficient memory is available, then using the maximum value for the SDU minimizes the number of system calls and overhead for Oracle Net Services.
Note:
In Oracle Database 11g, Oracle Net Services optimized bulk data transfer for components, such as Oracle SecureFiles LOBs and Oracle Data Guard redo transport services. The SDU size limit, as specified in the network parameter files, does not apply to these bulk data transfers.
See Also:
•
" Session Data Unit Size for Data Transfer Optimization
(page 1-10)"
•
" Statistics Example (page 16-63)"
14.2.1 Setting the SDU Size for the Database
To set the SDU size for the database server, configure the following files:
• sqlnet.ora
Configure the DEFAULT_SDU_SIZE parameter in the sqlnet.ora
file, such as the following:
DEFAULT_SDU_SIZE=32767
• Initialization parameter file
If using shared server processes, then set the SDU size in the DISPATCHERS parameter in the initialization parameter file, as follows:
DISPATCHERS="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp))(SDU=8192))"
14-2 Oracle Database Net Services Administrator's Guide
Determining the Bandwidth-Delay Product
• listener.ora
If the listener was configured with a list of targets in the listener.ora
file, then the value for SDU in the SID_LIST parameter overrides the current setting in the sqlnet.ora
file when using dedicated server processes.
14.2.2 Setting the SDU Size for the Client
To set the SDU size for the client, configure the following files:
• sqlnet.ora
For global configuration on the client side, configure the DEFAULT_SDU_SIZE parameter in the sqlnet.ora
file, such as the following:
DEFAULT_SDU_SIZE=32767
• tnsnames.ora
For a particular connect descriptor, you can specify the SDU parameter in the
DESCRIPTION parameter.
sales.us.example.com=
(DESCRIPTION=
(
SDU=11280)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com))
)
The SDU size applies to all Oracle Net protocols for the particular connect descriptor.
14.3 Determining the Bandwidth-Delay Product
Bandwidth-delay product is the product of network bandwidth and the round trip time of data going over the network. A simple way to determine the round trip time, is to use a command such as ping
from one host to another and use the response times returned by ping
.
For example, if a network has a bandwidth of 100 Mbps and a round trip time of 5ms, then the send and receive buffers should be at least (100*10ˆ6) * (5/10ˆ3) bits or approximately 62.5 Kilobytes.
The following equation shows the relationships between the units and factors involved:
100,000,000 bits 1 byte 5 seconds
---------------- x ------ x --------- = 62,500 bytes
1 second 8 bits 1000
Setting the SEND_BUF_SIZE and RECV_BUF_SIZE parameters to at least the bandwidth-delay product insures that when large amounts of data are being sent that the network bandwidth will be optimally utilized.
Based on the preceding equation, the bandwidth-delay product of this network link is approximately 64 KB. If the largest message used to transfer redo data between a primary database and a standby database is 1 MB, then the value for the
SEND_BUF_SIZE and RECV_BUF_SIZE parameters could be 1 MB. However, if the average message is less, then a setting of 64 KB should be sufficient to optimize use of the available bandwidth.
Optimizing Performance 14-3
Configuring I/O Buffer Space
For most network protocols, ensure that the RECV_BUF_SIZE parameter at one end of the network connection, typically at the client, equals the value of the
SEND_BUF_SIZE parameter at the other end, typically at the server.
See Also:
"
Statistics Example (page 16-63)" for additional information about
determining messages sizes
14.4 Configuring I/O Buffer Space
Reliable network protocols, such as TCP/IP, buffer data into send and receive buffers while sending and receiving to or from lower and upper layer protocols. The sizes of these buffers affect network performance by influencing flow control decisions.
The RECV_BUF_SIZE and SEND_BUF_SIZE parameters specify sizes of socket buffers associated with an Oracle Net connection. To ensure the continuous flow of data and better utilization of network bandwidth, specify the I/O buffer space limit for receive and send operations of sessions with the RECV_BUF_SIZE and SEND_BUF_SIZE parameters. The RECV_BUF_SIZE and SEND_BUF_SIZE parameter values do not have to match, but should be set according to your environment.
For best performance, the size of the send and receive buffers should be set large enough to hold all the data that may be sent concurrently on the network connection.
For optimal network performance, these buffers should be set to at least the bandwidth-delay product.
Use these parameters with caution as they affect network and system performance.
The default values for these parameters are operating system specific. The following are the defaults for the Linux operating system:
• SEND_BUF_SIZE: 131,072 bytes (128k)
• RECV_BUF_SIZE: 174,700 bytes
These parameters are supported for TCP, TCP/IP with SSL, and SDPs. Additional protocols may support these parameters on certain operating systems. The recommended values for these parameters are specified in the installation guide. Refer to operating system specific documentation for additional information.
Note:
• The actual value of the SEND_BUF_SIZE and RECV_BUF_SIZE parameters may be less than the value specified because of limitations in the host operating system or due to memory constraints.
• It is important to consider the total number of concurrent connections that your system must support and the available memory resources. The total amount of memory consumed by these connections depends on the number of concurrent connections and the size of their respective buffers.
14-4 Oracle Database Net Services Administrator's Guide
Configuring I/O Buffer Space
See Also:
Oracle Call Interface Programmer's Guide
for additional information about the
OCI_PREFETCH_MEMORY parameter
14.4.1 Configuring I/O Buffer Size on the Server
Because the database server writes data to clients, setting the SEND_BUF_SIZE parameter on the server-side is typically adequate. If the database server is receiving large requests, then also set the RECV_BUF_SIZE parameter.To configure the database server, set the buffer space size in the listener.ora
and sqlnet.ora
files.
In the listener.ora
file, specify the buffer space parameters for a particular protocol address or for a description. The following is an example of the settings:
LISTENER=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)
(SEND_BUF_SIZE=11784)
(RECV_BUF_SIZE=11784)
)
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc)
(SEND_BUF_SIZE=11784)
(RECV_BUF_SIZE=11784)))
LISTENER2=
(DESCRIPTION=
(SEND_BUF_SIZE=8192)
(RECV_BUF_SIZE=16384)
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)))
Although the preceding example has multiple addresses, the
ADDRESS_LIST parameter was not used. This is because the
ADDRESS_LIST
parameter is not mandatory.
The following is an example of the settings in the sqlnet.ora
file:
RECV_BUF_SIZE=65536
SEND_BUF_SIZE=65536
14.4.1.1 Setting the Buffer Size Parameter for Shared Server Processes
If using shared server processes, then you can override the current settings obtained from the server sqlnet.ora
file by setting the buffer space parameters in the
DISPATCHERS initialization parameter as follows:
DISPATCHERS="(ADDRESS=(PROTOCOL=tcp)(SEND_BUF_SIZE=65536))"
14.4.2 Configuring I/O Buffer Space on the Client
To configure the client, set the buffer space size in the following locations in the specified file:
• Setting only the RECV_BUF_SIZE parameter is typically adequate. If the client is sending large requests, then also set the SEND_BUF_SIZE parameter. These parameters are set in the client's sqlnet.ora
file.
• For a particular connect descriptor, you can override the current settings in the client sqlnet.ora
file. You can specify the buffer space parameters for a
Optimizing Performance 14-5
Configuring SDP Support for InfiniBand Connections particular protocol address or description in the tnsnames.ora
file similar to the following: sales.us.example.com=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)
(SEND_BUF_SIZE=11784)
(RECV_BUF_SIZE=11784))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)
(SEND_BUF_SIZE=11784)
(RECV_BUF_SIZE=11784))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com))) hr.us.example.com=
(DESCRIPTION=
(SEND_BUF_SIZE=8192)
(RECV_BUF_SIZE=8192)
(ADDRESS=(PROTOCOL=tcp)(HOST=hr1-server)(PORT=1521))
(CONNECT_DATA=
(SERVICE_NAME=hr.us.example.com)))
14.5 Configuring SDP Support for InfiniBand Connections
Oracle Net Services provides support for the Sockets Direct Protocol (
InfiniBand high-speed networks.
SDP is a standard communication protocol for clustered server environments. SDP is an interface between a network interface card and the application. By using SDP, applications place most of the messaging burden upon the network interface card,
freeing the CPU for other tasks. As a result, SDP decreases network
and CPU utilization.
SDP is designed specifically for System Area Networks (SANs). A SAN is characterized by short-distance, high-performance communications between multiple server systems, such as Oracle WebLogic Server or any other third-party middle-tier client and database servers clustered on one switch.
Note:
Check with your individual vendor for their version compatibility with Oracle
Database 12c.
Visit the Oracle Technology Network for additional information about SDP support at http://www.oracle.com/technetwork/index.html
The following sections describe how to set up Oracle Net support of SDP for middle tier and database server communication. It contains the following topics:
•
Prerequisites for Using SDP (page 14-7)
•
(page 14-7)
•
(page 14-8)
14-6 Oracle Database Net Services Administrator's Guide
Configuring SDP Support for InfiniBand Connections
See Also:
"
(page 1-9)" for an overview of supported deployments
14.5.1 Prerequisites for Using SDP
Prior to configuring support for SDP, install the required hardware, and set up
InfiniBand hardware and software compatible with OpenFabrics Enterprise
Distribution (OFED) 1.4 or 1.5 from a designated vendor on both the application web server and database server.
During installation of the InfiniBand software, identify the constant that defines SDP or the address family for the system. This can be obtained from the operating system or OFED documentation.
See Also:
Vendor documentation for installation information
14.5.2 Configuring SDP on the Server
To configure the database server, configure an SDP address in the listener.ora
file on the database server.
Note:
If the SDP or address protocol family constant is not 27, the default value for
Oracle Net Services, then define the constant in the SDP.PF_INET_SDP
parameter in the sqlnet.ora
file.
The following example shows an SDP endpoint that uses port number 1521 on the computer sales-server
.
LISTENER=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=sdp)(HOST=sales-server)(PORT=1521))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))))
See Also:
"
Creating a List of Listener Protocol Addresses (page 13-1)"
Optimizing Performance 14-7
Configuring Exadirect Support for InfiniBand Connections
14.5.3 Configuring SDP on the Client
Note:
If the SDP or address protocol family constant is not 27, the default value for
Oracle Net Services, then define the constant in the SDP.PF_INET_SDP
parameter in the sqlnet.ora
file.
The following procedure describes how to configure the Oracle WebLogic Server servers or third-party middle-tier client:
1.
If configuring third-party middle-tier client, then upgrade the clients to use Oracle
Database 12c client software, as follows:
a.
Run Oracle Universal Installer.
2.
b.
Select Oracle Database 12c Client from the Available Products page.
For both Oracle WebLogic Server servers and third-party middle-tier client, create a network service name to connect to the database server, as follows:
• For Oracle WebLogic Server servers, specify a network service name that uses the same TCP/IP protocol address configured in the tnsnames.ora
file. For example: sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
• For third-party middle-tier clients, specify a network service name that uses the same SDP address configured in the tnsnames.ora
file.
For example: sales=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=sdp)(HOST=sales-server)))
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
See Also:
Configuring Naming Methods (page 8-1) for additional information about
creating connect descriptors
14.6 Configuring Exadirect Support for InfiniBand Connections
Oracle Net Services provides support for the Exadirect for InfiniBand high-speed networks.. Use the new transport to improve latency and throughput by leveraging
Remote Direct Memory Access (RDMA) in an InfiniBand environment
Exadirect protocol uses TCP for control communication and IB RC transport for data.
The Exadirect protocol adapter is supported only on Oracle Solaris and Oracle Linux in this release.
14-8 Oracle Database Net Services Administrator's Guide
Configuring Exadirect Support for InfiniBand Connections
The following sections describe how to set up Oracle Net support of Exadirect for middle tier and database server communication. It contains the following topics:
•
Prerequisites for Using Exadirect (page 14-9)
•
Configuring Exadirect on the Server
(page 14-9)
•
Configuring Exadirect on the Client
(page 14-9)
Note:
In Oracle Database 12c release 2 (12.2), Exadirect supports a single
Exadirect endpoint configuration. It does not support DRCP.
14.6.1 Prerequisites for Using Exadirect
Exadirect can be used as a transport protocol between Exadata nodes. The Exadata version must be 12.1.2.3.3 or higher for Exadirect to work.
14.6.2 Configuring Exadirect on the Server
To configure the database server, configure an Exadirect address in the listener.ora
file on the database server.
Configure enable_exadirect_listener_name=on
parameter in listener.ora
file.
The following example shows an Exadirect endpoint that uses port number
1522
on the computer having IB interface as
192.168.10.1
.
LISTENER
=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=exadirect)(HOST=192.168.10.1)(PORT=1522))
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))))
ENABLE_EXADIRECT_LISTENER=on
Note:
To enable Exadirect flow control, set exadirect_flow_control=on in sqlnet.ora
file. This is a negotiated parameter and should be set in both the server and the client sqlnet.ora
file.
14.6.3 Configuring Exadirect on the Client
Specify a network service name that uses the same Exadirect address that is configured in the tnsnames.ora
file.
Enable Exadirect flow control by setting exadirect_flow_control=on
in sqlnet.ora
file.
For example:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=exadirect)(HOST=192.168.10.1)(port=1522))
Optimizing Performance 14-9
Limiting Resource Consumption by Unauthorized Users
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
14.7 Limiting Resource Consumption by Unauthorized Users
Unauthorized access to the listener or database server can result in denial-of-service attacks, whereby an unauthorized client attempts to block authorized users' ability to access and use the system when needed. Malicious clients may attempt to flood the listener or database server with connect requests that have the sole purpose of consuming resources, such as connections, processes, or threads. To mitigate these types of attacks, configure limits that constrain the time in which resources can be held prior to authentication. Client attempts to exceed the configured limits result in connection terminations and an audit trail containing the IP address of the client being logged.
To limit the resource consumption by unauthorized users and enable the audit trail,
set time-limit values for the parameters described in Table 14-1
(page 14-10). These parameters do not have default values.
Table 14-1 Connect-Timeout Parameters
Parameter
INBOUND_CONNECT_TI
MEOUT_listener_name
File Description
listener.ora
The time, in seconds, for the client to complete its connect request to the listener after the network connection had been established.
If the listener does not receive the client request in the time specified, then it terminates the connection. In addition, the listener logs the IP address of the client and an
Listener Has Not Received Client's Request in Time Allowed
(page 16-17) error message to the listener.log
file.
SQLNET.INBOUND_CON
NECT_TIMEOUT sqlnet.ora
on the database server
The time, in seconds, for a client to connect with the database server and provide the necessary authentication information.
If the client fails to establish a connection and complete authentication in the time specified, then the database server terminates the connection. In addition, the database server logs
the IP address of the client and an ORA-12170: Connect Timeout
Occurred (page 16-14) error message to the
sqlnet.log
file.
The client receives either an ORA-12547: TNS:lost contact, or an
ORA-12637: Packet receive failed error message.
When specifying values for these parameters, consider the following recommendations:
• Set both parameters to an initial low value.
• Set the value of the INBOUND_CONNECT_TIMEOUT_listener_name parameter to a lower value than the SQLNET.INBOUND_CONNECT_TIMEOUT parameter.
For example, you can set INBOUND_CONNECT_TIMEOUT_listener_name to 2 seconds and INBOUND_CONNECT_TIMEOUT parameter to 3 seconds. If clients are unable to complete connections within the specified time due to system or network delays that are normal for the particular environment, then increment the time as needed.
14-10 Oracle Database Net Services Administrator's Guide
About Data-Dependent Routing
See Also:
•
" Resolving the Most Common Error Messages for Oracle Net Services
(page 16-11)" for a description of error message workarounds
•
" Analyzing Listener Log Files
(page 16-29)" for additional information about entries in the listener.log
file
•
" About Advanced Profile Information
(page 12-6)" for additional information about configuring these parameters
14.8 About Data-Dependent Routing
Sharding provides the ability to horizontally partition the data across multiple independent Oracle databases, also called shards, and based on a key specified in the connect string, route the database requests to a particular shard.
The routing is done at the session level and is based on the value of the sharding key specified in the connection string. The data-dependent routing assumes that all the database requests issued within a session are related to the data associated with the specified key value. If a client needs to access data with a different value of the key, it either establishes a new database session or re-uses a pre-established connection that maps to that sharding key. All the components that are responsible for routing database requests, such as shard directors (Global Service Managers) and connection pools, contain a routing table which maps the key value range to shards that store appropriate data. Oracle Sharding automatically maintains consistency of routing tables across all these components.
14.8.1 Configuring Data-Dependent Routing for Client-Server Connections
It involves a single redirection of the connection request process.
Composite sharding enables two levels of sharding - one by list or range and another by consistent hash. This is accomplished by the application providing two keys: a super sharding key and a sharding key. With data-dependent routing, the connect string used by the clients to connect to a shard must contain either the
(SHARDING_KEY=…)
or
(SHARDING_KEY=…) (SUPER_SHARDING_KEY=...)
in the
CONNECT_DATA
section. The connect string should be in the format required to connect to a global service. The shard directors should be specified as endpoints and, a global service name and region name should be used in
CONNECT_DATA
in addition to the
SUPER_SHARDING_KEY
, or the
SHARDING_KEY
, or both.
To process a connection request:
• A connection is established to one of the shard directors.
• The shared director performs a lookup for the service and key values, and then redirects the client to a shard containing the data.
The client executes a SQL statement and receives results directly from the shard.
Here is an example of the connect string for a shard:
(DESCRIPTION=
(FAILOVER=on)
(ADDRESS_LIST=
Optimizing Performance 14-11
About Data-Dependent Routing
(LOAD_BALANCE=ON)
(ADDRESS=(host=sales-east1)(port=1522))
(ADDRESS=(host=sales-east2)(port=1522))
(ADDRESS=(host=sales-east3)(port=1522)))
(ADDRESS_LIST=
(LOAD_BALANCE=ON)
(ADDRESS=(host=sales-west1)(port=1522))
(ADDRESS=(host=sales-west2)(port=1522))
(ADDRESS=(host=sales-west3)(port=1522)))
(CONNECT_DATA=
(SERVICE_NAME=sales)
(SHARDING_KEY=40598230) (SUPER_SHARDING_KEY=gold)
(REGION=east)))
Related Topics:
Oracle Database Global Data Services Concepts and Administration Guide
14-12 Oracle Database Net Services Administrator's Guide
Part III
Testing and Troubleshooting Oracle Net
Services
Part III describes how to establish connections, and identify and diagnose problems with Oracle Net Services.
This part contains the following chapters:
•
(page 15-1)
•
Troubleshooting Oracle Net Services
(page 16-1)
15
Testing Connections
After you have configured the network, you should connect and test each component to ensure that the network is functioning properly. Oracle Net Services provides tools to help you test the listener, database, and Oracle Connection Manager.
•
Testing the Network (page 15-1)
•
Using the TNSPING Utility to Test Connectivity from the Client (page 15-2)
•
Using the TRCROUTE Utility to Test Connectivity from the Client
(page 15-4)
15.1 Testing the Network
The following is the recommended sequence for testing the network:
1.
2.
3.
Start and test each listener. To start the listener, use the procedure described in
" Starting Oracle Net Listener and the Oracle Database Server (page 6-2)".
To test a listener, initiate a connection from a client to any active database controlled by that listener.
Start and test each Oracle Connection Manager, if included in your network. To start Oracle Connection Manager, use the procedure described in "
(page 6-4)".
To test Oracle Connection Manager, initiate a connection from a client to any active database that has been registered with Oracle Connection Manager.
Test the server with a loopback test or Oracle Net Manager.
uses Oracle Net to go from the database server back to itself,
bypassing the Interprocess Communication (IPC). Performing a successful loopback verifies that Oracle Net is functioning on the database server. The following procedure describes how to perform a loopback test using Oracle Net
Manager:
a.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
b.
c.
d.
In the navigator, expand Directory or Local, and then select Service Naming.
Select the network service name or database service.
Choose Command, and then select Test Net Service.
Testing Connections 15-1
Using the TNSPING Utility to Test Connectivity from the Client
Testing assumes the listener and database are running. If they are not, then see "
Starting Oracle Net Listener and the Oracle Database Server
(page 6-2)" to start components.
During testing, a Connection Test dialog box appears, providing status and test results. A successful test results in the following message:
The connection test was successful.
If the test was successful, then proceed to step 3.e
If the test was not successful, then use the error message to determine further action. For example, if the error message is the following:
Attempting to connect using userid: scott
The test did not succeed.
ORA-28000: the account is locked
There may be an error in the fields entered, or the server may not be ready for a connection.
4.
e.
Change the user name to an account known to be unlocked. To change the user name, click Change Login. You are prompted for the password.
Click Close to close the Connect Test dialog box.
Test client with a connection.
To test several different clients in your network, initiate a connection to a database server from each of them using the following command:
CONNECT
username
@
connect_identifier
15.2 Using the TNSPING Utility to Test Connectivity from the Client
The TNSPING utility determines whether the listener for a service on an Oracle Net network can be reached successfully.
If you can connect successfully from a client to a server (or a server to another server) using the TNSPING utility, then it displays an estimate of the round trip time (in milliseconds) it takes to reach the Oracle Net service.
If it fails, then it displays a message describing the error that occurred. This enables you to see the network error that is occurring without the overhead of a database connection.
Use the following command to test connectivity: tnsping
net_service_name
count
In the preceding command, the following arguments are used:
•
net_service_name
must exist in tnsnames.ora
file or the name service in use, such as NIS.
•
count
determines how many times the program attempts to reach the server. This argument is optional.
If the network service name specified is a database name, then TNSPING attempts to contact the corresponding listener. It does not actually determine whether the database is running. Use SQL*Plus to attempt a connection to the database.
15-2 Oracle Database Net Services Administrator's Guide
Using the TNSPING Utility to Test Connectivity from the Client
The following are some examples of TNSPING.
Note:
Different platforms may have different interfaces, but the program accepts the same arguments. Invoke TNSPING for the display of the proper interface requirements.
(page 15-3) is an example of checking a listener for a database using a network service name of sales
using the
TNSPING
command.
Example 15-1 Checking a Listener with TNSPING
TNSPING sales
This produces the following message:
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 21-MAY-2016
Copyright (c) 1997, 2016 Oracle Corporation. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL =
TCP)(HOST = sales-server)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = sales.us.example.com)))
OK (10 msec)
To determine whether the listener for the sales
database is available, and to specify that TNSPING try to connect eight times and then give up, use the following syntax: tnsping sales 8
This command produces the following message:
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 21-MAY-2016
Copyright (c) 1997, 2016 Oracle Corporation. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL =
TCP)(HOST = sales-server)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = sales.us.example.com)))
OK (10 msec)
OK (0 msec)
OK (10 msec)
OK (0 msec)
OK (10 msec)
OK (10 msec)
OK (10 msec)
OK (0 msec)
(page 15-3) is an example of TNSPING attempting to check using an invalid network service name.
Example 15-2 Checking an Invalid Net Service Name with TNSPING
tnsping badname
Testing Connections 15-3
Using the TRCROUTE Utility to Test Connectivity from the Client
This attempt produces the following message:
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 21-MAY-2016
Copyright (c) 1997, 2016 Oracle Corporation. All rights reserved.
Used parameter files:
TNS-03505: Failed to resolve name
(page 15-4) is an example of output when using TNSPING to check a name that is valid, but resolves to an address where no listener is located, for example, the listener may not be started.
Example 15-3 Checking Valid Net Service Name but No Listener with TNSPING
tnsping sales
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 21-MAY-2016
Copyright (c) 1997, 2016 Oracle Corporation. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL =
TCP)(HOST = sales-server)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = sales.us.example.com)))
TNS-12541: TNS:no listener
15.3 Using the TRCROUTE Utility to Test Connectivity from the Client
The Trace Route Utility (TRCROUTE), in Linux and UNIX environments, enables administrators to discover the path or route a connection takes from a client to a server. If TRCROUTE encounters a problem, then it returns an error stack to the client instead of a single error. These additional error messages make troubleshooting easier.
TRCROUTE is different from TNSPING in that it travels as a special type of connect packet, and is routed as such. As it travels toward its destination, the TRCROUTE connect packet collects the TNS addresses of every node it travels through. If an error occurs, then TRCROUTE collects error information that shows where the error occurred. The TRCROUTE displays the information collected on the client screen. You can redirect the TRCROUTE output to a file, and print it.
The TRCROUTE uses minimal resources. It gathers information in the connect data of a special connect packet. Standard connect packets are not affected.
The server is not affected by TRCROUTE. The listener receives and processes the
TRCROUTE connect packet. It returns the information to the client by putting it into a refuse packet. The server does not need to start any new processes or deal with dummy connections.
To use the TRCROUTE utility, enter the following command: trcroute
net_service_name
(page 15-4) shows a successful trace route packet that traveled from a client to a listener.
Example 15-4 Successful Trace Route
trcroute sales
15-4 Oracle Database Net Services Administrator's Guide
Using the TRCROUTE Utility to Test Connectivity from the Client
Trace Route Utility for Linux: Version 12.1.0.1.0 - Production on 21-NOV-2012
Copyright (c) 1999, 2012 Oracle Corporation. All rights reserved.
Route of TrcRoute:
------------------
Node: Client Time and address of entry into node:
-------------------------------------------------------------
09-NOV-2012 21:48:48 ADDRESS= PROTOCOL=TCP HOST=10.150.21.136 PORT=14001
Node: Server Time and address of entry into node:
-------------------------------------------------------------
09-NOV-2012 21:48:05 ADDRESS= PROTOCOL=TCP HOST=10.150.21.136 PORT=14001
(page 15-5) shows an unsuccessful trace route packet that could not reach the listener because the listener was not up.
Example 15-5 Trace Route with Error
trcroute sales
Trace Route Utility for Linux: Version 12.1.0.1.0 - Production on 21-NOV-2012
Copyright (c) 1999, 2012 Oracle Corporation. All rights reserved.
Route of TrcRoute:
------------------
Node: Client Time and address of entry into node:
-------------------------------------------------------------
25-FEB-2012 14:43:05 ADDRESS= PROTOCOL=TCP HOST=sales-server PORT=1521
TNS-12543: TNS:unable to connect to destination
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-03601: Failed in route information collection
Testing Connections 15-5
Using the TRCROUTE Utility to Test Connectivity from the Client
15-6 Net Services Administrator's Guide
16
Troubleshooting Oracle Net Services
Oracle Net Services provides methods for understanding, testing and resolving network problems. Oracle Database includes utilities, and log and trace files for testing and diagnosing network connection and problems. The TNSPING and TRCROUTE utilities test connectivity. The log and trace files keep track of the interaction between network components as errors occur. Evaluating this information helps to diagnose and troubleshoot network problems.
Understand the common testing procedures and network errors, and outline procedures for resolving problems. Also, learn methods for logging and tracing error information to diagnose and troubleshoot more complex network problems.
•
Understanding Automatic Diagnostic Repository (page 16-1)
•
Diagnosing Oracle Net Services (page 16-6)
•
Resolving the Most Common Error Messages for Oracle Net Services
(page 16-11)
•
Troubleshooting Suggestions for Oracle Net Services
(page 16-20)
•
Example of Troubleshooting a TNS-12154 Error (page 16-21)
•
Logging Error Information for Oracle Net Services (page 16-22)
•
Tracing Error Information for Oracle Net Services
(page 16-36)
•
Contacting Oracle Support Services (page 16-64)
16.1 Understanding Automatic Diagnostic Repository
The
Automatic Diagnostic Repository (ADR)
(ADR) is a systemwide tracing and
logging central repository. The repository is a file-based hierarchical data store for depositing diagnostic information, including network tracing and logging information.
The ADR home is the unit of the ADR directory that is assigned to an instance of an
Oracle product. Each database instance has its own ADR home. Similarly, each listener, Oracle Connection Manager, and client instance has its own ADR home.
In case of a process failure, an incident is generated. The incident dump files are located in the
ADR_BASE/ADR_HOME/incident/
directory, By default, ADR_BASE is ORACLE_BASE if the ORACLE_BASE variable is set. If the variable is not set, then
ADR_BASE is
ORACLE_HOME/log
. ADR_BASE can be set to any location.
The incident dump file location can be found inside the process trace file.
The location of an ADR home is given by the following path, which starts at the ADR base directory:
Troubleshooting Oracle Net Services 16-1
Understanding Automatic Diagnostic Repository diag/
product_type
/
product_id
/
instance_id
Table 16-1 (page 16-2) lists the values of the path components for an Oracle Net
Listener instance.
Table 16-1 ADR Home Path Components for an Oracle Net Listener Instance
Path Component
product_type product_id instance_id
Value for Oracle Net Listener
tnslsnr host name listener alias name
(page 16-2) illustrates the directory hierarchy of the ADR for an Oracle
Net Listener instance. Other ADR homes for other Oracle products or components, such as Automatic Storage Management (ASM) or Oracle Database, can exist within this hierarchy, under the same ADR base.
Figure 16-1 Directory Structure for an Oracle Net Listener Instance
ADR base
ADR home
diag tnslsnr
host_name listener_alias_name
alert cdump incident trace (others)
Table 16-2 (page 16-2) lists the values of the path components for an Oracle
Connection Manager instance.
Table 16-2 ADR Home Path Components for an Oracle Connection Manager
Instance
Path Component
product_type product_id instance_id
Value for Oracle Connection Manager
netcman host name
Oracle Connection Manager instance name
(page 16-3) illustrates the directory hierarchy of the ADR for an Oracle
Connection Manager instance. Other ADR homes for other Oracle products or
16-2 Oracle Database Net Services Administrator's Guide
Understanding Automatic Diagnostic Repository components, such as Oracle ASM or Oracle Database, can exist within this hierarchy, under the same ADR base.
Figure 16-2 Directory Structure for an Oracle Connection Manager Instance
ADR base
ADR home
diag netcman
host_name cman_instance_name
alert cdump incident trace (others)
Within the ADR home directory are subdirectories where each instance, such as the database, listener, Oracle Connection Manager, or client, stores diagnostic data.
Table 16-3 (page 16-3) lists all the subdirectories shown in the preceding figure and
their contents.
Table 16-3 ADR Home Subdirectories
Subdirectory Name
alert cdump incident trace
(others)
Contents
The XML-formatted log named log.xml
.
Core files.
Multiple subdirectories, in which each subdirectory is named for a particular incident, and each contains dumps pertaining only to that incident.
Background and server process trace files, SQL trace files, and text version of the log.xml
file in the alert directory.
Other subdirectories of ADR home, which store incident packages, health monitor reports, and other information.
The
ADR_BASE
directory is the physical location in which one or more ADR homes are placed. Conceptually, it is the root directory of ADR.
Non-ADR (meaning that the DIAG_ADR_ENABLED parameter is set to
OFF
) diagnostic and tracing methods are still current and applicable but the parameters are ignored if ADR is enabled. ADR is enabled by default.
Diagnostic parameters are found in the following configuration files:
• sqlnet.ora
for clients
Troubleshooting Oracle Net Services 16-3
Understanding Automatic Diagnostic Repository
• listener.ora
for listeners
• cman.ora
for Oracle Connection Managers
Table 16-4 (page 16-4) compares usage of diagnostic parameters found in the
sqlnet.ora
file used in both ADR-based and non-ADR-based diagnostics.
Table 16-4 sqlnet.ora File Diagnostic Parameter Comparison
Parameter
ADR_BASE
TRACE_LEVEL_CLIENT
TRACE_LEVEL_SERVER
TRACE_DIRECTORY_CLIENT
TRACE_FILE_CLIENT
TRACE_UNIQUE_CLIENT
LOG_DIRECTORY_CLIENT
LOG_FILE_CLIENT
LOG_DIRECTORY_SERVER
TRACE_DIRECTORY_SERVER
TRACE_FILE_SERVER
DIAG_ADR_ENABL
ED=ON
Enabled
DIAG_ADR_ENABL
ED=OFF
Disabled
Enabled
Enabled
Disabled
Enabled
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Enabled
Enabled
Enabled
Enabled
Table 16-5 (page 16-4) compares usage of diagnostic parameters found in the
listener.ora
file used in both ADR-based and non-ADR-based diagnostics.
Table 16-5 listener.ora File Diagnostic Parameter Comparison
Parameter
ADR_BASE_listener_name
LOGGING_listener_name
TRACE_LEVEL_listener_name
TRACE_TIMESTAMP_listener_name
LOG_DIRECTORY_CLIENT_listener_name
Enabled
Disabled
LOG_FILE_CLIENT_listener_name Disabled
TRACE_DIRECTORY_CLIENT_listener_name Disabled
TRACE_FILELEN_listener_name Disabled
TRACE_FILENO_listener_name
DIAG_ADR_ENABL
ED=ON
Enabled
DIAG_ADR_ENABL
ED=OFF
Disabled
Enabled
Enabled
Enabled
Enabled
Disabled
Enabled
Enabled
Enabled
Enabled
Enabled
Enabled
16-4 Oracle Database Net Services Administrator's Guide
Understanding Automatic Diagnostic Repository
Table 16-6 (page 16-5) compares usage of diagnostic parameters found in the
cman.ora
file used in both ADR-based and non-ADR-based diagnostics.
Table 16-6 cman.ora File Diagnostic Parameter Comparison
Parameter
ADR_BASE
LOG_LEVEL
TRACE_LEVEL
TRACE_TIMESTAMP
LOG_DIRECTORY
TRACE_DIRECTORY
TRACE_FILELEN
TRACE_FILENO
DIAG_ADR_ENABL
ED=ON
Enabled
DIAG_ADR_ENABL
ED=OFF
Disabled
Enabled
Enabled
Enabled
Enabled
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Enabled
See Also:
•
Oracle Call Interface Programmer's Guide
for additional information about the location of the client ADR Home
•
Oracle Database Administrator's Guide
for additional information about
ADR
•
Oracle Database Net Services Reference
for descriptions of the diagnostic parameters
16.1.1 ADRCI: ADR Command Interpreter
ADRCI is a command-line tool that is part of the fault diagnosability infrastructure.
ADRCI enables you to do the following:
• View diagnostic data within ADR
• Package incident and problem information into a zip file for transmission to
Oracle Support Services
Diagnostic data includes incident and problem descriptions, trace files, dumps, health monitor reports, alert log entries, and so on.
ADRCI has a rich command set, and can be used in interactive mode or within scripts.
In addition, ADRCI can run scripts of ADRCI commands in the same way that
SQL*Plus runs scripts with SQL and PL/SQL commands.
To view trace files using ADRCI, enter
ADRCI
at a command line. The following are common ADRCI commands used to check a client:
Troubleshooting Oracle Net Services 16-5
Diagnosing Oracle Net Services
Client Side
adrci> SHOW ALERT adrci> SHOW BASE -product client adrci> SET BASE -product
client
adrci> SHOW TRACEFILE adrci> SHOW TRACE
trace_file
.trc
adrci> SHOW SPOOL
In the preceding commands, the
SHOW ALERT
command shows the log.xml
file in a text editor, such as VI. The
SHOW BASE -product client
command displays the value of the
ADR_BASE
directory for the client. Use that value for client in the
SET
BASE
command.
The following are common ADRCI commands used to check a server:
Server Side
adrci> SHOW BASE adrci> SHOW TRACEFILE adrci> SHOW TRACE
trace_file
.trc
Other ADRCI command options are available for a more targeted Oracle Net trace file analysis. Type
HELP
at the ADRCI prompt for help documentation.
See Also:
Oracle Database Utilities
for additional information about ADRCI
16.2 Diagnosing Oracle Net Services
Any underlying fault, noticeable or not, is reported by Oracle Net Services with an error number or message. The error number and message provide useful information for diagnosing the problem, but may not always identify the actual problem. The tasks in this section help determine which parts of Oracle Net Services do function properly rather than the parts which do not work. They also help to determine in which of the following categories the fault belongs:
• Oracle software
• Operating system layer
• Other network layers
Testing the various network layers progressively should, in most cases, uncover any problem.
This section contains the following topics:
•
(page 16-6)
•
Diagnosing Client Problems (page 16-8)
16.2.1 Diagnosing Server Problems
To start diagnosing server problems, you should answer the following questions:
16-6 Oracle Database Net Services Administrator's Guide
Diagnosing Oracle Net Services
• Is any other system such as a workstation or server able to connect to the server using Oracle Net?
• Has the server, database, or listener configuration remained the same for some time?
If you answered yes to either of the preceding questions, then go to "
If you are unsure, or answered no to any of the preceding questions, then use the tasks in this section to diagnose the problem. Diagnosing Oracle Net Services on the server involves the following tasks:
•
Task 1, Verify the Database is Running
(page 16-7)
•
Task 2, Perform a Loopback Test
(page 16-7)
Task 1 Verify the Database is Running
To check that the database is up, log in to the database and connect with a valid username and password. For example:
SQLPLUS system
Enter password:
password
A message appears, confirming that you are connected with the database. If you receive the following errors, then ask the database administrator to assist you:
•
ORA-1017: invalid U/P
•
ORA-1034: Oracle not available
Task 2 Perform a Loopback Test
A loopback test uses Oracle Net to go from the database server back to itself, bypassing the Interprocess Communication (IPC) protocol. Many network protocols provide a means of testing network connections. The PING utility can be used with a
TCP/IP network. Performing a successful loopback verifies that Oracle Net is functioning on the database server.
The following procedure describes how to perform a
the database:
1.
2.
Ensure that the listener.ora
, tnsnames.ora
, and sqlnet.ora
files exist in
the correct locations, as described in " Using Localized Management
(page 3-1)".
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
3.
4.
5.
In the navigator, expand the Directory or Local option.
Expand Service Naming to view the available network service and database names.
Select the network service name or database service.
Troubleshooting Oracle Net Services 16-7
Diagnosing Oracle Net Services
6.
Choose Command, and then select Test Net Service.
Testing assumes the listener and database are running. If they are not, then see
" Starting Oracle Net Listener and the Oracle Database Server (page 6-2)" to start
components.
During testing, a Connection Test dialog box appears, providing status and test results. A successful test results in the following message:
The connection test was successful.
7.
If the test was successful, then proceed to step 7 (page 16-8).
If the test was not successful, then do the following:
a.
b.
Ensure the database and listener are running, and then click Test.
Click Change Login to change the username and password for the connection, and then click Test.
• If the loopback test passes, then go to "
(page 16-8)".
• If the loopback test continues to fail, then contact Oracle Support Services.
Click Close to close the Connect Test dialog box.
16.2.2 Diagnosing Client Problems
Verify at least one of the following statements. This will help you decide if it is a client problem.
• The database server passed a loopback test, showing the connection worked.
• Other computers connect using Oracle Net Services to the same database.
• Connections from this workstation worked before making changes on this computer, such as the installation of a new product or modification to the network configuration.
The following procedure describes how to perform diagnostics on the client:
1.
Check that you have installed the same protocol support that was installed on the database server.
On Linux and UNIX platforms you can use the
ADAPTERS
utility to verify protocol support. On the database server, run the following command from the
ORACLE_HOME/bin
directory to display the protocol support, naming methods, and security options linked with the oracle
executable: adapters ./oracle
The adapters
utility displays output similar to the following:
Installed Oracle Net transport protocols are:
IPC
BEQ
TCP/IP
SSL
RAW
SDP/IB
16-8 Oracle Database Net Services Administrator's Guide
Diagnosing Oracle Net Services
Installed Oracle Net naming methods are:
Local Naming (tnsnames.ora)
Oracle Directory Naming
Oracle Host Naming
NIS Naming
Installed Oracle Advanced Security options are:
RC4 40-bit encryption
RC4 56-bit encryption
RC4 128-bit encryption
RC4 256-bit encryption
DES40 40-bit encryption
DES 56-bit encryption
3DES 112-bit encryption
3DES 168-bit encryption
AES 128-bit encryption
AES 192-bit encryption
AES 256-bit encryption
MD5 crypto-checksumming
SHA crypto-checksumming (for FIPS)
SHA-1 crypto-checksumming
Kerberos v5 authentication
RADIUS authentication
On the client, run the adapters
command from the
ORACLE_HOME/bin directory to display the configured Oracle protocol support, naming methods, and security options. The
ADAPTERS
utility displays output similar to the following:
Installed Oracle Net transport protocols are:
IPC
BEQ
TCP/IP
SSL
RAW
SDP/IB
Exadirect
Installed Oracle Net naming methods are:
Local Naming (tnsnames.ora)
Oracle Directory Naming
Oracle Host Naming
Installed Oracle Advanced Security options are:
RC4 40-bit encryption
RC4 56-bit encryption
RC4 128-bit encryption
RC4 256-bit encryption
DES40 40-bit encryption
DES 56-bit encryption
3DES 112-bit encryption
3DES 168-bit encryption
AES 128-bit encryption
AES 192-bit encryption
AES 256-bit encryption
MD5 crypto-checksumming
Troubleshooting Oracle Net Services 16-9
Diagnosing Oracle Net Services
SHA-1 crypto-checksumming
Kerberos v5 authentication
RADIUS authentication
Note:
RAW is an internal protocol used by Oracle Net.
See Also:
Oracle Database Administrator's Reference
for additional information about the adapters
utility
2.
Check base connectivity for underlying network transport. Oracle Net technology depends on the underlying network for a successful connection.
Table 16-7
Protocol
TCP/IP
Named Pipes
Verify that you can...
Use terminal emulation or file transfer utilities, (PING, FTP,
TELNET) from the client to the database server.
• See other computers or servers on the Microsoft network.
• Ensure that you are able to share drives within the network.
3.
4.
Ensure that the Oracle Net foundation layer and the appropriate Oracle protocol support are present by verifying that all Oracle Net Services software has been installed for the client.
Ensure that the client computer has the tnsnames.ora
and the sqlnet.ora
files in the correct locations.
See Also:
"
(page 3-1)"
5.
If any other working client computers are connecting to the selected Oracle
Database, then back up your existing files and copy both the working tnsnames.ora
and sqlnet.ora
files from the working client computer to the non-working clients. This eliminates the possibility of errors in the files.
Test the Oracle Net foundation layer. You can test using the following command to connect to SQL*Plus:
SQLPLUS
user
/
password
@
connect_string
Note:
Do not use the TNSPING utility. The TNSPING utility works like the TCP/IP ping utility and does not create and open a socket, nor does it connect with the listener. It only shows that the listener is present on the database server.
16-10 Oracle Database Net Services Administrator's Guide
Resolving the Most Common Error Messages for Oracle Net Services
6.
If the connection still fails, then do the following:
a.
Use tracing, as described in section "
Tracing Error Information for Oracle Net
b.
c.
Check the Oracle Support Services website for a specific diagnostics bulletin on the error received.
Contact Oracle Support Services.
16.3 Resolving the Most Common Error Messages for Oracle Net Services
Due to the complexity of network communications, network errors may originate from a variety of sources, for a variety of reasons. If an error occurs, then applications such as SQL*Plus, that depend on network services from Oracle Net Services, normally generate an error message.
A list of the most common network error messages follows:
•
ORA-03113: End-of-file on Communication Channel
(page 16-12)
•
ORA-12154: Could Not Resolve the Connect Identifier Specified
(page 16-12)
•
ORA-12170: Connect Timeout Occurred
(page 16-14)
•
TNS-12500 or ORA-12500: Listener Failed to Start a Dedicated Server Process
(page 16-15)
•
ORA-12514: Listener Does Not Currently Know of Service Requested in Connect
(page 16-16)
•
ORA-12520: Listener Could Not Find Available Handler for Requested Type of
(page 16-16)
•
ORA-12521: Listener Does Not Currently Know of Instance Requested in Connect
(page 16-17)
•
ORA-12525: Listener Has Not Received Client's Request in Time Allowed
(page 16-17)
•
ORA-12533: Illegal Address Parameters (page 16-18)
•
TNS-12540 or ORA-12540: TNS:Internal Limit Restriction Exceeded and
TNS-00510: Internal Limit Restriction Exceeded (page 16-18)
•
TNS-12541 or ORA-12541: TNS:No Listener (page 16-18)
•
TNS-12549 or ORA-12549: TNS:Operating System Resource Quota Exceeded and
TNS-00519: Operating System Resource Quota Exceeded
(page 16-19)
•
TNS-12560 or ORA-12560: TNS:Protocol Adapter Error Occurred (page 16-19)
•
Directory Naming Errors (page 16-19)
For information about the specific error messages, use the Oracle error tool oerr
, by entering the following command at any command line: oerr
code error_number
In the preceding command, code is the type of message, such as ORA and TNS, and
error_number
is the number associated with the error message.
Troubleshooting Oracle Net Services 16-11
Resolving the Most Common Error Messages for Oracle Net Services
See Also:
Oracle Database Error Messages
for a complete listing of error messages
16.3.1 ORA-03113: End-of-file on Communication Channel
This message indicates that an error has occurred on the database server.
Check the alert_sid.log
file on the server. An unexpected end of file was processed on the communication channel. This may be an indication that the communications link may have gone down at least temporarily, or it may indicate that the server has gone down.You may need to modify your retransmission count.
16.3.2 ORA-12154: Could Not Resolve the Connect Identifier Specified
This message indicates that a connection to a database or other service was requested using a connect identifier, and the connect identifier specified could not be resolved into a connect descriptor using one of the naming methods configured. For example, if the type of connect identifier used was a network service name then the network service name could not be found in a naming method repository, or the repository could not be located or reached.
Perform the following steps:
1.
Check the type of naming adapters listed in the NAMES.DIRECTORY_PATH
parameter in the sqlnet.ora
file. If none are configured, then use the adapters command to determine which adapters are in use. The following example shows the adapters:
$ adapters
...
Installed Oracle Net naming methods are:
Local Naming (tnsnames.ora)
Oracle Directory Naming
Oracle Host Naming
NIS Naming
The network service name given in the connect string should be defined for at least one of the naming methods.
2.
Check the resolution path for each adapter for possible problems. For example, ensure that the name given in the connect string is correct and complete, using the full name of the network service if necessary.
In addition to the preceding steps, perform the steps depending on your naming methods:
•
ORA-12154 Error When Using the Local Naming Method
(page 16-12)
•
ORA-12154 Error When Using the Directory Naming Method
(page 16-13)
•
ORA-12154 Error When Using the Easy Connect Naming Method
(page 16-13)
•
ORA-12154 Error When Using the External Naming Method (page 16-14)
16.3.2.1 ORA-12154 Error When Using the Local Naming Method
Perform the following steps when using the local naming method:
16-12 Oracle Database Net Services Administrator's Guide
Resolving the Most Common Error Messages for Oracle Net Services
1.
2.
3.
4.
Verify that the
tnsnames.ora
file exists and is in the correct location. The location is either the
ORACLE_HOME/network/admin
directory or the directory specified by the TNS_ADMIN environment variable.
Verify there is an entry in the tnsnames.ora
file for the name given in the connect string. This network service name should match the name in the tnsnames.ora
file exactly if the name is simple and there is not
NAMES_DEFAULT_DOMAIN in the sqlnet.ora
file, or the network service name is a fully-qualified name. If the network service name in the connect string is simple, then check the NAMES_DEFAULT_DOMAIN parameter in the sqlnet.ora
file. Its value is appended to the network service name given in the connect string. This fully-qualified name should be the entry in the tnsnames.ora
file.
If you are connecting from a login dialog box, then verify that you are not placing an at sign (@) before the connect network service name.
Activate client tracing, and repeat the operation.
16.3.2.2 ORA-12154 Error When Using the Directory Naming Method
Perform the following steps when using the directory naming method:
1.
Verify the ldap.ora
file exists and is in the correct location. The following directories are searched for ldap.ora
file in the order given. The ldap.ora
file found will be used.
2.
3.
4.
5.
• The directory specified by the TNS_ADMIN environment variable.
• The
ORACLE_HOME/network/admin
directory.
• The directory specified by the LDAP_ADMIN environment variable.
• The
ORACLE_HOME/ldap/admin
directory.
Verify that the parameters defined in the ldap.ora
file are correct, as follows:
• The DIRECTORY_SERVERS parameter defines the correct host and port for one or more valid LDAP servers.
• The DEFAULT_ADMIN_CONTEXT parameter defines the location of the
Oracle Context in this directory which should include the network service entry.
If the ldap.ora
file does not exist, then these parameters are resolved using automatic discovery.
Verify that the LDAP server host and port are defined in DNS.
Verify that the directory has the default Oracle Context defined.
Use the ldapsearch utility or a directory administration tool to verify that the network service object exists in the Oracle Context at the location given by the value of the DEFAULT_ADMIN_CONTEXT parameter.
16.3.2.3 ORA-12154 Error When Using the Easy Connect Naming Method
Verify that the host name give is correct, and is defined in the local host name resolution service, such as local hosts file, DNS, and so on.
Troubleshooting Oracle Net Services 16-13
Resolving the Most Common Error Messages for Oracle Net Services
16.3.2.4 ORA-12154 Error When Using the External Naming Method
Perform the following steps when using the external naming method:
1.
2.
Verify that the NIS file for tnsnames
map is properly set up.
Check that the network service name matches the tnsnames
entry as described in
" ORA-12154 Error When Using the Local Naming Method (page 16-12)".
See Also:
•
" Example of Troubleshooting a TNS-12154 Error
(page 16-21)" for additional information about troubleshooting the error
•
(page 3-1)" for configuration file location information
•
(page 8-1) for naming information
16.3.3 ORA-12170: Connect Timeout Occurred
This message indicates that the client failed to establish a connection and complete authentication in the time specified by the
SQLNET.INBOUND_CONNECT_TIMEOUT parameter in the sqlnet.ora
file. This error may be a result of network or system delays, or it may indicate that a malicious client is trying to cause a denial-of-service attack on the database server.
• If the error occurred due to system or network delays that are normal for the particular environment, then perform the following steps:
1.
Turn on tracing to determine which clients are timing out.
See Also:
"
Tracing Error Information for Oracle Net Services (page 16-36)"
2.
Reconfigure the SQLNET.INBOUND_CONNECT_TIMEOUT,
SQLNET.SEND_TIMEOUT, or SQLNET.RECV_TIMEOUT parameters in the sqlnet.ora
file to larger values.
• If you suspect a malicious client, then perform the following steps:
1.
2.
Restrict access to the client. You can configure parameters for access rights in the sqlnet.ora
file.
Locate the IP address of the client in the sqlnet.log
file on the database server to identify the source. Keep in mind that an IP address can be forged.
For example, the following sqlnet.log
excerpt shows a client IP address of
192.0.2.35
.
Fatal NI connect error 12170.
VERSION INFORMATION:
TNS for Linux: Version 12.2.0.1.0
16-14 Oracle Database Net Services Administrator's Guide
Resolving the Most Common Error Messages for Oracle Net Services
Oracle Bequeath NT Protocol Adapter for Linux: Version 12.2.0.1.0
TCP/IP NT Protocol Adapter for Linux: Version 12.2.0.1.0
Time: 03-MAY-2016 13:51:12
Tracing to file: /ora/trace/svr_13279.trc
Tns error struct:
nr err code: 0
ns main err code: 12637
TNS-12637: Packet receive failed
ns secondary err code: 12604
nt main err code: 0
nt secondary err code: 0
nt OS err code: 0
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=192.0.2.35)(PORT=52996))
If the time out occurs before the IP address can be retrieved by the database server, then enable listener tracing to determine the client that made the request.
See Also:
•
" Limiting Resource Consumption by Unauthorized Users (page 14-10)"
for additional information about setting the
SQLNET.INBOUND_CONNECT_TIMEOUT parameter
•
" Settings for Database Access Control (page 12-5)"
•
" Tracing Error Information for Oracle Net Services (page 16-36)"
16.3.4 TNS-12500 or ORA-12500: Listener Failed to Start a Dedicated Server Process
These messages indicate that the listener failed to start the Oracle program. Possible reasons include:
• The maximum number of processes allowed for a single user was exceeded
• The listener does not have execute permission on the Oracle program
• The associated Microsoft Windows service is not started
In some cases, these errors can be caused by the same conditions which cause the following errors:
• TNS-12549 or ORA-12549
• TNS-00519
• TNS-12540 or ORA-12540
• TNS-00510
• TNS-12560 or ORA-12560
Perform the appropriate action:
• Increase the number of processes by setting the PROCESSES parameter in the database initialization file to a larger value.
• Check the listener.log
file for detailed error stack information.
Troubleshooting Oracle Net Services 16-15
Resolving the Most Common Error Messages for Oracle Net Services
16.3.5 ORA-12514: Listener Does Not Currently Know of Service Requested in Connect
Descriptor
This message indicates that the listener received a request to establish a connection to a database or other service. The connect descriptor received by the listener specified a service name for a service (usually a database service) that has either not yet dynamically registered with the listener or has not been statically configured for the listener. This may be a temporary condition such as after the listener has started, but before the database instance has registered with the listener.
Perform the following steps:
1.
Wait a moment, and then try to connect a second time.
2.
3.
4.
Check which services are currently known by the listener by running the Listener
Control utility
STATUS
or
SERVICES
command.
Check that the SERVICE_NAME parameter in the connect descriptor specifies a service name known by the listener.
Check for an event in the listener.log
file.
See Also:
•
" Determining the Current Status of a Listener (page 9-16)" and
" Monitoring Services of a Listener (page 9-18)"
•
" Analyzing Listener Log Files
(page 16-29)"
16.3.6 ORA-12520: Listener Could Not Find Available Handler for Requested Type of
Server
This message indicates that the type of service handler requested by the client is incorrect or not registered for the requested SERVICE_NAME/INSTANCE_NAME parameters, or the database instance is not registered with the listener.
If you suspect the problem is the wrong type of service handler, then perform the following steps:
1.
If ( server=value
) is set in the connect descriptor, then ensure that the value is set to the appropriate service handler type for the database, that is, dedicated for dedicated server or shared
for dispatchers. You can use the Listener Control utility
SERVICES
command to see what service handlers are currently registered with the listener.
2.
3.
If the USE_DEDICATED_SERVER parameter is set to
ON
in the sqlnet.ora
file, then ensure the database is configured to use dedicated servers. If it is not, then set this parameter to
OFF
.
Ensure that the database instance is running. If the instance not running, then start it so that it can register with the listener.
16-16 Oracle Database Net Services Administrator's Guide
Resolving the Most Common Error Messages for Oracle Net Services
See Also:
"
Monitoring Services of a Listener
(page 9-18)" for additional information about service handlers
16.3.7 ORA-12521: Listener Does Not Currently Know of Instance Requested in Connect
Descriptor
This message indicates that the instance name in the connect descriptor is incorrect, or the database instance is not registered with the listener.
Perform the following steps:
1.
2.
Ensure the service name specified in the connect descriptor is correct.
Ensure the database instance is running. If the instance not running, then start it so that it can register with the listener. You can use the Listener Control utility
SERVICES
command to see what instances are currently registered with the listener.
See Also:
"
Monitoring Services of a Listener
(page 9-18)" for additional information about
SERVICES
command
16.3.8 ORA-12525: Listener Has Not Received Client's Request in Time Allowed
This message indicates that the client failed to complete its connect request in the time specified by the INBOUND_CONNECT_TIMEOUT_listener_name parameter in the listener.ora
file. This error may be a result of network or system delays, or it may indicate that a malicious client is trying to cause a denial-of-service attack on the listener.
• If the error occurred due to system or network delays that are normal for the particular environment, then reconfigure the
INBOUND_CONNECT_TIMEOUT_listener_name parameter in listener.ora
to a larger value.
• If you suspect a malicious client, then perform the following steps:
1.
Locate the IP address of the client in the listener.log
file to identify the source. Keep in mind that an IP address can be forged.
For example, the following listener.log
file excerpt shows a client IP address of
192.0.2.35
.
03-MAY-2012 16:42:35 * <unknown connect data> *
(ADDRESS=(PROTOCOL=tcp)(HOST=192.0.2.35)(PORT=53208)) * establish *
<unknown sid> * 12525
TNS-12525: TNS:listener has not received client's request in time allowed
TNS-12604: TNS: Application timeout occurred
2.
Restrict access to the client. You can configure parameters for access rights in the sqlnet.ora
file.
Troubleshooting Oracle Net Services 16-17
Resolving the Most Common Error Messages for Oracle Net Services
See Also:
•
" Limiting Resource Consumption by Unauthorized Users (page 14-10)"
for additional information about setting the
INBOUND_CONNECT_TIMEOUT_listener_name parameter
•
" Settings for Database Access Control (page 12-5)"
16.3.9 ORA-12533: Illegal Address Parameters
This message indicates that the protocol specific parameters in the ADDRESS section of the designated connect descriptor are incorrect.
Correct the protocol address.
Note:
This error is often caused by hand-editing of the tnsnames.ora
file. Only edit the tnsnames.ora
file using Oracle Enterprise Manager Cloud Control or Oracle Net Manager.
See Also:
Oracle Database Net Services Reference
for correct protocol syntax
16.3.10 TNS-12540 or ORA-12540: TNS:Internal Limit Restriction Exceeded and
TNS-00510: Internal Limit Restriction Exceeded
These messages indicate that an internal limit has been exceeded. Possible limits include the following:
• Number of open connections that Oracle Net can process simultaneously
• Number of memory buffers that can be used simultaneously
• Number of processes a particular database instance is allowed
The first two are examples of hard limits. The third is an example of a limit which can be increased by setting PROCESSES parameter in the database initialization file to a larger value. In this case, a TNS-12500 or ORA-12500 error is also returned. In some cases, these errors can be caused by the same conditions which cause TNS-12549 or
ORA-12549, and TNS-00519 errors.
Wait for the open connections to close and retry. If the error persists, then check the sqlnet.log
or listener.log
file for detailed error stack information.
16.3.11 TNS-12541 or ORA-12541: TNS:No Listener
These messages indicate that the connection request could not be completed because the listener is not running.
Perform the following actions:
16-18 Oracle Database Net Services Administrator's Guide
Resolving the Most Common Error Messages for Oracle Net Services
• Ensure the supplied destination address matches one of the addresses used by the listener.
• Verify the listener is running at the address specified by the request.
• Ensure the listener is listening on the host and port specified by the request.
• Verify the client is pointing to the listener.
16.3.12 TNS-12549 or ORA-12549: TNS:Operating System Resource Quota Exceeded and TNS-00519: Operating System Resource Quota Exceeded
These messages indicate that a quota or hard limit imposed by the operating system has been exceeded.
Possible limits include:
• The maximum number of processes allowed for a single user
• The operating system is running low on paging space
Perform the appropriate action:
• Increase the number of processes by setting the PROCESSES parameter in the database initialization file to a larger value.
• Check the sqlnet.log
or listener.log
file for detailed error stack information, such as an operating system error code to help identify which quota has been exceeded.
16.3.13 TNS-12560 or ORA-12560: TNS:Protocol Adapter Error Occurred
These messages indicate that there was an error when using a particular protocol. This error may be due to incorrect configuration of an ADDRESS parameter or may occur due to errors returned from the underlying protocol or operating system interface.
In some cases, these errors are caused by the same conditions which cause TNS-00510,
TNS-00519, TNS-12540, ORA-12540, TNS-12549 or ORA-12549 errors.
These errors occur on Microsoft Windows systems only. Perform the following actions:
1.
2.
3.
4.
5.
6.
Select Run from the Microsoft Windows Start menu.
Enter
MSCONFIG
in the Open field.
Go to the Services tab.
Enable
OracleServicesid
if it is disabled.
Restart the computer.
Check that Oracle Services started.
16.3.14 Directory Naming Errors
Directory naming issues associated with connectivity errors for database service or network service name entries in a directory server require analysis of the data. You can analyze the data contained within a directory server with the ldifwrite command line tool. The ldifwrite
tool is an Oracle Internet Directory tool.
Troubleshooting Oracle Net Services 16-19
Troubleshooting Suggestions for Oracle Net Services
The ldifwrite
tool can be used to convert all or part of the information residing in a
ldifwrite
tool performs a subtree search, including all entries following the specified
The ldifwrite
tool syntax is as follows: ldifwrite -c
net_service_name/database_service
-b
base_DN
-f
ldif_file
ldifwrite
tool arguments and descriptions for each.
Table 16-8 ldifwrite Arguments
Argument
-c net_service_name/
database_service
-b base_DN
-f ldif_file
Description
The network service name or database service name that connects to the directory server.
The base of the subtree to be written out in LDIF format.
The output file name.
The following example writes all the directory naming entries under dc=us,dc=example,dc=com
to the output1.ldi
file: ldifwrite -c ldap -b "dc=us,dc=example,dc=com" -f output.ldif
Note:
Check the ldap.ora
file to determine the base_DN value. It is the same as the
DEFAULT_ADMIN_CONTEXT entry in the ldap.ora
file.
16.4 Troubleshooting Suggestions for Oracle Net Services
The following suggestions may be useful when diagnosing network problems:
• Use the node or network address during configuration instead of the name of the server computer. This eliminates any internal lookup problems and make the connection slightly faster.
• If you are using TCP/IP addresses, then use the IP address rather than the host name. For example, change the
HOST=server_name
line in the tnsnames.ora
file to the IP address, such as
HOST=192.0.2.5
.
•
Perform a loopback test on the server as described in Task 2, Perform a Loopback
Test (page 16-7). If the test passes, then use FTP to send the
tnsnames.ora
and sqlnet.ora
files to the client.
• Check the systems between the client and the server. If it is a wide area network
(WAN), then identify any intermediate systems that may not work correctly. If all computers are fine, then the problem may be a timing issue.
• Verify whether there is a timing issue. Timing issues are associated with an
ORA-12535
error in the client log files.
To resolve a timing issue, try speeding up the connection by using exact addresses instead of names and increase the
16-20 Oracle Database Net Services Administrator's Guide
Example of Troubleshooting a TNS-12154 Error
INBOUND_CONNECT_TIMEOUT_listener_name parameter in the listener.ora
file. The default value for this parameter is 10 seconds.
• Determine which Oracle applications are failing. SQL*Plus may work, but CASE tools may not. If you determine the problem is a data volume issue, then try to transfer a large (5 MB) file with the base connectivity.
16.4.1 Questions to Consider When Troubleshooting Oracle Net Services
The following questions can help diagnose a problem:
• Do all computers have a problem, or is it just one?
If one computer works and another does not, and the same software (Oracle and third-party products) is installed on each computer, then, if possible, swap out the network cables to see if the problem occurs on the second client. If it does occur, then it indicates that the problem has something to do with the client/server connection and is not local to the client.
• What kind of connections exist between the client and the server, for example, X.
25, ISDN, or leased line?
Sniffers and LAN analyzers are useful for locating intermittent connection failures, and detecting time outs and resent packets. You can also see which side is waiting for a response.
16.5 Example of Troubleshooting a TNS-12154 Error
This section offers some solutions for the TNS-12154 error. The TNS-12154 error is encountered when SQL*Net cannot find the connect identifier specified for a connection in the tnsnames.ora
file or other naming adapter.
Before attempting to resolve the problem, it may be helpful to print out or view the tnsnames.ora
file and the sqlnet.ora
file. Looking at these files at the same time is helpful because references are made to both.
In this example, the tnsnames.ora
and sqlnet.ora
files are located in the default network administration directory on the client system.
Be sure that the tnsnames.ora
file and the sqlnet.ora
file resemble the following examples.
(page 16-21) shows an example of a tnsnames.ora
file.
Example 16-1 tnsnames.ora Sample
DEV1.WORLD =
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)
(HOST = 192.0.2.56)
(PORT = 1521)
)
(CONNECT_DATA =
(SERVICE_NAME = sales.example.com)
)
)
(page 16-22) shows an example of a sqlnet.ora
file.
Troubleshooting Oracle Net Services 16-21
Logging Error Information for Oracle Net Services
Example 16-2 sqlnet.ora Sample
TRACE_LEVEL_CLIENT = OFF
SQLNET.AUTHENTICATION_SERVICES = (NONE)
NAMES.DIRECTORY_PATH = (TNSNAMES)
AUTOMATIC_IPC = OFF
The alias in
(page 16-21) is
DEV1.WORLD
. However, the
NAMES.DEFAULT_DOMAIN = WORLD parameter does not exist in
(page 16-22). To fix this problem, add the NAMES.DEFAULT_DOMAIN = WORLD parameter anywhere in the sqlnet.ora
file. Save the file, and try the connection again.
16.6 Logging Error Information for Oracle Net Services
All errors encountered by Oracle Net Services are appended to a log file for evaluation by a network or database administrator. The log file provides additional information for an administrator about on-screen error messages. The error stack in the log file shows the state of the software at various layers.
To ensure that all errors are recorded, logging cannot be disabled on clients or name servers. Furthermore, only an administrator may replace or erase log files. The log file for the listener includes audit trail information about every client connection request, and most listener control commands.
This section contains the following topics:
•
Oracle Net Error Stacks (page 16-22)
•
Oracle Net Services Log File Names
(page 16-24)
•
(page 16-24)
•
Setting Logging Parameters in Configuration Files (page 16-27)
•
Setting Logging During Control Utilities Runtime
(page 16-29)
•
(page 16-29)
•
Analyzing Listener Log Files (page 16-29)
•
Analyzing Oracle Connection Manager Logs (page 16-33)
16.6.1 Oracle Net Error Stacks
Log files provide information contained in an error stack. An error stack refers to the information that is produced by each layer in an Oracle communications stack as the result of a network error.
The error stack components are described in Table 16-9
(page 16-22).
Table 16-9 Error Stack Components
Error Stack Component
NI
Description
Network Interface. This layer provides a generic interface for
Oracle clients, servers, or external processes to access Oracle
Net functions. The NI layer handles the "break" and "reset" requests for a connection.
16-22 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
Table 16-9 (Cont.) Error Stack Components
Error Stack Component
NS
NA
NT
Description
Network Session (main and secondary layers). These layers receive requests from NI, and settle all generic computer-level connectivity issues, such as:
• The location of the server or destination (open, close functions).
• Whether one or more protocols are involved in the connection (open, close functions).
• How to handle interrupts between client and server based on the capabilities of each (send, receive functions).
Network Authentication. This layer negotiates authentication and encryption requirements.
Network Transport (main, secondary, and operating system layers). These layers map Oracle Net foundation layer functionality to industry-standard protocols.
16.6.1.1 Understanding Error Stack Messages
Suppose that a user of a client application tries to establish a connection with a database server using Oracle Net and TCP/IP, by entering the following commands:
SQLPLUS [email protected]
Enter password:
password
When the commands are entered, the following error displays:
ORA-12543: TNS:Unable to connect to destination
This message indicates that the connection to the server failed because the database could not be contacted. Although the application displays only a one-line error message, an error stack that is much more informative is recorded in the log file by the network layer.
On the client side, the sqlnet.log
(page 16-23) contains an error stack corresponding to the
ORA-12543
error.
Example 16-3 sqlnet.log File
Fatal OSN connect error 12543, connecting to:
(DESCRIPTION=(CONNECT_DATA=(SID=trace)(CID=(PROGRAM=)
(HOST=lala)(USER=scott)))(ADDRESS_LIST=(ADDRESS=
(PROTOCOL=ipc)(KEY=trace))(ADDRESS=(PROTOCOL=tcp)
(HOST=lala)(PORT=1521))))
VERSION INFORMATION:
TNS for Linux:
Oracle Bequeath NT Protocol Adapter for Linux:
Unix Domain Socket IPC NT Protocol Adaptor for Linux:
TCP/IP NT Protocol Adapter for Linux:
Tracing to file: /home/db_tracefiles/trace_admin.trc
Tns error struct:
TNS-12543: TNS:unable to connect to destination
ns main err code: 12541
TNS-12541: TNS:no listener
Troubleshooting Oracle Net Services 16-23
Logging Error Information for Oracle Net Services
ns secondary err code: 12560
nt main err code: 511
TNS-00511: No listener
nt secondary err code: 61
nt OS err code: 0
16.6.2 Oracle Net Services Log File Names
Each Oracle Net Services component produces its own log file. When using ADR, the default, the log file names are log.xml
in the appropriate alert directory.
(page 16-24) lists the default log file names and lists the components that generate the log files that appear in the
ADR/diag/instance_name/trace
directory.
Table 16-10 Log File Names When Using ADR
Component
Listener
Client or database server
Oracle Connection Manager listener
Oracle Connection Manager
process
Oracle Connection Manager
Connection Manager Administration)
Oracle Connection Manager alert log
Log File
listener.log
sqlnet.log
instance-name_pid.log
instance-name_cmgw_pid.log
instancename_cmadmin_pid.log
instance-name_alert.log
16.6.3 About the Logging Parameters
Parameters that control logging, including the type and amount of information logged, and the location where the files are stored, are set in the configuration file of
each network component as described in Table 16-11 (page 16-24).
Table 16-11 Location of Log Parameters
Network Component
Oracle Connection Manager processes
Listener
Client
Database server
Configuration File
cman.ora
listener.ora
sqlnet.ora
sqlnet.ora
Note:
If the ADR_ENABLED parameter is set to
ON
, then all logging parameters are set by ADR. Using Oracle Net Manager to change the parameters will not work.
This section contains the following topics:
16-24 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
•
(page 16-25)
•
(page 16-25)
•
(page 16-26)
See Also:
Oracle Database Net Services Reference
for additional information about the parameters
16.6.3.1 sqlnet.ora Log Parameters
(page 16-25) describes the log parameters settings that can be set in the sqlnet.ora
file.
Table 16-12 sqlnet.ora Log Parameters
sqlnet.ora Parameter
ADR_BASE
Oracle Net Manager
Field
You must set this parameter manually.
DIAG_ADR_ENABLED You must set this parameter manually.
LOG_DIRECTORY_CLI
ENT
Client Information:
Log Directory
LOG_DIRECTORY_SE
RVER
LOG_FILE_CLIENT
LOG_FILE_SERVER
Server Information:
Log Directory
Client Information:
Log File
You must set this parameter manually.
Description
The ADR_BASE parameter specifies the base directory for storing tracing and logging incidents.
Use this parameter when DIAG_ADR_ENABLED is set to
ON
.
The DIAG_ADR_ENABLED parameter indicates whether
ADR tracing is enabled.
When the DIAG_ADR_ENABLED parameter is set to
OFF
, non-ADR file tracing is used.
The destination directory for the client log file. By default, the client directory is the current working directory. This parameter is disabled when ADR_ENABLED is set to
ON
.
The destination directory for the database server log files. By default the server directory is
ORACLE_HOME/network/log
.
This parameter is disabled when ADR_ENABLED is set to
ON
.
The name of the log file for the client. By default the log name is sqlnet.log
.
The name of the log file for the database server. By default the log name is sqlnet.log
.
16.6.3.2 listener.ora Log Parameters
(page 16-26) describes the log parameters settings that can be set in the listener.ora
file.
Troubleshooting Oracle Net Services 16-25
Logging Error Information for Oracle Net Services
Table 16-13 listener.ora Log Parameters
listener.ora Parameter
ADR_BASE_listener_name
Oracle Net Manager
Field
You must set this parameter manually.
DIAG_ADR_ENABLED_listener_n
ame
You must set this parameter manually.
LOG_DIRECTORY_listener_name
LOG_FILE_listener_name
Log File
Description
The ADR_BASE_listener_name parameter specifies the base directory for storing which tracing and logging incidents.
Use when DIAG_ADR_ENABLED_listener_name is set to
ON
.
The DIAG_ADR_ENABLED_listener_name parameter indicates whether ADR tracing is enabled.
When DIAG_ADR_ENABLED_listener_name is set to
OFF
, non-ADR file tracing is used.
The destination directory and file for the log file that is automatically generated for listener events.
By default the directory is
ORACLE_HOME/ network/log
, and the file name is listener.log
. These parameters are disabled when ADR_ENABLED is set to
ON
.
16.6.3.3 cman.ora Log Parameters
(page 16-26) describes the log parameters settings that can be set in the cman.ora
file.
Table 16-14 cman.ora Log Parameters
cman.ora Parameter
ADR_BASE
DIAG_ADR_ENABLED
EVENT_GROUP
Description
The ADR_BASE parameter specifies the base directory for storing tracing and logging incidents.
Use this parameter when DIAG_ADR_ENABLED is set to
ON
.
The DIAG_ADR_ENABLED parameter indicates whether ADR tracing is enabled.
When the DIAG_ADR_ENABLED parameter is set to
OFF
, non-
ADR file tracing is used.
The event groups that are logged. Multiple events may be designated using a comma-delimited list. This parameter accepts the following values:
•
INIT_AND_TERM
: initialization and termination
•
MEMORY_OPS
: memory operations
•
CONN_HDLG
: connection handling
•
PROC_MGMT
: process management
•
REG_AND_LOAD
: registration and load update
•
WAKE_UP
: events related to CMADMIN wakeup queue
•
TIMER
: gateway timeouts
•
CMD_PROC
: command processing
•
RELAY
: events associated with connection control blocks
16-26 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
Table 16-14 (Cont.) cman.ora Log Parameters
cman.ora Parameter
LOG_DIRECTORY
LOG_LEVEL
Description
The destination directory for log files.
By default, the directory is
ORACLE_HOME/network/log
.
This parameter is disabled when ADR_ENABLED is set to
ON
.
The level of logging. Four levels are supported:
• off
(default): no logging
• user
: user log information
• admin
: administrative log information
• support
: Oracle Support Services information
16.6.4 Setting Logging Parameters in Configuration Files
You configure logging parameters for the sqlnet.ora
file with Oracle Net Manager and for the listener.ora
file with either Oracle Enterprise Manager Cloud Control or Oracle Net Manager. You must manually configure cman.ora
file logging parameters.
This section contains the following topics:
•
Setting Parameters for the sqlnet.ora File Using Oracle Net Manager (page 16-27)
•
Setting Parameters for the listener.ora File Using Oracle Enterprise Manager
•
Setting Parameters for the listener.ora File Using Oracle Net Manager
(page 16-28)
16.6.4.1 Setting Parameters for the sqlnet.ora File Using Oracle Net Manager
The following procedure describes how to set the logging parameters in the sqlnet.ora
file.
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
In the navigator pane, expand Profile under the Local heading.
From the list in the right pane, select General.
Click the Logging tab.
Specify the settings.
6.
Choose Save Network Configuration from the File menu.
The name of the log file is sqlnet.log
.
Troubleshooting Oracle Net Services 16-27
Logging Error Information for Oracle Net Services
16.6.4.2 Setting Parameters for the listener.ora File Using Oracle Enterprise Manager
Cloud Control
The following procedure describes how to set the logging parameters in the listener.ora
file using Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Click Go to display the Listeners page.
Select a listener, and then click Edit to display the Edit Listeners page.
Click the Logging & Tracing tab.
6.
Specify the settings.
7.
Click OK.
The name of the log file is listener.log
.
16.6.4.3 Setting Parameters for the listener.ora File Using Oracle Net Manager
The following procedure describes how to set the logging parameters in the listener.ora
file using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
In the navigator pane, expand Listeners under the Local heading.
Select a listener.
From the list in the right pane, select General.
Click the Logging and Tracing tab.
6.
Specify the settings.
7.
Choose Save Network Configuration from the File menu.
The name of the log file is listener.log
.
16-28 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
See Also:
Oracle Database Net Services Reference
16.6.5 Setting Logging During Control Utilities Runtime
You can set logging during control utility runtime. Setting logging with a control utility does not set parameters in the
*.ora
files, and the setting is only valid for the control utility session.
The following settings can be set for a control utility:
• For a listener, use the
SET LOG_FILE
and
SET LOG_DIRECTORY
commands from the Listener Control utility.
• For an Oracle Connection Manager, use the
SET LOG_DIRECTORY
,
SET
LOG_LEVEL
, and
SET EVENT
commands from the Oracle Connection Manager control utility.
Note:
If the ADR_ENABLED parameter is set to
ON
, then all logging parameters are set by ADR. Using Oracle Connection Manager to change the parameters will not work.
See Also:
Oracle Database Net Services Reference
16.6.6 Using Log Files
The following procedure describes how to use a log file to diagnose a network error:
1.
Review the log file for the most recent error number received from the application. This is usually the last entry in the log file.
2.
3.
4.
Starting from the bottom of the file, locate the first nonzero entry in the error report. This is usually the actual cause.
If that error does not provide the information, then review the next error in the log until you locate the correct error information.
If the cause of the error is still not clear, then turn on tracing and repeat the command that produced the error message.
16.6.7 Analyzing Listener Log Files
This section describes what is recorded in the listener log file. This section contains the following topics:
•
Listener Log Audit Trail Information (page 16-30)
•
Listener Service Registration Event Information
(page 16-31)
•
Listener Direct Hand-Off Information
(page 16-32)
Troubleshooting Oracle Net Services 16-29
Logging Error Information for Oracle Net Services
•
Listener Subscription for ONS Node Down Event Information
(page 16-33)
•
Listener Oracle Clusterware Notification Information
(page 16-33)
16.6.7.1 Listener Log Audit Trail Information
The listener log file contains audit trail information that enables you to collect and analyze network usage statistics, as well as information indicating the following:
• A client connection request
• A
RELOAD
,
START
,
STOP
,
STATUS
, or
SERVICES
command issued by the Listener
Control utility
You can use the audit trail information to view trends and user activity by first storing it in a table and then collating it in a report format. To import the data into a table, use an import utility such as SQL*Loader.
16.6.7.1.1 Format of the Listener Log Audit Trail
The audit trail formats text into the following fields:
Timestamp * Connect Data [* Protocol Info] * Event [* SID | Service] * Return Code
Properties of the audit trail are as follows:
• Each field is delimited by an asterisk (
*
).
• Protocol address information and service name or SID information appear only when a connection is attempted.
• A successful connection or command returns a code of zero.
• A failure produces a code that maps to an error message.
(page 16-30) shows a log file excerpt with
RELOAD
command request.
Example 16-4 Listener Log Event for Successful RELOAD Request
14-MAY-2012 00:29:54 *
(connect_data=(cid=(program=)(host=sales-server)(user=jdoe))(command=reload)
(arguments=64)(service=listener)(version=135290880))
* reload * 0
(page 16-30) shows a log file excerpt with a successful connection request.
Example 16-5 Listener Log Events for a Successful Connection Request
14-MAY-2012 15:28:58 *
(connect_data=(service_name=sales.us.example.com)(cid=(program=)(host=sales-server)
(user=jdoe)))
* (address=(protocol=tcp)(host=192.0.2.35)(port=41349)) * establish
* sales.us.example.com * 0
(page 16-31) shows a log file excerpt with a successful execution of the
STATUS
command by host sales-server
. It is followed by an unsuccessful connection attempt by a client with an IP address of
192.0.2.35
. This connection
attempt resulted in an ORA-12525: Listener Has Not Received Client's Request in Time
(page 16-17) error message. This error occurs when a client fails to complete its connection request in the time specified by the
16-30 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
INBOUND_CONNECT_TIMEOUT_listener_name parameter in the listener.ora
file. This client could be attempting a denial-of-service attack on the listener.
Example 16-6 Listener Log Events for an Unsuccessful Connection Request
03-MAY-2012 16:41:57 *
(CONNECT_DATA=(CID=(PROGRAM=)(HOST=sales-server)(USER=jdoe))(COMMAND=status)
(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=153092352)) * status * 0
03-MAY-2012 16:42:35 * <unknown connect data> *
(ADDRESS=(PROTOCOL=tcp)(HOST=192.0.2.35)(PORT=53208)) * establish *
<unknown sid> * 12525
TNS-12525: TNS:listener has not received client's request in time allowed
TNS-12604: TNS: Application timeout occurred
See Also:
Oracle Database Error Messages
for a complete listing of error messages
16.6.7.2 Listener Service Registration Event Information
The listener records service registration events. During service registration, the
process provides the listener with information about the following:
• Service names for each running instance of the database
• Instance names of the database
• Service handlers (dispatchers or dedicated servers) available
• Dispatcher, instance, and node load information
• Dynamic listening endpoints
The recorded service registration-related events listed in Table 16-15
(page 16-31) are listed in the listener.log
file:
Table 16-15 Service Registration Event Log Information
Event
service_register service_update service_died
Description
The listener received registration information for an instance.
The listener received updated registration information for a particular instance, such as dispatcher or instance load information.
The listener lost its connection to Listener Registration (LREG).
All registration information for the instance is discarded. Clients are unable to connect to the instance until LREG registers it again.
16.6.7.2.1 Format of the Listener Service Registration Information
The service registration events are formatted into the following fields:
Timestamp * Event * Instance Name * Return Code
Properties of service registration fields are as follows:
Troubleshooting Oracle Net Services 16-31
Logging Error Information for Oracle Net Services
• Each field is delimited by an asterisk (
*
).
• It is normal for the events to appear multiple times in a row for one instance.
• A successful registration returns a code of zero, meaning the client can connect to the instance.
• A failure produces a code that maps to an error message.
(page 16-32) shows a log file with service registration events. The listener is able to receive a client request after a successful service_register
event, but is unable to receive client requests after a service_died
event.
Example 16-7 Listener Log with Service Registration Events
-------------------------------
14-MAY-2012 15:28:43 * service_register * sales * 0
14-MAY-2012 15:28:43 * service_register * sales * 0
14-MAY-2012 15:28:58 *
(connect_data=(service_name=sales.us.example.com)
(cid=(program=)(host=sales-server)(user=jdoe)))
* (address=(protocol=tcp)(host=192.0.2.35)(port=41349)) * establish
* sales.us.example.com * 0
14-MAY-2012 15:38:44 * service_update * sales * 0
14-MAY-2012 15:38:44 * service_update * sales * 0
14-MAY-2012 15:48:45 * service_update * sales * 0
14-MAY-2012 15:48:45 * service_update * sales * 0
14-MAY-2012 15:50:57 *
(connect_data=(service_name=sales.us.example.com)(cid=(program=)
(host=sales-server)(user=jdoe)))
* (address=(protocol=tcp)(host=192.0.2.35)(port=41365)) * establish
* sales.us.example.com * 0
14-MAY-2012 15:51:26 * service_died * sales * 12537
14-MAY-2012 15:51:26 * service_died * sales * 12537
14-MAY-2012 15:52:06 *
(connect_data=(service_name=sales.us.example.com)
(cid=(program=)(host=sales-server)(user=jdoe)))
* (address=(protocol=tcp)(host=192.0.2.35)(port=41406)) * establish
* sales.us.example.com * 12514
TNS-12514: TNS:listener could not resolve SERVICE_NAME given in connect descriptor
--------------------------------
See Also:
Oracle Database Error Messages
for a complete listing of error messages
16.6.7.3 Listener Direct Hand-Off Information
The listener records direct hand-off events to
into the following fields:
Timestamp * Presentation * Handoff * Error Code
Properties of direct hand-off fields are as follows:
• Each field is delimited by an asterisk (
*
).
• A successful connection or command returns a code of zero.
• A failure produces a code that maps to an error message.
16-32 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
(page 16-33) shows a direct hand-off event in the log file.
Example 16-8 Listener Log Event for Direct Hand-Off
21-MAY-2012 10:54:55 * oracle.aurora.net.SALESHttp2 * handoff * 0
16.6.7.4 Listener Subscription for ONS Node Down Event Information
The listener subscribes to the Oracle Notification Service (ONS) node down event on startup if the ONS configuration file is available. This subscription enables the listener to remove the affected service when it receives node down event notification from
ONS. The listener uses asynchronous subscription for the event notification.
The following warning message is recorded to the listener log file on each
STATUS command if the subscription has not completed, such as the ONS daemon is not running on the host.
WARNING: Subscription for node down event still pending
The listener cannot receive the ONS event while subscription is pending. Other than that, no other listener functionality is affected.
16.6.7.5 Listener Oracle Clusterware Notification Information
If the required Oracle Clusterware (shown as CRS in the following log messages) libraries are installed and Oracle Clusterware is started on the host, then Oracle
Listener will notify Oracle Clusterware about its status during start and stop processes. After successful notification, listeners record the event in the log. No message is recorded if the notification fails.
Listener completed notification to CRS on start
Listener completed notification to CRS on stop
16.6.8 Analyzing Oracle Connection Manager Logs
Oracle Connection Manager generates four types of log files, one each for its listener, gateway, CMADMIN processes, and alerts. The alert log file is a chronological record of all critical errors. In addition to logging critical errors, the alert log captures information about instance startup and shutdown. It also records the value of all configuration parameters at the beginning and end of a session.
(page 16-34) and
Example 16-10 (page 16-34) are representative of the
CMADMIN and gateway log files. Table 16-16
(page 16-35) explains log entries. Each entry consists of a timestamp and an event. You can configure the cman.ora
file to log events for the following categories:
• Initialization and termination
• Memory operations
• Connection handling
• Process management
• Registration and load update
• Events related to CMADMIN wakeup queue
• Gateway timeouts
• Command processing
Troubleshooting Oracle Net Services 16-33
Logging Error Information for Oracle Net Services
• Events associated with connection control blocks
Use the
SET EVENT
command to specify which events to log.
(page 16-34) shows a typical CMADMIN log.
Example 16-9 CMADMIN Log File
-------------------------------
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:40)(EVENT=Parameter list)
(listener_address=(address=(protocol=tcp)(host=sales1)(port=1574)))
(aso_authentication_filter=OFF)
(connection_statistics=ON)
(log_directory=/home/user/network/admin/log)
(log_level=support)
(max_connections=256)
(idle_timeout=5)
(inbound_connect_timeout=0)
(session_timeout=20)
(outbound_connect_timeout=0)
(max_gateway_processes=1)
(min_gateway_processes=1)
(password=OFF)
(trace_directory=/home/user/network/admin/log)
(trace_level=off)
(trace_timestamp=OFF)
(trace_filelen=0)
(trace_fileno=0)
)
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:40)(EVENT=Shared Memory Size)
(BYTES=82524))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:40)(EVENT=GMON Attributes validated)
(Type=Information))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:40)(EVENT=NS Listen Successful)
((ADDRESS=(PROTOCOL=tcp)(HOST=usunnae16)(PORT=55878))))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:44)(EVENT=Received command)(CMD=verify password))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:44)(EVENT=Received command)
(CMD=version))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:44)(EVENT=Received command)
(CMD=show status))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:44)(EVENT=Failed to get procedure id))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:12)(EVENT=Received command)(CMD=verify password))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:15)(EVENT=Failed to get procedure id))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:29)(EVENT=Received command)(CMD=verify password))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:46)(EVENT=Failed to get procedure id))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:50)(EVENT=Received command)(CMD=verify password))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:50)(EVENT=Received command)
(CMD=probe monitor))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:50)(EVENT=Received command)
(CMD=shutdown normal))
-------------------------------
Example 16-10 (page 16-34) shows a typical gateway log file.
Example 16-10 Gateway Log File
-------------------------------
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=NS Initialised))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=Memory Allocated)
16-34 Oracle Database Net Services Administrator's Guide
Logging Error Information for Oracle Net Services
(BYTES=1024))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=NCR Initialised))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=Connected to Monitor))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=State Change from Empty to
Init))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=Memory Allocated)
(BYTES=251904))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=Memory Allocated)
(BYTES=2048))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=CCB Initialised))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=Started Listening))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:41)(EVENT=State Change from Init to
Ready))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:46:47)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:06)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:06)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:07)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:12)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:13)(EVENT=Idle Timeout)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:17)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:22)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:25)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:25)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:27)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:30)(EVENT=Idle Timeout)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:32)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:37)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:42)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:42)(EVENT=Ready)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:42)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:47)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:52)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:48:57)(EVENT=Housekeeping))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:02)(EVENT=Session Timeout)(CONN NO=0))
(LOG_RECORD=(TIMESTAMP=08-MAY-2012 08:49:02)(EVENT=Housekeeping))
-------------------------------
(page 16-35) shows the log file entries and their descriptions.
Table 16-16 CMADMIN and Gateway Log Entries
Log File
CMADMIN
CMADMIN
CMADMIN
CMADMIN
Gateway
Event Description
Failed to get procedure ID The CMCTL session connected to CMADMIN has disconnected.
GMON Attributes validated
Invalid connect data
Informational message. The parameters needed for CMADMIN to come up are specified correctly.
An unknown client is trying to connect to
CMADMIN. This is most likely a denial of service attack.
No connect data
Connected to Monitor
An unknown client is trying to connect to
CMADMIN. This is most likely a denial of service attack.
The gateway has connected to CMADMIN.
Troubleshooting Oracle Net Services 16-35
Tracing Error Information for Oracle Net Services
Table 16-16 (Cont.) CMADMIN and Gateway Log Entries
Log File
Gateway
Gateway
Gateway
Gateway
Gateway
Gateway
Event
Housekeeping
Idle Timeout
Out of connection control block (CCB)
Session Timeout
State change from Empty to Init
State change from Init to
Ready
Description
Informational message. Internal housekeeping for the gateway process is in order. The gateway process is properly connected to the
CMADMIN process.
The connection was disconnected because it was idle longer than the time specified in the cman.ora
file.
CMADMIN cannot process a connection request. There could be two reasons:
• Faulty load update between CMADMIN and listener.
• Someone is trying to connect to
CMADMIN directly (possibly a denial of service attack).
The connection was disconnected because it exceeded the session timeout specified in the cman.ora
file.
State change message from the gateway. After it reaches init state, the gateway begins some internal data initialization.
State change message from the gateway. After it reaches a ready state, the gateway begins accepting connections from the client.
16.7 Tracing Error Information for Oracle Net Services
Tracing produces a detailed sequence of statements that describe network events as they are run. Tracing an operation enables you to obtain more information about the internal operations of the components of Oracle Net Services than is provided in a log file. This information is output to files that can be evaluated to identify the events that led to an error.
Note:
Tracing uses a large amount of disk space and may have a significant impact upon system performance. Therefore, you should enable tracing only when necessary.
This section contains the following topics:
•
Understanding Oracle Net Services Trace File Names (page 16-37)
•
(page 16-37)
•
Setting Tracing During Control Utilities Runtime (page 16-46)
•
Evaluating Oracle Net Services Trace Files
(page 16-46)
16-36 Oracle Database Net Services Administrator's Guide
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•
Using the Trace Assistant to Examine Trace Files
(page 16-50)
16.7.1 Understanding Oracle Net Services Trace File Names
Each Oracle Net Services component produces its own trace file.
(page 16-37) provides the default trace file names and lists the components that generate the trace files.
Table 16-17 Trace Files Names
Trace File
instance-name_pid.trc
Component
Oracle Connection Manager listener instance-name_cmgw_pid.trc
Oracle Connection Manager CMGW process instance-name_cmadmin_pid.trc
Oracle Connection Manager CMADMIN process listener.trc
sqlnet.trc
svr_pid.trc
tnsping.trc
Listener
Client
Database server
TNSPING utility
16.7.2 Setting Tracing Parameters
Parameters that control tracing, including the type and amount of information trace, and the location where the files are stored, are set in the configuration file of each network component as described in
Table 16-18 Location of Trace Parameters
Configuration File
cman.ora
listener.ora
sqlnet.ora
Component
Oracle Connection Manager processes
Listener
Client
Database server
TNSPING utility
This section contains the following topics:
•
(page 16-38)
•
(page 16-38)
•
sqlnet.ora Trace Parameters (page 16-40)
•
Setting Tracing Parameters in Configuration Files
(page 16-44)
Troubleshooting Oracle Net Services 16-37
Tracing Error Information for Oracle Net Services
See Also:
Oracle Database Net Services Reference
for additional information about these parameters
16.7.2.1 cman.ora Trace Parameters
(page 16-38) describes the trace parameters settings for Oracle
Connection Manager that can be set in the cman.ora
file.
Table 16-19 cman.ora Trace Parameters
cman.ora Parameter
TRACE_DIRECTORY
TRACE_FILELEN
TRACE_FILENO
TRACE_LEVEL
TRACE_TIMESTAMP
Description
The destination directory for trace files.
By default, the directory is
ORACLE_HOME/network/trace
.
The size of the trace file in KB. When the size is reached, the trace information is written to the next file. The number of files is specified with the TRACE_FILENO parameter.
The number of trace files for tracing. When this parameter is set along with the TRACE_FILELEN parameter, trace files are used in a cyclical fashion. The first file is filled, then the second file, and so on. When the last file has been filled, the first file is reused, and so on.
The trace file names are distinguished from one another by their sequence number. For example, if this parameter is set to
3, then the Oracle Connection Manager trace files for the gateway processes would be named
instance-
name_cmgw1_pid.trc
,
instance-name_cmgw2_pid.trc
and
instance-name_cmgw3_pid.trc
.
In addition, trace events in the trace files are preceded by the sequence number of the file.
The level of detail the trace facility records for the listener. The trace level value can either be a value within the range of 0
(zero) to 16 where 0 is no tracing and 16 represents the maximum amount of tracing or one of the following values:
• off
(equivalent to 0) provides no tracing.
• user
(equivalent to 4) traces to identify user-induced error conditions.
• admin
(equivalent to 6) traces to identify installationspecific problems.
• support
(equivalent to 16) provides trace information for troubleshooting by Oracle Support Services.
The Oracle Connection Manager listener, gateway, and
CMADMIN processes create trace files on both Linux and
Microsoft Windows.
If the TRACING parameter is enabled, then a time stamp in the form of
dd-mon-yyyy hh:mi:ss:mil
is created for every trace event in the listener trace file.
16.7.2.2 listener.ora Trace Parameters
(page 16-39) describes the trace parameters settings for the listener that can be set in the listener.ora
file.
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Table 16-20 listener.ora Trace Parameters
listener.ora Parameter Oracle
Enterprise
Manager Cloud
Control/Oracle
Net Manager
Field
TRACE_LEVEL_listener
_name
Select a trace level/Trace
Level
TRACE_DIRECTORY_li
stener_name
TRACE_FILE_listener_n
ame
TRACE_FILEAGE_liste
ner_name
Trace File
You must set this parameter manually.
Description
The level of detail the trace facility records for the listener. The trace level value can either be a value within the range of 0 (zero) to 16 where 0 is no tracing and 16 represents the maximum amount of tracing or one of the following values:
• off
(equivalent to 0) provides no tracing.
• user
(equivalent to 4) traces to identify user-induced error conditions.
• admin
(equivalent to 6) traces to identify installation-specific problems.
• support
(equivalent to 16) provides trace information for troubleshooting by Oracle
Support Services.
The destination directory and file for the trace file. By default, the directory is
ORACLE_HOME/ network/trace
, and the file name is listener.trc
.
TRACE_FILEAGE_SER
VER
TRACE_FILELEN_listen
er_name
You must set this parameter manually.
You must set this parameter manually.
The maximum age of listener trace files in minutes. When the age limit is reached, the trace information is written to the next file. The number of files is specified with the
TRACE_FILENO_listener_name parameter.
Specifies the maximum age of server trace files in minutes. When the age limit is reached, the trace information is written to the next file. The number of files is specified with the
TRACE_FILENO_SERVER parameter.
The size of the listener trace files in KB. When the size is reached, the trace information is written to the next file. The number of files is specified with the
TRACE_FILENO_listener_name parameter
Troubleshooting Oracle Net Services 16-39
Tracing Error Information for Oracle Net Services
Table 16-20 (Cont.) listener.ora Trace Parameters
listener.ora Parameter Oracle
Enterprise
Manager Cloud
Control/Oracle
Net Manager
Field
TRACE_FILENO_listene
r_name
You must set this parameter manually.
TRACE_TIMESTAMP_l
istener_name
You must set this parameter manually.
Description
The number of trace files for listener tracing.
When this parameter is set along with the
TRACE_FILELEN_listener_name parameter, trace files are used in a cyclical fashion. The first file is filled, then the second file, and so on.
When the last file has been filled, the first file is re-used, and so on.
The trace file names are distinguished from one another by their sequence number. For example, if the default trace file of listener.trc
is used, and this parameter is set to 3, then the trace files would be named listener1.trc
, listener2.trc
and listener3.trc
.
In addition, trace events in the trace files are preceded by the sequence number of the file.
When this parameter is set with the
TRACE_FILEAGE_listener_name parameter, trace files are cycled based on the age of the trace file. The first file is used until the age limit is reached, then the second file is use, and so on. When the last file's age limit is reached, the first file is re-used, and so on.
When this parameter is set with both the
TRACE_FILELEN_listener_name and
TRACE_FILEAGE_listener_name parameters, trace files are cycled when either the size limit or the age limit is reached.
A time stamp in the form of
dd-mon-yyyy hh:mi:ss:mil
for every trace event in the listener trace file.
16.7.2.3 sqlnet.ora Trace Parameters
(page 16-40) describes the trace parameters settings that can be set in the sqlnet.ora
file.
Table 16-21 sqlnet.ora Trace Parameters
sqlnet.ora Parameter
TRACE_DIRECTORY_CLIEN
T
Oracle Net Manager
Field
Client Information:
Trace Directory
Description
The destination directory for the client trace output. By default, the client directory is
ORACLE_HOME/ network/trace
.
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Table 16-21 (Cont.) sqlnet.ora Trace Parameters
sqlnet.ora Parameter
TRACE_DIRECTORY_SERVE
R
Oracle Net Manager
Field
Server Information:
Trace Directory
TRACE_FILE_CLIENT
TRACE_FILE_SERVER
TRACE_FILEAGE_CLIENT
TRACE_FILEAGE_SERVER
TRACE_FILELEN_CLIENT
TRACE_FILELEN_SERVER
Client Information:
Trace File
Server Information:
Trace File
You must set this parameter manually.
You must set this parameter manually.
You must set this parameter manually.
You must set this parameter manually.
Description
The destination directory for the database server trace output. By default, the server directory is
ORACLE_HOME/network/trace
.
The name of the trace file for the client. By default, the trace file name is sqlnet.trc
.
The name of the trace file for the database server. By default the trace file name is svr_pid.trc
.
Specifies the maximum age of client trace files in minutes. When the age limit is reached, the trace information is written to the next file. The number of files is specified with the TRACE_FILENO_CLIENT parameter.
Specifies the maximum age of server trace files in minutes. When the age limit is reached, the trace information is written to the next file. The number of files is specified with the TRACE_FILENO_SERVER parameter.
The size of the client trace files in KB. When the size is reached, the trace information is written to the next file.
The number of files is specified with the
TRACE_FILENO_CLIENT parameter.
The size of the database server trace files in KB. When the size is reached, the trace information is written to the next file. The number of files is specified with the
TRACE_FILENO_SERVER parameter.
Troubleshooting Oracle Net Services 16-41
Tracing Error Information for Oracle Net Services
Table 16-21 (Cont.) sqlnet.ora Trace Parameters
sqlnet.ora Parameter
TRACE_FILENO_CLIENT
Oracle Net Manager
Field
You must set this parameter manually.
TRACE_FILENO_SERVER You must set this parameter manually.
Description
The number of trace files for client tracing. When this parameter is set along with the
TRACE_FILELEN_CLIENT parameter, trace files are used in a cyclical fashion. The first file is filled, then the second file, and so on. When the last file has been filled, the first file is re-used, and so on.
The trace file names are distinguished from one another by their sequence number. For example, if the default trace file of sqlnet.trc
is used, and this parameter is set to 3, then the trace files would be named sqlnet1_pid.trc
, sqlnet2_pid.trc
and sqlnet3_pid.trc
.
In addition, trace events in the trace files are preceded by the sequence number of the file.
When this parameter is set with the
TRACE_FILEAGE_CLIENT parameter, trace files are cycled based on the age of the trace file. The first file is used until the age limit is reached, then the second file is use, and so on. When the last file's age limit is reached, the first file is re-used, and so on.
When this parameter is set with both the
TRACE_FILELEN_CLIENT and
TRACE_FILEAGE_CLIENT parameters, trace files are cycled when either the size limit or age limit is reached.
The number of trace files for database server tracing.
When this parameter is set along with the
TRACE_FILELEN_SERVER parameter, trace files are used in a cyclical fashion. The first file is filled, then the second file, and so on. When the last file has been filled, the first file is re-used, and so on.
The trace file names are distinguished from one another by their sequence number. For example, if the default trace file of svr_pid.trc
is used, and this parameter is set to 3, then the trace files would be named svr1_pid.trc
, svr2_pid.trc
and svr3_pid.trc
.
In addition, trace events in the trace files are preceded by the sequence number of the file.
When this parameter is set with the
TRACE_FILEAGE_SERVER parameter, trace files are cycled based on the age of the trace file. The first file is used until the age limit is reached, then the second file is use, and so on. When the last file's age limit is reached, the first file is re-used, and so on.
When this parameter is set with both the
TRACE_FILELEN_SERVER and
TRACE_FILEAGE_SERVER parameters, trace files are cycled when either the size limit or age limit is reached.
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Table 16-21 (Cont.) sqlnet.ora Trace Parameters
sqlnet.ora Parameter
TRACE_LEVEL_CLIENT
Oracle Net Manager
Field
Client Information:
Trace Level
TRACE_LEVEL_SERVER
TRACE_TIMESTAMP_CLIEN
T
You must set this parameter manually.
TRACE_TIMESTAMP_SERVE
R
You must set this parameter manually.
TRACE_UNIQUE_CLIENT
Server Information:
Trace Level
Client Information:
Unique Trace File
Name
Description
The level of detail the trace facility records for the client.
The trace level value can either be a value within the range of 0 (zero) to 16 where 0 is no tracing and 16 represents the maximum amount of tracing or one of the following values:
• off
(equivalent to 0) provides no tracing.
• user
(equivalent to 4) traces to identify userinduced error conditions.
• admin
(equivalent to 6) traces to identify installation-specific problems.
• support
(equivalent to 16) provides trace information for troubleshooting by Oracle Support
Services.
The level of detail the trace facility records for the database server. The trace level value can either be a value within the range of 0 (zero) to 16 where 0 is no tracing and 16 represents the maximum amount of tracing or one of the following values:
• off
(equivalent to 0) provides no tracing.
• user
(equivalent to 4) traces to identify userinduced error conditions.
• admin
(equivalent to 6) traces to identify installation-specific problems.
• support
(equivalent to 16) provides trace information for troubleshooting by Oracle Support
Services.
A time stamp in the form of
dd-mon-yyyy hh:mi:ss:mil
for every trace event in the client trace file, sqlnet.trc
.
A time stamp in the form of
dd-mon-yyyy hh:mi:ss:mil
for every trace event in the client trace file, sqlnet.trc
.
When the value is set to on
, Oracle Net creates a unique file name for each trace session by appending a process identifier to the name of each trace file generated, and enabling several files to coexist. For example, trace files named sqlnetpid.trc
are created if default trace file name sqlnet.trc
is used.
When the value is set to off
, data from a new client trace session overwrites the existing file.
You can manually add the TNSPING utility tracing parameters described in
(page 16-44) to the sqlnet.ora
file. The TNSPING utility determines whether a service, such as a database or other TNS services on an Oracle Net network can be successfully reached.
Troubleshooting Oracle Net Services 16-43
Tracing Error Information for Oracle Net Services
Table 16-22 TNSPING Trace Parameters
sqlnet.ora Parameter
TNSPING.TRACE_DIREC
TORY
Description
The destination directory for TNSPING trace file, tnsping.trc
. By default, the directory is
ORACLE_HOME/ network/trace
.
TNSPING.TRACE_LEVEL
The level of detail the trace facility records for the TNSPING utility. The trace level value can either be a value within the range of 0 (zero) to 16 where 0 is no tracing and 16 represents the maximum amount of tracing or one of the following values:
• off
(equivalent to 0) provides no tracing.
• user
(equivalent to 4) traces to identify user-induced error conditions.
• admin
(equivalent to 6) traces to identify installationspecific problems.
• support
(equivalent to 16) provides trace information for troubleshooting by Oracle Support Services.
16.7.2.4 Setting Tracing Parameters in Configuration Files
Configure tracing parameters for the sqlnet.ora
file with Oracle Net Manager and listener.ora
file with either Oracle Enterprise Manager Cloud Control or Oracle
Net Manager. You must manually configure cman.ora
file tracing parameters.
This section contains the following topics:
•
Setting Tracing Parameters for sqlnet.ora File Using Oracle Net Manager
(page 16-44)
•
Setting Tracing Parameters for the Listener Using Oracle Enterprise Manager
•
Setting Tracing Parameters for the Listener Using Oracle Net Manager
(page 16-45)
16.7.2.4.1 Setting Tracing Parameters for sqlnet.ora File Using Oracle Net Manager
The following procedure describes how to set the tracing parameters for the sqlnet.ora
file using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
In the navigator pane, expand Profile under the Local heading.
From the list in the right pane, select General.
Click the Tracing tab.
Specify the settings.
Choose Save Network Configuration from the File menu.
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The name of the trace file for the client is sqlnet.trc
. The name of the trace file for the server is svr_pid.trc
.
16.7.2.4.2 Setting Tracing Parameters for the Listener Using Oracle Enterprise Manager Cloud
Control
The following procedure describes how to set the tracing parameters for the listener using Oracle Enterprise Manager Cloud Control:
1.
Access the Net Services Administration page in Oracle Enterprise Manager Cloud
Control.
See Also:
"
Using Oracle Enterprise Manager Cloud Control to Configure Oracle Net
(page 7-1)"
2.
3.
4.
5.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files.
Click Go to display the Listeners page.
Select a listener, and then click Edit to display the Edit Listeners page.
Click the Logging & Tracing tab.
6.
Specify the settings.
7.
Click OK.
The name of the trace file is listener.trc
.
16.7.2.4.3 Setting Tracing Parameters for the Listener Using Oracle Net Manager
The following procedure describes how to set the tracing parameters for the listener using Oracle Net Manager:
1.
Start Oracle Net Manager.
See Also:
"
Using Oracle Net Manager to Configure Oracle Net Services (page 7-2)"
2.
3.
4.
5.
6.
7.
In the navigator pane, expand Listeners from the Local heading.
Select a listener.
From the list in the right pane, select General.
Click the Logging and Tracing tab.
Specify the settings.
Choose Save Network Configuration from the File menu.
Troubleshooting Oracle Net Services 16-45
Tracing Error Information for Oracle Net Services
16.7.3 Setting Tracing During Control Utilities Runtime
You can set tracing during control utility runtime. Setting tracing with a control utility does not set parameters in the
*.ora
files. The setting is only valid for the session of the control utility:
• For the listener, use the
SET TRC_DIRECTORY
,
SET TRC_FILE
, and
SET
TRC_LEVEL
commands from the Listener Control utility.
• For Oracle Connection Manager, use the
SET TRACE_DIRECTORY
and
SET
TRACE_LEVEL
, and
SET TRACE_TIMESTAMP
commands from the Oracle
Connection Manager control utility.
16.7.4 Evaluating Oracle Net Services Trace Files
Trace files can help Oracle Support Services diagnose and troubleshoot network problems. This section explains how to perform basic analysis of trace files. It contains the following topics:
•
Flow of Data Packets Between Network Nodes
(page 16-46)
•
Oracle Net Data Packet Formats
(page 16-46)
•
Pertinent Oracle Net Trace Error Output (page 16-47)
16.7.4.1 Flow of Data Packets Between Network Nodes
Oracle Net performs its functions by sending and receiving data packets. You can view the actual contents of the Oracle Net packet in your trace file by specifying a trace level of support
. The order of the packet types sent and received help to determine how the connection was established.
16.7.4.2 Oracle Net Data Packet Formats
Each line in the trace file begins with a procedure followed by a message. Following each procedure is a line of hexadecimal data representing actual data. The actual data that flows inside the packet is sometimes viewable to the right of the hexadecimal data.
Each packet has a keyword that denotes the packet type. All packet types begin with the prefix " nsp
". This is helpful when reviewing trace files for specific packet information. The following keywords are used in a trace file:
• NSPTCN: Used with connect packet types.
• NSPTAC: Used with accept packet types.
• NSPTRF: Used with refuse packet types.
• NSPTRS: Used with resend packet types.
• NSPTDA: Used with data packet types.
• NSPCNL: Used with control packet types.
• NSPTMK: Used with marker packet types.
Example 16-11 (page 16-47) shows typical packet information. In the example, the
nscon
procedure sends an NSPTCN packet over the network.
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Example 16-11 Packet Information
nscon: entry nscon: doing connect handshake...
nscon: sending NSPTCN packet
nspsend: entry nspsend: plen=187, type=1 nspsend: 187 bytes to transport nspsend:packet dump nspsend:00 BB 00 00 01 00 00 00 |........| nspsend:01 33 01 2C 0C 01 08 00 |.3.,....| nspsend:7F FF 7F 08 00 00 00 01 |........| nspsend:00 99 00 22 00 00 08 00 |..."....| nspsend:01 01 28 44 45 53 43 52 |..(DESCR| nspsend:49 50 54 49 4F 4E 3D 28 |IPTION=(| nspsend:43 4F 4E 4E 45 43 54 5F |CONNECT_| nspsend:44 41 54 41 3D 28 53 49 |DATA=(SI| nspsend:44 3D 61 70 33 34 37 64 |D=ap347d| nspsend:62 31 29 28 43 49 44 3D |b1)(CID=| nspsend:28 50 52 4F 47 52 41 4D |(PROGRAM| nspsend:3D 29 28 48 4F 53 54 3D |=)(HOST=| nspsend:61 70 32 30 37 73 75 6E |sales-12| nspsend:29 28 55 53 45 52 3D 6D |)(USER=m| nspsend:77 61 72 72 65 6E 29 29 |scott))| nspsend:29 28 41 44 44 52 45 53 |)(ADDRES| nspsend:53 5F 4C 49 53 54 3D 28 |S_LIST=(| nspsend:41 44 44 52 45 53 53 3D |ADDRESS=| nspsend:28 50 52 4F 54 4F 43 4F |(PROTOCO| nspsend:4C 3D 74 63 70 29 28 48 |L=tcp)(H| nspsend:4F 53 54 3D 61 70 33 34 |OST=sale| nspsend:37 73 75 6E 29 28 50 4F |s-12)(PO| nspsend:52 54 3D 31 35 32 31 29 |RT=1521)| nspsend:29 29 29 00 00 00 00 00 |))).....| nspsend: normal exit nscon: exit (0)
16.7.4.3 Pertinent Oracle Net Trace Error Output
When there is a problem, the error code is logged in the trace file. Example 16-12
(page 16-47) illustrates typical trace file output for a failed SQL*Plus connection to a database server. The error message and error stack are shown in bold.
Example 16-12 Trace Example
[22-MAY-2012 13:34:07:687] nsprecv: entry
[22-MAY-2012 13:34:07:687] nsbal: entry
[22-MAY-2012 13:34:07:687] nsbgetfl: entry
[22-MAY-2012 13:34:07:687] nsbgetfl: normal exit
[22-MAY-2012 13:34:07:687] nsmal: entry
[22-MAY-2012 13:34:07:687] nsmal: 44 bytes at 0x132d90
[22-MAY-2012 13:34:07:687] nsmal: normal exit
[22-MAY-2012 13:34:07:687] nsbal: normal exit
[22-MAY-2012 13:34:07:687] nsprecv: reading from transport...
[22-MAY-2012 13:34:07:687] nttrd: entry
[22-MAY-2012 13:35:09:625] nttrd: exit
[22-MAY-2012 13:35:09:625] ntt2err: entry
[22-MAY-2012 13:35:09:625] ntt2err: Read unexpected EOF ERROR on 10
[22-MAY-2012 13:35:09:625] ntt2err: exit
[22-MAY-2012 13:35:09:625] nsprecv: transport read error
[22-MAY-2012 13:35:09:625] nsprecv: error exit
[22-MAY-2012 13:35:09:625] nserror: entry
[22-MAY-2012 13:35:09:625] nserror: nsres: id=0, op=68, ns=12537, ns2=12560;
Troubleshooting Oracle Net Services 16-47
Tracing Error Information for Oracle Net Services
nt[0]=507, nt[1]=0, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0
[22-MAY-2012 13:35:09:625] nscon: error exit
[22-MAY-2012 13:35:09:625] nsdo: nsctxrnk=0
[22-MAY-2012 13:35:09:625] nsdo: error exit
[22-MAY-2012 13:35:09:625] nscall: unexpected response
[22-MAY-2012 13:35:09:625] nsclose: entry
[22-MAY-2012 13:35:09:625] nstimarmed: entry
[22-MAY-2012 13:35:09:625] nstimarmed: no timer allocated
[22-MAY-2012 13:35:09:625] nstimarmed: normal exit
[22-MAY-2012 13:35:09:625] nsdo: entry
[22-MAY-2012 13:35:09:625] nsdo: cid=0, opcode=98, *bl=0, *what=0, uflgs=0x440, cflgs=0x2
[22-MAY-2012 13:35:09:625] nsdo: rank=64, nsctxrnk=0
[22-MAY-2012 13:35:09:625] nsdo: nsctx: state=1, flg=0x4201, mvd=0
[22-MAY-2012 13:35:09:625] nsbfr: entry
[22-MAY-2012 13:35:09:625] nsbaddfl: entry
[22-MAY-2012 13:35:09:625] nsbaddfl: normal exit
[22-MAY-2012 13:35:09:625] nsbfr: normal exit
[22-MAY-2012 13:35:09:625] nsbfr: entry
[22-MAY-2012 13:35:09:625] nsbaddfl: entry
[22-MAY-2012 13:35:09:625] nsbaddfl: normal exit
[22-MAY-2012 13:35:09:625] nsbfr: normal exit
[22-MAY-2012 13:35:09:625] nsdo: nsctxrnk=0
[22-MAY-2012 13:35:09:625] nsdo: normal exit
[22-MAY-2012 13:35:09:625] nsclose: closing transport
[22-MAY-2012 13:35:09:625] nttdisc: entry
[22-MAY-2012 13:35:09:625] nttdisc: Closed socket 10
[22-MAY-2012 13:35:09:625] nttdisc: exit
[22-MAY-2012 13:35:09:625] nsclose: global context check-out (from slot 0) complete
[22-MAY-2012 13:35:09:703] nsnadisc: entry
[22-MAY-2012 13:35:09:703] nadisc: entry
[22-MAY-2012 13:35:09:703] nacomtm: entry
[22-MAY-2012 13:35:09:703] nacompd: entry
[22-MAY-2012 13:35:09:703] nacompd: exit
[22-MAY-2012 13:35:09:703] nacompd: entry
[22-MAY-2012 13:35:09:703] nacompd: exit
[22-MAY-2012 13:35:09:703] nacomtm: exit
[22-MAY-2012 13:35:09:703] nas_dis: entry
[22-MAY-2012 13:35:09:703] nas_dis: exit
[22-MAY-2012 13:35:09:703] nau_dis: entry
[22-MAY-2012 13:35:09:703] nau_dis: exit
[22-MAY-2012 13:35:09:703] naeetrm: entry
[22-MAY-2012 13:35:09:703] naeetrm: exit
[22-MAY-2012 13:35:09:703] naectrm: entry
[22-MAY-2012 13:35:09:703] naectrm: exit
[22-MAY-2012 13:35:09:703] nagbltrm: entry
[22-MAY-2012 13:35:09:703] nau_gtm: entry
[22-MAY-2012 13:35:09:703] nau_gtm: exit
[22-MAY-2012 13:35:09:703] nagbltrm: exit
[22-MAY-2012 13:35:09:703] nadisc: exit
[22-MAY-2012 13:35:09:703] nsnadisc: normal exit
[22-MAY-2012 13:35:09:703] nsbfr: entry
[22-MAY-2012 13:35:09:703] nsbaddfl: entry
[22-MAY-2012 13:35:09:703] nsbaddfl: normal exit
[22-MAY-2012 13:35:09:703] nsbfr: normal exit
[22-MAY-2012 13:35:09:703] nsmfr: entry
[22-MAY-2012 13:35:09:703] nsmfr: 2256 bytes at 0x130508
[22-MAY-2012 13:35:09:703] nsmfr: normal exit
[22-MAY-2012 13:35:09:703] nsmfr: entry
[22-MAY-2012 13:35:09:703] nsmfr: 484 bytes at 0x1398a8
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[22-MAY-2012 13:35:09:703] nsmfr: normal exit
[22-MAY-2012 13:35:09:703] nsclose: normal exit
[22-MAY-2012 13:35:09:703] nscall: connecting...
[22-MAY-2012 13:35:09:703] nsclose: entry
[22-MAY-2012 13:35:09:703] nsclose: normal exit
[22-MAY-2012 13:35:09:703] nladget: entry
[22-MAY-2012 13:35:09:734] nladget: exit
[22-MAY-2012 13:35:09:734] nsmfr: entry
[22-MAY-2012 13:35:09:734] nsmfr: 144 bytes at 0x132cf8
[22-MAY-2012 13:35:09:734] nsmfr: normal exit
[22-MAY-2012 13:35:09:734] nsmfr: entry
[22-MAY-2012 13:35:09:734] nsmfr: 156 bytes at 0x138e70
[22-MAY-2012 13:35:09:734] nsmfr: normal exit
[22-MAY-2012 13:35:09:734] nladtrm: entry
[22-MAY-2012 13:35:09:734] nladtrm: exit
[22-MAY-2012 13:35:09:734] nscall: error exit
[22-MAY-2012 13:35:09:734] nioqper: error from nscall
[22-MAY-2012 13:35:09:734] nioqper: ns main err code: 12537
[22-MAY-2012 13:35:09:734] nioqper: ns (2) err code: 12560
[22-MAY-2012 13:35:09:734] nioqper: nt main err code: 507
[22-MAY-2012 13:35:09:734] nioqper: nt (2) err code: 0
[22-MAY-2012 13:35:09:734] nioqper: nt OS err code: 0
[22-MAY-2012 13:35:09:734] niomapnserror: entry
[22-MAY-2012 13:35:09:734] niqme: entry
[22-MAY-2012 13:35:09:734] niqme: reporting NS-12537 error as ORA-12537
[22-MAY-2012 13:35:09:734] niqme: exit
[22-MAY-2012 13:35:09:734] niomapnserror: returning error 12537
[22-MAY-2012 13:35:09:734] niomapnserror: exit
[22-MAY-2012 13:35:09:734] niotns: Couldn't connect, returning 12537
[22-MAY-2012 13:35:10:734] niotns: exit
[22-MAY-2012 13:35:10:734] nsbfrfl: entry
[22-MAY-2012 13:35:10:734] nsbrfr: entry
[22-MAY-2012 13:35:10:734] nsbrfr: nsbfs at 0x132d90, data at 0x132dc8.
[22-MAY-2012 13:35:10:734] nsbrfr: normal exit
[22-MAY-2012 13:35:10:734] nsbrfr: entry
[22-MAY-2012 13:35:10:734] nsbrfr: nsbfs at 0x1248d8, data at 0x132210.
[22-MAY-2012 13:35:10:734] nsbrfr: normal exit
[22-MAY-2012 13:35:10:734] nsbrfr: entry
[22-MAY-2012 13:35:10:734] nsbrfr: nsbfs at 0x12d820, data at 0x1319f0.
[22-MAY-2012 13:35:10:734] nsbrfr: normal exit
[22-MAY-2012 13:35:10:734] nsbfrfl: normal exit
[22-MAY-2012 13:35:10:734] nigtrm: Count in the NI global area is now 1
[22-MAY-2012 13:35:10:734] nigtrm: Count in the NL global area is now 1
Note:
In the error stack in the preceding example, an operating system error code is shown. Each operating system has its own error codes, refer to your system documentation for information about operating system error codes.
The most efficient way to evaluate error codes is to find the most recent nserror entry logged, as the session layer controls the connection. The most important error messages are the ones at the bottom of the file. They are the most recent errors and the source of the problem with the connection.
For information about the specific return codes, use the Oracle error tool oerr
, by entering the following at any command line: oerr tns
error_number
Troubleshooting Oracle Net Services 16-49
Tracing Error Information for Oracle Net Services
As an example, consider the following nserror
entry logged in the trace file shown in
[22-MAY-2012 13:35:09:625] nserror: nsres: id=0, op=68, ns=12537, ns2=
12560
; nt[0]=507, nt[1]=0, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0
In the preceding example, the main TNS error is 12537, and its secondary error is
12560. The protocol adapter error is 507. Using oerr
, you can find out more information about return codes 12537, 12560, and 507. User input is shown in bold in the following examples.
oerr tns 12537
12537, 00000, "TNS:connection closed"
// *Cause: "End of file" condition has been reached; partner has disconnected.
// *Action: None needed; this is an information message.
oerr tns 12560
12560, 00000, "TNS:protocol adapter error"
// *Cause: A generic protocol adapter error occurred.
// *Action: Check addresses used for proper protocol specification. Before
// reporting this error, look at the error stack and check for lower level
// transport errors. For further details, turn on tracing and reexecute the
// operation. Turn off tracing when the operation is complete.
oerr tns 507
00507, 00000, "Connection closed"
// *Cause: Normal "end of file" condition has been reached; partner has
// disconnected.
// *Action: None needed; this is an information message.
16.7.5 Using the Trace Assistant to Examine Trace Files
Oracle Net Services provides a tool called the Trace Assistant to help understand the information provided in trace files by converting existing lines of trace file text into a more readable paragraph. The Trace Assistant works only with level 16 (support)
Oracle Net Services trace files.
Note:
The Trace Assistant can only be used when the DIAG_ADR_ENABLED parameter is set to off
. See "
Understanding Automatic Diagnostic Repository
(page 16-1)".
This section contains the following topics:
•
(page 16-51)
•
•
Two-Task Common (TTC) Packet Examples (page 16-56)
•
(page 16-60)
•
(page 16-63)
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16.7.5.1 Trace Assistant Syntax
To run the Trace Assistant, enter the following command at any command line prompt: trcasst [
options
]
filename
The options are described in
Table 16-23 Trace Assistant Syntax
Option
-elevel
-la
-li ID
-otype
Description
Displays error information. After the
-e
, use
0
,
1
, or
2
error decoding level may follow:
•
0
or nothing translates the NS error numbers dumped from the nserror function plus lists all other errors
•
1
displays only the NS error translation from the nserror
function
•
2
displays error numbers without translation
If a connection ID exists in the NS connect packet, then the output displays the connection IDs. Connection IDs are displayed as hexadecimal, eight-byte IDs. A generated ID is created by Trace Assistant if the packet is not associated with any connection, that is, the connect packet is overwritten in the trace file. This can occur with cyclic trace files.
For each ID, the output lists the following:
• Socket ID, if the connection has one.
• Connect packet send or receive operation.
• Current setting of the
MULTIPLEX
attribute of the DISPATCHERS parameter in the initialization parameter file. When
MULTIPLEX
is set to
ON
,
• Session ID, if
MULTIPLEX
is set to
ON
.
• Connect data information.
Notes:
• Do not use this option with other options.
• The IDs generated by the Trace Assistant do not correlate with client/server trace files.
Displays the trace for a particular ID from the
-la
output
Note:
Only use this option with output from the
-la
option.
Displays the amount and type of information to be output. After the
-o
the following options can be used:
• c
to display summary connectivity information.
• d
to display detailed connectivity information.
• u
• t
to display detailed TTC information.
• q
to display SQL commands enhancing summary TTC information. Use this option with u
, such as
-ouq
.
Note:
As output for d
contains the same information as displayed for c
, do not submit both c
and d
. If you submit both, then only output d
is processed.
Troubleshooting Oracle Net Services 16-51
Tracing Error Information for Oracle Net Services
Table 16-23 (Cont.) Trace Assistant Syntax
Option
-s
Description
Displays the following statistical information:
• Total number of bytes sent and received.
• Maximum open cursors.
• Currently open cursors.
• Count and ratio of operations.
• Parsing and execution count for PL/SQL.
• Total calls sent and received.
• Total, average, and maximum number of bytes sent and received.
• Total number of transports and sessions present.
• Timestamp information, if any.
• Sequence numbers, if any.
If no options are provided, then the default is
-odt -e0 -s
, which provides detailed connectivity and TTC events, error level zero (0), and statistics in the trace file.
Example 16-13 (page 16-52) shows how the Trace Assistant converts the trace file
information into a more readable format using the
-e1
option.
Example 16-13 trcasst -e1 Output
*************************************************************************
* Trace Assistant *
************************************************************************* ntus2err: exit ntuscni: exit ntusconn: exit nserror: entry
-<ERROR>- nserror: nsres: id=0, op=65, ns=12541, ns2=12560; nt[0]=511, nt[1]=2, nt[2]=0
///////////////////////////////////////////////////////////////
Error found. Error Stack follows:
id:0
Operation code:65
NS Error 1:12541
NS Error 2:12560
NT Generic Error:511
Protocol Error:2
OS Error:0
NS & NT Errors Translation
12541, 00000 "TNS:no listener"
// *Cause: The connection request could not be completed because the listener
// is not running.
// *Action: Ensure that the supplied destination address matches one of
// the addresses used by the listener - compare the TNSNAMES.ORA entry with
// the appropriate LISTENER.ORA file (or TNSNAV.ORA if the connection is to
// go by way of an Interchange). Start the listener on the remote machine.
/
12560, 00000 "TNS:protocol adapter error"
// *Cause: A generic protocol adapter error occurred.
// *Action: Check addresses used for proper protocol specification. Before
// reporting this error, look at the error stack and check for lower level
// transport errors.For further details, turn on tracing and reexecute the
// operation. Turn off tracing when the operation is complete.
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/
00511, 00000 "No listener"
// *Cause: The connect request could not be completed because no application
// is listening on the address specified, or the application is unable to
// service the connect request in a sufficiently timely manner.
// *Action: Ensure that the supplied destination address matches one of
// the addresses used by the listener - compare the TNSNAMES.ORA entry with
// appropriate LISTENER.ORA file (or TNSNAV.ORA if the connection is to go
// by way of an Interchange. Start the listener on the remote machine.
/
///////////////////////////////////////////////////////////////
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
However, other errors may also exist within the trace file that were not logged from the nserror
function.
16.7.5.2 Packet Examples
Trace Assistant also enables you to view data packets from both the Oracle Net and
TTC communication layers. Trace Assistant offers two options to view these packets:
• Summary connectivity (using option
-oc
)
• Detailed connectivity (using option
-od
)
Example 16-14 (page 16-53) shows summary information from the
-oc
option.
Example 16-14 Summary Information from trcasst -oc Output
*************************************************************************
* Trace Assistant *
*************************************************************************
---> Send 198 bytes - Connect packet
Connect data length: 140
Connect Data:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(CID=(PROGRAM=)
(HOST=sales-server)(USER=joe))))
<--- Received 76 bytes - Redirect packet
Redirect data length: 66
Redirect Data:
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
---> Send 198 bytes - Connect packet
Connect data length: 140
Connect Data:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(CID=(PROGRAM=)
(HOST=sales-server)(USER=joe))))
<--- Received 32 bytes - Accept packet
Connect data length: 0
---> Send 153 bytes - Data packet
Native Services negotiation packet
<--- Received 127 bytes - Data packet
Native Services negotiation packet
Troubleshooting Oracle Net Services 16-53
Tracing Error Information for Oracle Net Services
---> Send 32 bytes - Data packet
<--- Received 140 bytes - Data packet
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
The packets being sent or received have a prefix of
---> Send nnn bytes
or
<---
Received nnn bytes
showing that this node is sending or receiving a packet of a certain type and with
nnn
number of bytes. This prefix enables you to determine if the node is the client or the database server. The connection request is always sent by the client, and received by the database server or listener.
Example 16-15 (page 16-54) shows detailed information from the
-od
option. The output shows all of the details sent along with the connect data in negotiating a connection.
Example 16-15 Detailed Information from trcasst -od Output
*************************************************************************
* Trace Assistant *
*************************************************************************
---> Send 241 bytes - Connect packet
Current NS version number is: 311.
Lowest NS version number can accommodate is: 300.
Global options for the connection:
can receive attention
no attention processing
Don't care
Maximum SDU size:8192
Maximum TDU size:32767
NT protocol characteristics:
Test for more data
Test operation
Full duplex I/O
Urgent data support
Generate SIGURG signal
Generate SIGPIPE signal
Generate SIGIO signal
Handoff connection to another
Line turnaround value :0
Connect data length :183
Connect data offset :58
Connect data maximum size :512
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Cross facility item 1: 0
Cross facility item 2: 0
Connection id : Ox000059F70000004C
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(SRVR=SHARED)(CID=(PROGRAM=)
(HOST=sales-server)(USER=joe))))
<--- Received 76 bytes - Redirect packet
Redirect data length: 66
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))
---> Send 241 bytes - Connect packet
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Current NS version number is: 311.
Lowest NS version number can accommodate is: 300.
Global options for the connection:
can receive attention
no attention processing
Don't care
Maximum SDU size:8192
Maximum TDU size:32767
NT protocol characteristics:
Test for more data
Test operation
Full duplex I/O
Urgent data support
Generate SIGURG signal
Generate SIGPIPE signal
Generate SIGIO signal
Handoff connection to another
Line turnaround value :0
Connect data length :183
Connect data offset :58
Connect data maximum size :512
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Cross facility item 1: 0
Cross facility item 2: 0
Connection id : Ox000059F70000007A
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(SRVR=SHARED)(CID=(PROGRAM=)
(HOST=sales-server)(USER=joe))))
<--- Received 32 bytes - Accept packet
Accepted NS version number is: 310.
Global options for the connection:
no attention processing
Don't care
Accepted maximum SDU size: 8192
Accepted maximum TDU size: 32767
Connect data length: 0
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Native Services wanted
NAU doing O3LOGON - DH key foldedin
---> Send 153 bytes - Data packet
Native Services negotiation packet version#: 150999040
Service data packet #0 for Supervisor has 3 subpackets
Subpacket #0: Version #150999040
Subpacket #1: 0000000000000000
Subpacket #2: DEADBEEF0003000000040004000100010002
Service data packet #1 for Authentication has 3 subpackets
Subpacket #0: Version #150999040
Subpacket #1: UB2: 57569
Subpacket #2: FCFF
Service data packet #2 for Encryption has 2 subpackets
Subpacket #0: Version #150999040
Subpacket #1: 000000000000000000
Service data packet #3 for Data Integrity has 2 subpackets
Subpacket #0: Version #150999040
Subpacket #1: 000000
Troubleshooting Oracle Net Services 16-55
Tracing Error Information for Oracle Net Services
<--- Received 127 bytes - Data packet
Native Services negotiation packet version#: 135290880
Service data packet #0 for Supervisor has 3 subpackets
Subpacket #0: Version #135290880
Subpacket #1: 0000
Subpacket #2: DEADBEEF00030000000200040001
Service data packet #1 for Authentication has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: FBFF
Service data packet #2 for Encryption has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: UB1: 0
Service data packet #3 for Data Integrity has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: UB1: 0
....
---> Send 11 bytes - Marker packet
One data byte.
Hex character sent over to the server: 2
<--- Received 11 bytes - Marker packet
One data byte.
Hex character sent over to the server: 2
<--- Received 155 bytes - Data packet
---> Send 25 bytes - Data packet
<--- Received 11 bytes - Data packet
---> Send 13 bytes - Data packet
<--- Received 11 bytes - Data packet
---> Send 10 bytes - Data packet
Data Packet flags:
End of file
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
16.7.5.3 Two-Task Common (TTC) Packet Examples
TTC handles requests such as open cursor, select rows, and update rows that are directed to the database server. All requests are answered by the database server. If you request to log on, then a response is returned from the database server that the request was completed.
Summary information for TTC from the
-ou
option is different from other displays in that it shows two packets on each line, rather than one. This is done to mirror the request/response pairings process by which TTC operates.
Output is displayed in the following format:
description TTC_message cursor_number SQL_statement bytes_sent bytes_received
Example 16-16 (page 16-57) shows all of the details sent along with the connect data
in negotiating a connection.
16-56 Oracle Database Net Services Administrator's Guide
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Example 16-16 trcasst -ou Output
*************************************************************************
* Trace Assistant *
*************************************************************************
Bytes Bytes
Sent Rcvd
Send operation(TTIPRO) 32 140
Send operation(TTIDTY) 33 22
Get the session key (OSESSKEY) 229 145
Generic authentication call (OAUTH) 368 1001
Send operation(TTIPFN) 44 144
Send operation(TTIPFN) 36 16
Parse a statement (OSQL) # 1 SELECT USER FROM ... 47 100
Fast upi calls to opial7 (OALL7) # 1 130 111
Fetch row (OFETCH) # 1 21 137
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 !Keep Parse BEGI... 156 145
Send operation(TTIPFN) 51 16
Parse a statement (OSQL) # 1 SELECT ATTRIBUTE,... 186 100
Fast upi calls to opial7 (OALL7) # 1 246 111
Fetch row (OFETCH) # 1 21 126
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Parse a statement (OSQL) # 1 SELECT CHAR_VALUE... 208 100
Fast upi calls to opial7 (OALL7) # 1 130 111
Fetch row (OFETCH) # 1 21 126
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse BEGI... 183 41
Send operation(TTIRXD) 20 111
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 Parse Fetch SELE... 165 278
Send operation(TTIPFN) 51 16
Parse a statement (OSQL) # 1 commit 31 100
Execute statement (OEXEC) # 1 number of rows: 1 25 100
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse BEGI... 183 41
Send operation(TTIRXD) 60 111
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse BEGI... 183 41
Send operation(TTIRXD) 20 111
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 Parse Fetch sele... 144 383
New v8 bundled call (OALL8) # 1 !Keep Fetch 121 315
Logoff off of Oracle (OLOGOFF) 13 11
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
Example 16-17 (page 16-57) shows detailed TTC information from the
-ot
option.
Example 16-17 Detailed TTC Information from trcasst -ot Output
*************************************************************************
* Trace Assistant
*
Troubleshooting Oracle Net Services 16-57
Tracing Error Information for Oracle Net Services
*************************************************************************
Set protocol (TTIPRO)
Operation 01 (con) Send protocol version=6
Originating platform: SVR4-be-8.1.0
Set protocol (TTIPRO)
Operation 01 (con) Receive protocol version=6
Destination platform: SVR4-be-8.1.0
Set datatypes (TTIDTY)
Set datatypes (TTIDTY)
Start of user function (TTIFUN)
(OSESSKEY)
Return opi parameter (TTIRPA)
Start of user function (TTIFUN)
(OAUTH)
Return opi parameter (TTIRPA)
Start of user function (TTIFUN)
session operations 71 (O71SESOPN) (switch session)
Return opi parameter (TTIRPA)
Start of user function (TTIFUN)
Get Oracle version/date string in new format (OVERSION)
Return opi parameter (TTIRPA)
Oracle Enterprise Edition Release 12.1.0.0.0
With the Partitioning option
JServer Release 12.1.0.0.0
Start of user function (TTIFUN)
session operations 71 (O71SESOPN) (switch session)
Return opi parameter (TTIRPA)
Start of user function (TTIFUN)
Open a cursor (OOPEN)
Return opi parameter (TTIRPA)
Cursor #: 1
Start of user function (TTIFUN)
Parse a statement (OSQL) Cursor # 1
SELECT USER FROM DUAL
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
Example 16-18 (page 16-59) shows detailed SQL information from the
-ouq
option.
On each line of the output, the first item displayed is the actual request made. The second item shows on what cursor that operation has been performed. The third item is either a listing of the SQL command or flag that is being answered. The number of bytes sent and received are displayed at the far right. A flag can be one of the following:
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• !PL/SQL = Not a PL/SQL request
• COM = Commit
• IOV = Get I/O Vector
• DEFN = Define
• EXEC = Execute
• FETCH = Fetch
• CAN = Cancel
• DESCSEL = Describe select
• DESCBND = Describe Bind
• BND = Bind
• PARSE = Parse
• EXACT = Exact
Example 16-18 Detailed SQL Information from trcasst -ouq Output
*************************************************************************
* Trace Assistant *
*************************************************************************
Bytes Bytes
Sent Rcvd
Send operation(TTIPRO) 32 140
Send operation(TTIDTY) 33 22
Get the session key (OSESSKEY) 229 145
Generic authentication call (OAUTH) 368 1001
Send operation(TTIPFN) 44 144
Send operation(TTIPFN) 36 16
Parse a statement (OSQL) # 1 47 100
SELECT USER FROM DUAL
Fast upi calls to opial7 (OALL7) # 1 130 111
Fetch row (OFETCH) # 1 21 137
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 !Keep Parse 156 145
BEGIN DBMS_OUTPUT.DISABLE; END;
Send operation(TTIPFN) 51 16
Parse a statement (OSQL) # 1 186 100
SELECT ATTRIBUTE,SCOPE,NUMERIC_VALUE,CHAR_VALUE,DA
TE_VALUE FROM SYSTEM.PRODUCT_PRIVS WHERE (UPPER('S
QL*Plus') LIKE UPPER(PRODUCT)) AND (UPPER(USER) LI
KE USERID)
Fast upi calls to opial7 (OALL7) # 1 246 111
Fetch row (OFETCH) # 1 21 126
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Parse a statement (OSQL) # 1 208 100
SELECT CHAR_VALUE FROM SYSTEM.PRODUCT_PRIVS WHERE
(UPPER('SQL*Plus') LIKE UPPER(PRODUCT)) AND ((UPPE
R(USER) LIKE USERID) OR (USERID = 'PUBLIC')) AND (
Troubleshooting Oracle Net Services 16-59
Tracing Error Information for Oracle Net Services
UPPER(ATTRIBUTE) = 'ROLES')
Fast upi calls to opial7 (OALL7) # 1 130 111
Fetch row (OFETCH) # 1 21 126
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse 183 41
BEGIN DBMS_APPLICATION_INFO.SET_MODULE(:1,NULL); E
ND;
Send operation(TTIRXD) 20 111
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 Parse Fetch 165 278
SELECT DECODE('A','A','1','2') FROM DUAL
Send operation(TTIPFN) 51 16
Parse a statement (OSQL) # 1 31 100
commit
Execute statement (OEXEC) # 1 number of rows: 1 25 100
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse 183 41
BEGIN DBMS_APPLICATION_INFO.SET_MODULE(:1,NULL); E
ND;
Send operation(TTIRXD) 60 111
Close cursor (OCLOSE) # 1 17 11
Send operation(TTIPFN) 36 16
Fast upi calls to opial7 (OALL7) # 1 !Keep Parse 183 41
BEGIN DBMS_APPLICATION_INFO.SET_MODULE(:1,NULL); E
ND;
Send operation(TTIRXD) 20 111
Close cursor (OCLOSE) # 1 17 11
New v8 bundled call (OALL8) # 0 Parse Fetch 144 383
select * from dept
New v8 bundled call (OALL8) # 1 !Keep Fetch 121 315
Logoff off of Oracle (OLOGOFF) 13 11
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
16.7.5.4 Connection Example
Example 16-19 (page 16-61) shows output from the
-la
option. The output shows the following information:
• Connect IDs received
• Socket ID on which this connection has come
• Operation
–
Receive
identifies the trace as a database server trace. In this example,
Receive
is the operation.
–
Send
identifies the trace as a client trace.
16-60 Oracle Database Net Services Administrator's Guide
Tracing Error Information for Oracle Net Services
•
MULTIPLEX
attribute of the DISPATCHERS parameter is set to
ON
• 32-bit session ID
• Connect data information received
Example 16-19 trcasst -la Output
*************************************************************************
* Trace Assistant *
*************************************************************************
Connection ID: 00000B270000000B
Socket Id: 15
Operation: Receive
Multiplex: ON
Session Id: 8362785DE4FC0B19E034080020F793E1
Connect Data:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVER=shared)
(SERVICE_NAME=sales.us.example.com)(CID=(PROGRAM=)(HOST=sales-server)
(USER=oracle))))
Connection ID: 00000B240000000B
Socket Id: 15
Operation: Receive
Multiplex: ON
Session Id: 8362785DE4FB0B19E034080020F793E1
Connect Data:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVER=shared)
(SERVICE_NAME=sales.us.example.com)(CID=(PROGRAM=)(HOST=sales-server)
(USER=oracle))))
Connection ID: 00000B1F00000008
Socket Id: 15
Operation: Receive
Multiplex: ON
Session Id: 8362785DE4F90B19E034080020F793E1
Connect Data:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVER=shared)
(SERVICE_NAME=sales.us.example.com)(CID=(PROGRAM=)(HOST=sales-server)
(USER=oracle))))
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
Example 16-20 (page 16-61) shows output for connection ID
00000B1F00000008 from the
-li 00000B1F00000008
option.
Example 16-20 trcasst -li Output
*************************************************************************
* Trace Assistant *
*************************************************************************
<--- Received 246 bytes - Connect packet
Current NS version number is: 310.
Lowest NS version number can accommodate is: 300.
Global options for the connection:
Can receive attention
No attention processing
Don't care
Troubleshooting Oracle Net Services 16-61
Tracing Error Information for Oracle Net Services
Maximum SDU size: 8192
Maximum TDU size: 32767
NT protocol characteristics:
Test for more data
Test operation
Full duplex I/O
Urgent data support
Generate SIGURG signal
Generate SIGPIPE signal
Generate SIGIO signal
Handoff connection to another
Line turnaround value: 0
Connect data length: 188
Connect data offset: 58
Connect data maximum size: 512
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Cross facility item 1: 0
Cross facility item 2: 0
Connection id: Ox00000B1F00000008
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=sales-server)(PORT=1521))
(CONNECT_DATA=(SERVER=shared)(SERVICE_NAME=sales.us.example.com)
(CID=(PROGRAM=)(HOST=sales-server)(USER=oracle))))
---> Send 114 bytes - Accept packet
Accepted NS version number is: 310.
Global options for the connection:
No attention processing
Don't care
Accepted maximum SDU size: 8192
Accepted maximum TDU size: 32767
Connect data length: 0
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Native Services wanted
NAU doing O3LOGON - DH key foldedin
Connection Time out: 1000
Tick Size: 100
Reconnect Data: (ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=34454))
Session Id: 8362785DE4F90B19E034080020F793E1
<--- Received 164 bytes - Data packet
Native Services negotiation packet version#: 135290880
Service data packet #0 for Supervisor has 3 subpackets
Subpacket #0: Version #135290880
Subpacket #1: 0000000000000000
Subpacket #2: DEADBEEF0003000000040004000100010002
Service data packet #1 for Authentication has 3 subpackets
Subpacket #0: Version #135290880
Subpacket #1: UB2: 57569
Subpacket #2: FCFF
Service data packet #2 for Encryption has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: 0000000000
Service data packet #3 for Data Integrity has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: 0000
---> Send 143 bytes - Data packet
Native Services negotiation packet version#: 135290880
Service data packet #0 for Supervisor has 3 subpackets
16-62 Oracle Database Net Services Administrator's Guide
Tracing Error Information for Oracle Net Services
Subpacket #0: Version #135290880
Subpacket #1: 0000
Subpacket #2: DEADBEEF00030000000200040001
Service data packet #1 for Authentication has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: FBFF
Service data packet #2 for Encryption has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: UB1: 0
Service data packet #3 for Data Integrity has 2 subpackets
Subpacket #0: Version #135290880
Subpacket #1: UB1: 0
<--- Received 48 bytes - Data packet
Set protocol (TTIPRO)
Operation 01 (con) Receive protocol version=6
Destination platform: SVR4-be-8.1.0
---> Send 156 bytes - Data packet
Set protocol (TTIPRO)
Operation 01 (con) Send protocol version=6
Originating platform: SVR4-be-8.1.0
<--- Received 49 bytes - Data packet
Set datatypes (TTIDTY)
---> Send 38 bytes - Data packet
Set datatypes (TTIDTY)
<--- Received 245 bytes - Data packet
Start of user function (TTIFUN)
Get the session key (OSESSKEY)
---> Send 161 bytes - Data packet
Return opi parameter (TTIRPA)
...
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
16.7.5.5 Statistics Example
The type of statistics gathered is approximately the number of TTC calls, packets, and bytes sent and received between the network partners.
shows typical trace file statistics from the
-s
option.
Example 16-21 trcasst -s Output
*************************************************************************
* Trace Assistant *
*************************************************************************
----------------------
Trace File Statistics:
----------------------
Total number of Sessions: 3
DATABASE:
Operation Count: 0 OPENS, 21 PARSES, 21 EXECUTES, 9 FETCHES
Parse Counts:
9 PL/SQL, 9 SELECT, 0 INSERT, 0 UPDATE, 0 DELETE,
0 LOCK, 3 TRANSACT, 0 DEFINE, 0 SECURE, 0 OTHER
Execute counts with SQL data:
9 PL/SQL, 0 SELECT, 0 INSERT, 0 UPDATE, 0 DELETE,
0 LOCK, 0 TRANSACT, 0 DEFINE, 0 SECURE, 0 OTHER
Packet Ratio: 6.142857142857143 packets sent per operation
Currently opened Cursors: 0
Maximum opened Cursors : 0
Troubleshooting Oracle Net Services 16-63
Contacting Oracle Support Services
ORACLE NET SERVICES:
Total Calls : 129 sent, 132 received, 83 oci
Total Bytes : 15796 sent, 13551 received
Average Bytes: 122 sent per packet, 102 received per packet
Maximum Bytes: 1018 sent, 384 received
Grand Total Packets: 129 sent, 132 received
*************************************************************************
* Trace Assistant has completed *
*************************************************************************
16.8 Contacting Oracle Support Services
Some messages recommend contacting Oracle Support Services to report a problem.
When you contact Oracle Support Services, have the following information available:
• The hardware, operating system, and release number of the operating system running Oracle Database.
• The complete release number of Oracle Database, such as release 12.2.0.1.0.
• All Oracle programs (with release numbers) in use when the error occurred, such as SQL*Plus release 12.2.0.1.0.
• If you encountered one or more error codes or messages, then the exact code numbers and message text, in the order in which they appeared.
• The problem severity, according to the following codes:
– 1: Program not usable. Critical effect on operations.
– 2: Program usable. Operations severely restricted.
– 3: Program usable with limited functions. Not critical to overall operations.
– 4: Problem circumvented by customer. Minimal effect, if any, on operations.
You will also be expected to provide the following:
• Your name
• The name of your organization
• Your Oracle Support ID number
• Your telephone number
16-64 Oracle Database Net Services Administrator's Guide
Glossary
access control list (ACL)
The group of access directives that you define. The directives grant levels of access to specific data for specific clients or groups of clients.
ACL
See
access control
A feature of Oracle Connection Manager that sets rules for denying or allowing certain clients to access designated servers.
address
See
ADR
See
Automatic Diagnostic Repository (ADR)
.
alias
An alternative name for a network object in a server. An alias stores the name of the object it is referencing. When a client requests a lookup of an alias, Oracle completes the lookup as if it is the referenced object.
application gateway
. An application gateway looks and acts like a real server from the client's point of view, and a real client from the server's point of view. An application gateway sits between the Internet and company's internal network, and provides middleman services (or proxy services) to users on either side.
ASCII character set
American Standard Code for Information Interchange character set, a convention for representing alphanumeric information using digital data. The collation sequence used by most computers with the exception of IBM and IBM-compatible computers.
Glossary-1
attribute
attribute authentication method
A security method that enables you to have high confidence in the identity of users, clients, and servers in distributed environments. Network authentication methods can also provide the benefit of single sign-on for users. The following authentication methods are supported:
• RADIUS (Remote Authentication Dial-In User Service)
• Kerberos
•
•
Microsoft Windows NT native authentication
Automatic Diagnostic Repository (ADR)
Automatic Diagnostic Repository (ADR) is a systemwide central repository for tracing and logging files. The repository is a file-based hierarchical data store for depositing diagnostic information.
cache
A piece of information that describes some aspect of a directory entry. An entry comprises a set of attributes, each of which belongs to an
attribute has both a type, which describes the kind of information in the attribute, and a value, which contains the actual data.
Memory that stores recently-accessed data so that subsequent requests to access the same data can be processed quickly.
CIDR
Classless Inter-Domain Routing (CIDR)
See
client
Classless Inter-Domain Routing. In CIDR notation, an IPv6 subnet is denoted by the subnet prefix and the size in bits of the prefix (in decimal), separated by the slash (
/
) character. For example,
2001:0db8:0000:0000::/64
denotes a subnet with addresses
2001:0db8:000:0000:0000:0000:0000:0000
through
2001:0db8:000:0000:FFFF:FFFF:FFFF:FFFF
. The CIDR notation includes support for IPv4 addresses. For example,
192.0.2.1/24
denotes the subnet with addresses
192.0.2.1
through
192.0.2.255
.
A user, software application, or computer that requests the services, data, or processing of another application or computer. The client is the user process. In a network environment, the client is the local user process and the server may be local or remote.
Glossary-2
connect data
client load balancing
Load balancing, whereby if more than one listener services a single database, a client can randomly choose between the listeners for its connect requests. This randomization enables all listeners to share the burden of servicing incoming connect requests.
client profile
The properties of a client, which may include the preferred order of
s, client and server
, the domain from which to request names, and
other client options.
client/server architecture
Software architecture based on a separation of processing between two CPUs. One
CPU acts as the client in the transaction, requesting and receiving services. The other acts as the server that processes the requests.
cman.ora file
An Oracle Connection Manager configuration file that specifies protocol addresses for incoming requests and administrative commands, as well as Oracle Connection
Manager parameters and
rules.
CMADMIN (Oracle Connection Manager Administration)
process that monitors the health of the listener and
Oracle Connection Manager gateway processes, shutting down and starting processes as needed. CMADMIN registers information about gateway processes with the listener and processes commands run with the Oracle Connection Manager Control utility.
CMGW (Oracle Connection Manager Gateway)
process that receives client connections screened and
forwarded by the listener located at the Oracle Connection Manager instance. The gateway process forwards the requests to the database server. In addition, it can multiplex or funnel multiple client connections through a single protocol connection.
connect data
A portion of the
that defines the destination database
or
Oracle system identifier (SID)
. In the following example, SERVICE_NAME defines a database service called sales.us.example.com
:
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521)
(CONNECT_DATA=
(SERVICE_NAME=sales.us.example.com)))
Glossary-3
connect descriptor
connect descriptor
A specially formatted description of the destination for a network connection. A connect descriptor contains destination service and network route information.
The destination service is indicated by using its
. The network route provides, at a minimum, the location of the listener through use of a network address.
connect identifier
or a name that maps to a connect descriptor. A connect identifier
, database
, or
Users initiate a connect request by passing a user name and password along with a connect identifier in a connect string for the service to which they want to connect:
CONNECT username@
connect_identifier
password
password
connect string
Information the user passes to a service to connect, such as user name and
CONNECT username@
net_service_name
connect-time failover
A client connect request is forwarded to a another listener if a listener is not responding. Connect-time failover is enabled by
, because the listener knows if an instance is running to attempt a connection.
connection
An interaction between two processes on a network. Connections are originated by an initiator (client) that requests a connection with a destination (server).
connection load balancing
The method for balancing the number of active connections for the same service across the instances and dispatchers. Connection load balancing enables listeners to make routing decisions based on how many connections there are for each dispatcher and the load on the nodes.
connection request
A notification sent by an initiator and received by a listener that indicates that the initiator wants to start a connection.
data packet
See
Glossary-4
directory naming
database link
A pointer that defines a one-way communication path from an Oracle database server to another database server. Public and private database links are a defined entries in a data dictionary table. Global database links are stored in an LDAP directory and can be accessed by all users on the network. To access public and private links, the user must be connected to the local database that contains the data dictionary entry.
A client connected to local database A can use a public or private link stored in database A to access information in remote database B. However, users connected to database B cannot use the same link to access data in database A. If local users on database B want to access data on database A, then a link must be defined and stored in the data dictionary of database B. Global links may be used between any clients and database on the network.
The following database links are supported:
•
in a specific schema of a database. Only the owner of a private database link can use it.
•
for a database. All users in the database can use it.
•
is a database link stored in the LDAP directory.
dedicated connection
A dedicated server with a database session.
dedicated server
A server process that is dedicated to one client connection. Contrast with
default domain
The
within which most client requests take place. It could be the domain where the client resides, or it could be a domain from which the client often requests network services. Default domain is also the client configuration parameter that determines what domain should be appended to unqualified network name requests.
A name request is unqualified if it does not have a "." character within it.
directory information tree (DIT)
A hierarchical tree-like structure in a
of the distinguished names
(DNs)
of the entries. This structure is specific to x500 and LDAP.
directory naming
that resolves a database service,
stored in a central directory server. A
provides central administration of directory naming objects, reducing the work
effort associated with adding or relocating services.
Glossary-5
directory server
directory server
A directory server that is accessed with
Lightweight Directory Access Protocol
. Support of LDAP-compliant directory servers provides a centralized method for managing and configuring a distributed Oracle network. The directory server can replace client-side and server-side localized tnsnames.ora
files.
dispatcher
A process that enables many clients to connect to the same server without the need for a dedicated server process for each client. A dispatcher handles and directs multiple
incoming network session requests to shared server processes. See also
distinguished name (DN)
Name of location in a
. The DN specifies where the entry resides in the
LDAP directory hierarchy, similar to the way a directory path specifies the exact location of a file.
distributed processing
Division of front-end and back-end processing to different computers. Oracle Network
Services support distributed processing by transparently connecting applications to remote databases.
domain
Any tree or subtree within the
most commonly refers to a group of computers whose host names share a common suffix, the domain name.
Domain Name System (DNS)
A system for naming computers and network services that is organized into a
s. DNS is used in TCP/IP networks to locate computers through
user-friendly names. DNS resolves a user-friendly name into an
, which is understood by computers.
For Oracle Network Services, DNS translates the host name in a TCP/IP address into an IP address.
DNS
See
.
enterprise role
An enterprise role is analogous to a regular database role, except that it spans authorization on multiple databases. An enterprise role is a category of roles that define privileges on a particular database. An enterprise role is created by the database administrator of a particular database. An enterprise role can be granted to or revoked from one or more enterprise users. The information for granting and revoking these roles is stored in the directory server.
Glossary-6
global database name
enterprise user
A user that has a unique identity across an enterprise. Enterprise users connect to individual databases through a schema. Enterprise users are assigned enterprise roles that determine their access privileges on databases.
entry
The building block of a directory server, it contains information about an object of interest to directory users.
external naming
that uses a third-party naming service, such as
.
external procedure
Function or procedure written in a third-generation language (3GL) that can be called from PL/SQL code. Only C is supported for external procedures.
failover
See
.
firewall support
See
FTP
File Transfer Protocol. A client/server protocol which allows a user on one computer to transfer files to and from another computer over a TCP/IP network.
global database link
A database link definition stored in an LDAP directory which can be accessed by all users on the network. This definition is the same as the one used for client connections to the database (name/connect-descriptor).
Global database links cannot include user or password clauses. They only work when the database initiating the link uses the identity of the existing client to establish the link.
global database name
The full name of the database which uniquely identifies it from any other database.
The global database name is of the form "
database_name.database_domain
," for example, sales.us.example.com
.
The database name portion, sales
, is a simple name to refer to the database. The database domain portion, us.example.com
, specifies the database domain in which the database is located, making the global database name unique. When possible,
Oracle recommends that your database domain mirror the network domain.
Glossary-7
Heterogeneous Services
The global database name is the default service name of the database, as specified by the SERVICE_NAMES parameter in the initialization parameter file.
Heterogeneous Services
An integrated component that provides the generic technology for accessing thirdparty systems from the Oracle database server. Heterogeneous Services enables you to:
• Use Oracle SQL to transparently access data stored in third-party systems as if the data resides within an Oracle server.
• Use Oracle procedure calls to transparently access third-party systems, services, or application programming interfaces (APIs), from the Oracle distributed environment.
hierarchical naming model
An infrastructure in which names are divided into multiple hierarchically-related domains.
host naming
that enables users in a TCP/IP environment to resolve names through their existing name resolution service. This name resolution service might be
,
Network Information Service (NIS)
, or simply a centrally-maintained set of
/etc/hosts
files. Host naming enables users to connect to an Oracle database server by simply providing the server computer's host name or host name alias. No client configuration is required to take advantage of this feature.
This method is recommended for simple TCP/IP environments.
HTTP identity management realm
A collection of identities, all of which are governed by the same administrative policies. In an enterprise, all employees having access to the intranet may belong to one realm, while all external users who access the public applications of the enterprise may belong to another realm. An identity management realm is represented in the directory by a specific entry with a special object class associated with it.
instance
Hypertext Transfer Protocol. A protocol that provides the language that enables web browsers and application web servers to communicate.
processes. When a database is started on a database server (regardless of the type of computer), Oracle allocates a memory area called the SGA and starts one or more
Oracle processes. The memory and processes of an instance efficiently manage the associated database's data and serve the database users. You can connect to any instance to access information within a cluster database.
Glossary-8
JDBC OCI Driver
instance name
A name of an Oracle database instance. The instance name is identified by the
INSTANCE_NAME parameter in the database initialization parameter file.
INSTANCE_NAME corresponds to the
Oracle system identifier (SID)
of the instance.
Clients can connect to a specific instance by specifying the INSTANCE_NAME parameter in the connect descriptor.
The instance name is included in the
IP address
Used to identify a node on a network. Each computer on the network is assigned a unique Internet Protocol (IP) address, which is made up of the network ID and a unique host ID. This address is typically represented in dotted-decimal notation, with the decimal value of each octet separated by a period, for example
192.0.2.22
.
IPC
Interprocess communication. A protocol used by client applications that resides on the same node as the listener to communicate with the database. IPC can provide a faster local connection than TCP/IP.
IPv4
Internet Protocol Version 4. IPv4 is the current standard for the IP protocol. IPv4 uses
32-bit (four-byte) addresses, which are typically represented in dotted-decimal notation. The decimal value of each octet is separated by a period, as in
192.0.2.22
.
IPv6
Internet Protocol Version 6. The protocol designed to replace
. In IPv6, an IP address is typically represented in eight fields of hexadecimal values separated by colons, as in
2001:0db8:0000:0000:0000:0000:1428:57AB
. In some cases, fields with
0
values can be compressed, as in
2001:DB8::1428:57AB
.
IP Version 4 (IPv4)
See
IP Version 6 (IPv6)
See
Java Database Connectivity (JDBC) Driver
A driver that provides Java applications and applets access to an Oracle database.
JDBC OCI Driver
A Type II driver for use with client/server Java applications. This driver requires an
Oracle client installation.
Glossary-9
JDBC Thin Driver
JDBC Thin Driver
A Type IV driver for Oracle JDBC applets and applications. Because it is written entirely in Java, this driver is platform-independent. It does not require any additional
Oracle software on the client side. The Thin driver communicates with the server using
, a protocol developed by Oracle to access the database server.
keyword-value pair
The combination of a keyword and a value, used as the standard unit of information in connect descriptors and many configuration files. Keyword-value pairs may be nested, that is, a keyword may have another keyword-value pair as its value.
latency
Networking round-trip time.
LDAP Data Interchange Format (LDIF)
LDAP Data Interchange Format is the set of standards for formatting an input file for any of the LDAP command line utilities.
ldap.ora file
A file created by Oracle Internet Directory Configuration Assistant or Oracle Net
Configuration Assistant that contains the following directory server access information:
• Type of directory server.
• Location of the directory server.
• Default Oracle Context that the client or server use to look up or configure connect identifiers for connections to database services.
When created with Oracle Internet Directory Configuration Assistant, the ldap.ora
file is located in the
ORACLE_HOME/ldap/admin
directory. When created with Oracle
Net Configuration Assistant, the ldap.ora
file is located in the
ORACLE_HOME/ network/admin
directory.
LDIF
LDAP Data Interchange Format (LDIF)
Lightweight Directory Access Protocol (LDAP)
A standard, extensible directory access protocol. It is a common language that LDAP clients and servers use to communicate. The framework of design conventions
Glossary-10
local naming
link qualifier
A qualifier appended to a global database link to provide alternate settings for the database user name and password credentials. For example, a link qualifier of fieldrep
can be appended to a global database link of sales.us.example.com
.
SQL> SELECT * FROM [email protected]@fieldrep
listener
See
.
Listener Control utility
A utility included with Oracle Net Services to control listener functions, such as starting, stopping, and getting the status of the listener.
listener.ora file
A configuration file for Oracle Net Listener that identifies the following:
• Unique name
• Protocol addresses that it is accepting connection requests on
• Services it is listening for
The listener.ora
file typically resides in the
ORACLE_HOME/network/admin directory.
Oracle Database does not require identification of the database service because of
. However, static service configuration is required if you plan to use Oracle Enterprise Manager Cloud Control.
Listener Registration (LREG)
, LREG registers instance information with the listener.
LREG is an instance background process of each database instance that is configured in the database initialization parameter file.
load balancing
A feature by which client connections are distributed evenly among multiple listeners, dispatchers, instances, and nodes so that no single component is overloaded.
Oracle Network Services support
.
local naming
that locates network addresses by using information configured and stored on each individual client's
. Local naming is most appropriate for simple distributed networks with a small number of services that change infrequently.
Glossary-11
location transparency
location transparency
A distributed database characteristic that enables applications to access data tables without knowing where they reside. All data tables appear to be in a single database, and the system determines the actual data location based on the table name. The user can reference data on multiple nodes in a single statement, and the system automatically and transparently routes (parts of) SQL statements to remote nodes, if needed. The data can move among nodes with no impact on the user or application.
logging
A feature in which errors, service activity, and statistics are written to a log file. The log file provides additional information for an administrator when the error message on the screen is inadequate to understand the failure. The log file, by way of the error stack, shows the state of the software at various layers.
loopback test
A connection from the server back to itself. Performing a successful loopback verifies that Oracle Net is functioning on the database server.
map
Files used by the
Network Information Service (NIS)
ypserv
program to handle name requests.
Microsoft Active Directory
An LDAP-compliant directory server included with the Microsoft Windows Server. It stores information about objects on the network, and makes this information available to users and network administrators. Active Directory also provides access to resources on the network using a single logon process.
Active Directory can be configured as a directory naming method to store service information that clients can access.
Microsoft Windows NT native authentication
that enables a client to have single login access to a
Microsoft Windows NT server and a database running on the server.
Named Pipes protocol
A high-level interface protocol providing interprocess communications between clients and servers using distributed applications.
naming context
A subtree that resides entirely on one directory server. It is a contiguous subtree, that is, it must begin at an entry that serves as the top of the subtree, and extend downward to either leaf entries or references to subordinate naming contexts. It can
range in size from a single entry to the entire
directory information tree (DIT)
Glossary-12
network administrator
can be created under a naming context.
naming method
The resolution method used by a client application to resolve a
to a
when attempting to connect to a database service. Oracle Net provides four naming methods:
•
•
• Easy Connect naming
•
network service alias
object in a directory server. A directory
server stores network service aliases for any defined
database service. A network service alias entry does not have connect descriptor information. Instead, it only references the location of the object for which it is an alias.
When a client requests a directory lookup of a network service alias, the directory determines that the entry is a network service alias and completes the lookup as if the alias was actually the entry it is referencing.
network service name
A simple name for a service that resolves to a
. Users initiate a connect request by passing a user name and password, along with a network service name in a connect string, for the service to which they want to connect:
CONNECT username@net_service_name
Depending on your needs, network service names can be stored in a variety of places, including:
• Local configuration file, tnsnames.ora
, on each client
• Directory server
• External naming service, such as
Network Information Service (NIS)
network
A group of two or more computers linked together through hardware and software to allow the sharing of data and peripherals.
network administrator
The person who performs network management tasks such as installing, configuring, and testing network components. The administrator typically maintains the configuration files, connect descriptors and service names, aliases, and public and global database links.
Glossary-13
network character set
network character set
As defined by Oracle, the set of characters acceptable for use as values in keywordvalue pairs, that is, in connect descriptors and configuration files. The set includes alphanumeric uppercase and lowercase, and some special characters.
Network Information Service (NIS)
The client/server protocol for distributing system configuration data such as user and host names between computers on a network. This service was formerly known as
"Sun Microsystems Yellow Pages ( yp
)."
Network Interface (NI)
A network layer that provides a generic interface for Oracle clients, servers, or external processes to access Oracle Net functions. The NI layer handles the "break" and "reset" requests for a connection.
network listener
See
network object
Any service that can be directly addressed on a network; for example, a listener.
network protocol
See
.
Network Program Interface (NPI)
An interface for server-to-server interactions that performs all of the functions that the
does for clients, allowing a coordinating server to
construct SQL requests for additional servers.
Network Session (NS)
used in typical Oracle Net connections to establish and maintain the connection between a client application and a database server.
NIS
See
Network Information Service (NIS)
node
A computer or terminal that is part of a network.
Glossary-14
Oracle Connection Manager
object class
In a directory server, a named group of attributes. When you want to assign attributes to an entry, you do so by assigning that entry the object classes that hold those attributes.
All objects associated with the same object class share the attributes of that object class.
OCI
OPI
Oracle Program Interface (OPI)
Open Systems Interconnection (OSI)
A model of network architecture developed by International Organization for
Standardization (ISO) as a framework for international standards in heterogeneous computer network architecture.
The OSI architecture is divided into seven layers as follows, from lowest to highest:
1. Physical layer
2. Data link layer
3. Network layer
4. Transport layer
5. Session layer
6. Presentation layer
7. Application layer
Each layer uses the layer immediately preceding it and provides a service to the layer following it.
Oracle Advanced Security
An Oracle product that provides Transparent Data Encryption (TDE) and data redaction.
Oracle Call Interface (OCI)
An application programming interface (API) that enables creation of applications that use the native procedures or function calls of a third-generation language to access an
Oracle database server and control all phases of SQL statement execution. OCI supports the data types, calling conventions, syntax, and semantics of a number of third-generation languages including C, C++, COBOL and FORTRAN.
Oracle Connection Manager
A router through which a client connection request may be sent either to its next hop or directly to the database server. Clients who route their connection requests through
Glossary-15
Oracle Connection Manager Control utility
Oracle Connection Manager can then take advantage of the
,
features configured on that Oracle Connection
Manager.
Oracle Connection Manager Control utility
A utility included with Oracle Network Services to control various functions, such as starting, stopping, and getting the status of Oracle Connection Manager.
Oracle Context
An entry in an LDAP-compliant Internet directory called cn=OracleContext
, under which all Oracle software relevant information is kept, including entries for Oracle Net
Services directory naming and checksumming security. There may be one or more than one Oracle Context in a directory. An Oracle Context entry can be associated with a directory naming context.
automatically creates an Oracle Context entry at the root of the
directory information tree (DIT)
structure. This root Oracle Context has a
dn:cn=OracleContext
.
Oracle Enterprise Manager Cloud Control
A separate Oracle product that combines a graphical console, agents, common services, and tools to provide an integrated and comprehensive systems management platform for managing Oracle products.
Oracle Identity Management
An infrastructure enabling deployments to manage centrally and securely all enterprise identities and their access to various applications in the enterprise.
Oracle Internet Directory
A directory server implemented as an application on the Oracle database. It enables retrieval of information about dispersed users and network resources. It combines
Lightweight Directory Access Protocol (LDAP)
Version 3, the open Internet standard directory server access protocol, with the high performance, scalability, robustness, and availability of the Oracle database.
Oracle Net
Communication software that enables a network session from a client application to an Oracle database server. After a network session is established, Oracle Net acts as a data courier for the client application and the database server. It is responsible for establishing and maintaining the connection between the client application and database server, as well as exchanging messages between them. Oracle Net is able to perform these jobs because it is located on each computer in the network.
Oracle Net Configuration Assistant
A postinstallation tool that configures basic network components after installation, including:
• Listener names and protocol addresses
Glossary-16
Oracle Net Services
•
Naming methods the client uses to resolve
• Net service names in a tnsnames.ora
file
• Directory server usage
Oracle Net Firewall Proxy
Product offered by some firewall vendors that supplies
functionality.
Oracle Net foundation layer
A networking communication layer that is responsible for establishing and maintaining the connection between the client application and server, as well as exchanging messages between them.
Oracle Net Listener
A process that resides on the server whose responsibility is to listen for incoming client connection requests and manage the traffic to the server.
When a client requests a network session with a database server, a listener receives the actual request. If the client information matches the listener information, then the listener grants a connection to the database server.
Oracle Net Manager
A tool that combines configuration capabilities with component control to provide an integrated environment for configuring and managing Oracle Net Services.
Use Oracle Net Manager to configure the following network components:
• Naming
Define
network location and identification of a service. Oracle Net Manager supports configuration of connect descriptors in a local tnsnames.ora
file or directory server.
• Naming Methods
Configure the different methods in which connect identifiers are resolved into connect descriptors.
• Listeners
Create and configure listeners to receive client connections.
Oracle Net Services
A suite of networking components that provide enterprise-wide connectivity solutions in distributed, heterogeneous computing environments. Oracle Net Services is comprised of
Glossary-17
Oracle Program Interface (OPI)
Oracle Program Interface (OPI)
A networking layer responsible for responding to each of the possible messages sent
. For example, an OCI request to fetch 25 rows would
have an OPI response to return the 25 rows after they have been fetched.
Oracle protocol support
A software layer responsible for mapping
Transparent Network Substrate (TNS)
functionality to industry-standard protocols used in the client/server connection.
Oracle Real Application Clusters (Oracle RAC)
An architecture that allows multiple instances to access a shared database of datafiles.
Oracle RAC is also a software component that provides the necessary cluster database scripts, initialization files, and datafiles needed for Oracle Enterprise Edition and
Oracle RAC.
Oracle Rdb
A database for Digital 64-bit platforms. Because Oracle Rdb has its own listener, the client interacts with Rdb in the same manner as it does with an Oracle database.
Oracle schema
A set of rules that determine what can be stored in a
. Oracle has its own schema that is applied to many types of Oracle entries, including Oracle Net
Services entries. The Oracle schema for Oracle Net Services' entries includes the attributes the entries may contain.
Oracle system identifier (SID)
A name that identifies a specific instance of an Oracle database. For any database, there is at least one instance referencing the database.
Oracle XML DB
A high-performance XML storage and retrieval technology provided with Oracle database server. It is based on the W3C XML data model.
ORACLE_HOME
An alternate name for the top directory in the Oracle directory hierarchy on some directory-based operating systems.
OSI
See
Open Systems Interconnection (OSI)
.
packet
A block of information sent over the network each time a connection or data transfer is requested. The information contained in packets depends on the type of packet:
Glossary-18
protocol stack connect, accept, redirect, data, and so on. Packet information can be useful in troubleshooting.
PMON process
A process monitor database process that performs process recovery when a client process fails. PMON is responsible for cleaning up the cache and freeing resources that the process was using. PMON also checks on dispatcher and server processes and restarts them if they have failed.
presentation layer
A networking communication layer that manages the representation of information that application layer entities either communicate or reference in their communication.
is an example of presentation layer.
private database link
A database link created by one user for his or her exclusive use.
.
profile
A collection of parameters that specifies preferences for enabling and configuring
Oracle Net Services features on the client or server. A profile is stored and implemented through the sqlnet.ora
file.
protocol
A set of rules that defines how data is transported across the network.
protocol address
An address that identifies the network address of a network object.
When a connection is made, the client and the receiver of the request, such as the
, are configured with identical protocol
addresses. The client uses this address to send the connection request to a particular network object location, and the recipient listens for requests on this address. It is important to install the same protocols for the client and the connection recipient, and to configure the same addresses.
protocol conversion
A feature of Oracle Connection Manager that enables a client and server with different networking protocols to communicate with each other.
protocol stack
Glossary-19
proxy server
proxy server
A server that substitutes for the real server, forwarding client connection requests to the real server or to other proxy servers. Proxy servers provide access control, data and system security, monitoring, and caching.
public database link
A database link created by a DBA on a local database that is accessible to all users of that database.
.
realm Oracle Context
An Oracle Context contained in each
. It stores the following information:
• User naming policy of the identity management realm, that is, how users are named and located.
• Mandatory authentication attributes.
• Location of groups in the identity management realm.
• Privilege assignments for the identity management realm, such as, who has privileges to add more users to the realm.
• Application specific data for that realm including authorizations.
RDBMS
Relational Database Management System.
RDN
See
relative distinguished name (RDN)
.
relative distinguished name (RDN)
The local, most granular level entry name. It has no other qualifying entry names that would serve to address the entry uniquely. It is a fully-qualified X.500 name. For example, cn=sales,dc=us,dc=example,dc=com
, cn=sales
is a RDN.
root Oracle Context
infrastructure, the root Oracle Context is an entry
in Oracle Net Services containing a pointer to the default
in the infrastructure. It also contains information about how to locate an identity management realm given a simple name of the realm.
RPC
Remote Procedure Call.
Glossary-20
service registration
SDP
Sockets Direct Protocol (SDP).
Secure Sockets Layer (SSL)
An industry standard protocol designed by Netscape Communications Corporation for securing network connections. SSL provides authentication, encryption, and data integrity using public key infrastructure (PKI).
server parameter file
A binary file containing initialization parameter settings that is maintained on the
Oracle Database host. You cannot manually edit this file with a text editor. A server parameter file is initially built from a text initialization parameter file by means of the
CREATE SPFILE
statement or created directly.
server process
Database process that handles a client request on behalf of a database.
service
A program that responds to requests from various clients or performs some operation.
The database is a service that stores and retrieves data for clients.
service handler
A process that acts as a connection point from the listener to the database server. A
or
service name
A logical representation of a database, which is the way a database is presented to
clients. The service name is a string that is the
, that is, a name comprised of the database name and domain name, entered during installation or database creation. If you are not sure what the global database name is, then you can obtain it from the value of the SERVICE_NAMES parameter in the initialization parameter file.
The service name is included in the
service registration
A feature by which the
process automatically registers information with a
. Because this information is registered with the listener, the listener.ora
file does not need to be configured with this static information.
Service registration provides the listener with information about:
• Service names for each running instance of the database.
• Instance names of the database.
Glossary-21
session data unit (SDU)
•
) available for each instance.
These enable the listener to direct a client request appropriately.
• Dispatcher, instance, and node load information.
This load information enables the listener to determine which dispatcher can best handle a client connection request. If all dispatchers are blocked, then the listener can spawn a dedicated server for the connection.
session data unit (SDU)
A buffer that Oracle Net uses to place data before transmitting it across the network.
Oracle Net sends the data in the buffer either when requested or when it is full.
session layer
A network layer that provides the services needed by the
entities that enable them to organize and synchronize their dialogue and manage their data exchange. This layer establishes, manages, and terminates network sessions between
the client and server. An example of a session layer is
session multiplexing
Combining multiple sessions for transmission over a single network connection to conserve the operating system's resources.
shared server
A database server that is configured to allow many client processes to share very few server processes, so the number of users that can be supported is increased. With
shared server configuration, many client processes connect to a
dispatcher directs multiple incoming network session requests to a common queue.
An idle shared server process from a shared pool of server processes picks up a request from the queue. Thus, a small pool of server processes can serve a large
number of clients. Contrast with
.
shared server process
A process type used with
configuration.
SID
See
Oracle system identifier (SID)
.
Single Client Access Name (SCAN)
It is a feature used in Oracle Real Application Clusters environments that provides a single name for clients to access any Oracle Database running in a cluster.
single sign-on
The ability of a user to log in to different servers using a single password. This permits the user to authenticate to all servers the user is authorized to access.
Glossary-22
tnsnames.ora file
sqlnet.ora file
A configuration file for the client or server that specifies:
• Client domain to append to unqualified service names or network service names.
• Order of naming methods the client should use when resolving a name.
• Logging and tracing features to use.
• Route of connections.
• External naming parameters.
• Security parameters.
The sqlnet.ora
file typically resides in the
ORACLE_HOME/network/admin directory.
SSL
.
System Global Area (SGA)
A group of shared memory structures that contain data and control information for an
TCP/IP
Transmission Control Protocol/Internet Protocol. The standard communication protocol used for client/server communication over a network.
TCP/IP with SSL protocol
A protocol that enables an Oracle application on a client to communicate with remote
Oracle databases through the
tick
The amount of time it takes for a message to be sent and processed from the client to the server or from the server to the client.
TNS
Transparent Network Substrate (TNS)
.
tnsnames.ora file
A configuration file that maps
method. The tnsnames.ora
file typically resides in the
ORACLE_HOME/network/admin
directory.
Glossary-23
tracing
tracing
A utility that writes detailed information about an operation to an output file. The trace utility produces a detailed sequence of statements that describe the events of an operation as they are run. Administrators use the trace utility for diagnosing an abnormal condition. It is not normally turned on.
Transparent Application Failover (TAF)
A runtime failover for high-availability environments, such as Oracle RAC and Oracle
Fail Safe, that refers to the failover and re-establishment of application-to-service connections. It enables client applications to automatically reconnect to the database if the connection fails, and, optionally, resume a
SELECT
statement that was in progress.
This reconnect happens automatically from within the Oracle Call Interface (OCI) library.
Transparent Network Substrate (TNS)
A foundation technology, built into the
that works with any standard network transport protocol.
transport
A networking layer that maintains end-to-end reliability through data flow control and error recovery methods. The
for the transport layer.
TTC
See
Two-Task Common (TTC)
type that is used in a typical Oracle Net connection to provide character set and data type conversion between different character sets or formats on the client and server.
UPI
User Program Interface.
virtual circuit
A piece of shared memory used by the
for client database connection requests and replies. The dispatcher places a virtual circuit on a common queue when a request arrives. An idle shared server picks up the virtual circuit from the common queue, services the request, and relinquishes the virtual circuit before attempting to retrieve another virtual circuit from the common queue.
Glossary-24
WebDAV protocol
WebDAV protocol
World Wide Web Distributed Authoring and Versioning. A protocol with a set of extensions to the
which allows users to manage files on remote web servers.
Glossary-25
Symbols
1521 port if not using,
A
access control lists (ACLs) described,
access control to database with Oracle Connection Manager,
,
with sqlnet.ora parameters,
ACTION_LIST networking parameter,
ADAPTERS utility,
Address List Options dialog box,
ADR
automatic diagnostic repository
ADR_BASE log parameter,
ADR_BASE_listener_name log parameter,
ADRCI,
application web servers,
application Web servers, architecture
Oracle Connection Manager, attributes
audit trail
described,
script for using information,
automatic diagnostic repository,
B
Bequeath protocol,
BEQUEATH_DETACH networking parameter,
buffer flushing, described,
C
centralized naming
Index
centralized naming (continued)
establishing a connection with,
Check TCP/IP client access rights option in Oracle Net
Manager,
client configuration connect-time failover, default domains,
load balancing requests among listeners,
log files,
Oracle Connection Manager address,
Oracle Rdb connections,
shared server,
Transparent Application Failover (TAF),
client connections
client load balancing
Client Registration ID field in Oracle Net Manager,
client-server connections routing,
Clients allowed to access field in Oracle Net Manager,
Clients excluded from access field in Oracle Net
Manager,
CMADMIN (Connection Manager Administration),
CMAN DISPATCHERS parameter, cman.ora file
log parameters
ADR_BASE,
DIAG_ADR_ENABLED,
LOG_DIRECTORY,
LOG_LEVEL,
Index-1
cman.ora file (continued) parameters
ADDRESS,
RULE_LIST,
setting up,
,
trace parameters
TRACE_DIRECTORY,
TRACE_LEVEL,
TRACE_TIMESTAMP,
CMGW (Connection Manager Gateway), configuring
client
clients
local naming,
network service names,
Transparent Application Failover (TAF),
connection load balancing,
connection requests in a profile,
database client
database servers
directory naming,
external procedure connections,
Heterogeneous Services connections,
listeners
directory naming,
local naming,
queue size,
service information,
local naming,
multiple protocol addresses,
naming methods,
network domain, default,
network service aliases,
Index-2
configuring (continued) network service names directory naming,
external naming,
Oracle Advanced Security,
Oracle Rdb database connections,
primary and secondary instances,
quick reference,
servers
session data unit (SDU),
,
shared server,
session data unit (SDU) size,
connect-time failover
connection load balancing configuring
shared server,
Connection Time Out field in Oracle Net Manager,
connections
adjusting listener queue size to avoid errors,
concurrent, increasing number of,
connect strings, entering, dedicated servers,
directory naming,
external procedures,
Heterogeneous Services,
NIS external naming,
Oracle Rdb databases,
CONNECTIONS (CON or CONN) attribute,
D
data-dependent routing
database requests,
database resident connection pooling,
database server configuration
allocating resources with shared server,
local naming,
trace files,
database server connections syntax,
dedicated connection, dedicated server
configuring, dedicated servers
connect descriptor configuration,
described,
,
difference with shared server,
DIAG_ADR_ENABLED log parameter,
DIAG_ADR_ENABLED_listener_name log parameter,
diagnosing
direct hand-off described,
directory configuration adding users to the OracleNetAdmins group,
exporting network service names from a tnsnames.ora
file,
migrating network service names from a tnsnames.ora
directory information tree (DIT), defined,
directory naming file,
architecture,
authentication methods native,
simple,
strong,
configuring,
connecting to database services,
connecting with, connections
using the fully-qualified name of an entry,
using the relative name of an entry,
establishing a connection with, exporting
directory naming (continued) exporting (continued) network service names from a tnsnames.ora
file,
Java Database Connectivity (JDBC)
OCI drivers,
,
Java Database Connectivity (JDBC) Thin drivers,
migrating
network service names from a tnsnames.ora
file,
object classes, objects
network service aliases,
Oracle Context,
Oracle Net Manager,
OracleDBCreators group,
,
,
security,
Directory Server Migration Wizard, directory servers
directory information tree (DIT),
distinguished name (DN), entry,
Microsoft Active Directory,
Oracle Context,
relative distinguished name (RDN), security,
Directory Usage configuration option in Oracle Net
Disable Out-of-Band Break option in Oracle Net
Manager,
DISABLE_OOB networking parameter,
dispatchers
,
DISPATCHERS (DIS or DISP) attribute,
DISPATCHERS initialization parameter
CONNECTIONS attribute,
DISPATCHERS attribute,
LISTENER attribute,
MULTIPLEX attribute,
SESSIONS attribute,
Index-3
DISPATCHERS parameter
PROTOCOL attribute,
distinguished name (DN), defined,
duties of a network administrator,
E
easy connect naming
recommended for,
syntax examples,
Easy Connect naming
configuring,
entry, defined,
Environment field in Oracle Net Manager,
ENVS networking parameter,
error messages
contacting Oracle Support Services,
,
ORA-12203 sample error stack,
,
using log file to track,
error stack described,
sample,
typical layers in,
EVENT_GROUP log parameter,
Exadirect protocol configuring, exporting
network service names from a tnsnames.ora file to
external naming
configuring,
NIS,
recommended for,
Index-4
external procedures
EXTPROC_DLLS environment variable,
F
failover
Transparent Application Failover (TAF),
FAILOVER networking parameter,
FAILOVER_MODE networking parameter,
,
FTP presentation dedicated server configuration,
fully-qualified naming
Java Database Connectivity (JDBC)
OCI drivers,
with directory naming,
G
global database name
defined,
Global Database Name field in Oracle Net Manager,
GLOBAL_NAME networking parameter,
,
H
Heterogeneous Services
host naming requirements,
HTTP presentation dedicated server configuration,
I
INBOUND_CONNECT_TIMEPUT_listener_name networking parameter,
InfiniBand network communication
configuring Exadirect support,
configuring SDP protocol support,
initialization parameter file
DISPATCHERS parameter,
INSTANCE_NAME parameter,
SERVICE_NAMES parameter,
installation default configuration listeners,
local naming,
Instance Name field in Oracle Net Manager,
instance role configuration
connections to primary and secondary instances,
connections to specific instances,
INSTANCE_NAME networking parameter,
,
,
,
IPv6
connect descriptors,
TCP/IP protocol,
J
Java Database Connectivity (JDBC)
OCI drivers
fully-qualified naming support,
Thin drivers
,
fully-qualified naming support,
JavaNet layer,
JDBC
Java Database Connectivity (JDBC)
L
LISTENER (LIS or LIST) attribute,
,
Listener configuration option in Oracle Net
Configuration Assistant,
Listener Control utility commands
START,
using,
listener redirects, listener.log file,
listener.ora file log parameters
DIAG_ADR_ENABLED_listener_name,
LOG_FILE_listener_name,
parameters
INBOUND_CONNECT_TIMEOUT_listener_name,
ORACLE_HOME,
PROGRAM,
SID_NAME, trace parameters
TRACE_DIRECTORY_listener_name,
TRACE_LEVEL_listener_name,
TRACE_TIMESTAMP_listener_name,
listener.trc file, listeners
adjusting queue size for,
client load balancing,
configuring
directory naming method, external procedures,
local naming method,
nondefault address,
Oracle System Identifier,
connect-time failover,
default configuration,
increasing queue size,
handling concurrent connections,
log files
direct hand-off event information,
service registration event information,
monitoring,
,
Index-5
listeners (continued)
security
trace files,
Transparent Application Failover (TAF),
load balancing
connection,
LOAD_BALANCE networking parameter,
local naming
client configuration,
configuring,
connecting with,
database server configuration,
establishing a connection with,
listener configuration for,
recommended for,
Local Net Service Name configuration option in Oracle
LOCAL_LISTENER initialization parameter,
log files default names for,
,
Oracle Connection Manager,
sqlnet.log,
sqlnet.log for clients and database servers,
log parameters cman.ora
ADR_BASE,
EVENT_GROUP,
listener.ora
ADR_BASE_listener_name,
DIAG_ADR_ENABLED_listener_name,
LOG_DIRECTORY_listener_name,
sqlnet.ora
ADR_BASE,
LOG_DIRECTORY_SERVER,
LOG_DIRECTORY_CLIENT log parameter,
LOG_DIRECTORY_listener_name log parameter,
LOG_DIRECTORY_SERVER log parameter,
Index-6
LOG_FILE_CLIENT log parameter,
LOG_FILE_listener_name log parameter,
LOG_FILE_SERVER log parameter,
LOG_LEVEL log parameter,
Logon Authentication Protocol Version field in Oracle
,
M
maximizing data transfer, by adjusting SDU size,
METHOD networking parameter,
Microsoft Active Directory,
migrating network service names from a tnsnames.ora file to
a directory, multiple addresses
configuring client load balancing,
configuring connect-time failover,
MULTIPLEX (MUL or MULT) attribute,
N
Named Pipes protocol
NAMES.DEFAULT_DOMAIN networking parameter,
NAMES.DIRECTORY_PATH networking parameter
nis,
tnsnames,
naming method, naming methods
directory naming,
external naming,
localized,
Naming Methods configuration option in Oracle Net
net service names
,
network administrator duties,
Network Authentication (NA)
layer in error stacks,
network availability, determining,
network configuration
centralized management, localized management,
network domain, default configuring,
network information service
See
NIS
Network Interface (NI) layer in error stacks,
network performance, improving
network planning
network service aliases configuring,
described,
directory naming,
network service names configuring,
directory naming,
local naming,
multiple addresses,
,
prioritizing naming methods,
Network Session (NS), layer in error stacks,
Network Transport (NT), layer in error stacks,
networking planning internal networks availability,
networkservice names
NIS external naming configuring,
connecting with,
establishing a connection with,
O
object classes described,
Open Systems Interconnection (OSI) described,
ORA-12203 error message
sample error stack,
ORA-12526 error messages,
ORA-12527 error messages,
ORA-12528 error messages,
ORA-12535 error message,
ORA-12547 error message,
ORA-12637 error message,
Oracle Advanced Security configuring with Oracle Net Manager,
Oracle Call Interface (OCI) layer, described,
Oracle Clusterware
Oracle Connection Manager
configuring
Oracle Connection Manager computer,
protocol address for Oracle Connection
Manager,
gateway process,
log files names,
routing connections,
trace files
names,
Oracle Connection Manager Control utility commands
ADMINISTER,
STARTUP,
Oracle Context defined,
Oracle Home Directory field in Oracle Net Manager,
Oracle Net
defined,
Oracle Net foundation layer,
scalability features, shared server,
Oracle Net Configuration Assistant
Directory Usage configuration option,
listener configuration,
Listener configuration option,
local naming method,
Index-7
Oracle Net Configuration Assistant (continued)
Local Net Service Name configuration option,
Naming Methods configuration option,
network service names,
OracleContextAdmins group,
OracleNetAdmins group,
servers
starting,
Oracle Net Listener
described,
starting,
See also
Oracle Net Manager
Address List Options dialog box,
clients
default network domains,
local naming method,
Oracle Connection Manager,
described,
directory naming,
Directory Server Migration Wizard,
external procedure connections,
Heterogeneous Services connections,
Instance Name field,
listeners
Global Database Name field,
Oracle Home Directory field,
Oracle System Identifier field,
protocol addresses,
local naming method,
multiple address options,
navigating,
Net Service Name Wizard,
,
network service aliases,
network service names,
Oracle Rdb Database field,
Oracle Rdb databases
Global Database Name field,
profiles advanced options,
Check TCP/IP client access rights option,
Client Registration ID field,
Clients allowed to access field,
Index-8
Oracle Net Manager (continued) profiles (continued)
Clients excluded from access field,
Connection Time Out field,
Disable Out-of-Band Break option,
Logon Authentication Protocol Version field,
Receive operation Time Out field,
Send operation Time Out field,
Total Send Buffer field,
Turn Off UNIX Signal Handling option,
session data unit (SDU) field in Oracle Net
Manager,
Use for Heterogeneous Services option,
Oracle Net Services components
Oracle Net,
Oracle protocol support
Named Pipes,
TCP/IP with SSL,
Oracle Rdb database
configuring for connection to,
Oracle Rdb Database field in Oracle Net Manager,
Oracle Real Application Clusters connect-time failover,
Oracle schema
Oracle Support Services
Oracle System Identifier (SID) field in Oracle Net
Manager,
Oracle System Identifier, configuring on the listener,
ORACLE_HOME networking parameter,
Oracle9i Real Application Clusters connect-time failover,
FAILOVER networking parameter,
FAILOVER_MODE networking parameter,
Transparent Application Failover (TAF),
OracleDBCreators group,
,
OracleHOME_NAMECMan service,
OracleNetAdmins group,
,
OSI
See
Open Systems Interconnect (OSI)
P
packets examining trace data,
planning
internal networks availability,
port 1521 ports if not using,
presentation layer
FTP,
HTTP,
WebDAV,
primary and secondary instances,
privileged ports,
profiles (sqlnet.ora) configuring advanced options,
routing connection requests,
Program Name field in Oracle Net Manager,
PROGRAM networking parameter,
PROTOCOL (PRO or PROT) attribute,
protocol address, protocols
FTP,
HTTP,
Oracle support for,
TCP/IP,
WebDAV,
Q
queue size,
QUEUESIZE parameter for adjusting listener queue size,
R
randomizing requests among listeners,
RDB_DATABASE networking parameter,
Receive operation Time field in Oracle Net Manager,
redirect connection,
relative distinguished name (RDN),
relative naming directory naming,
Java Database Connectivity (JDBC)
OCI drivers,
resolving errors
See
troubleshooting,
routing key value,
routing connections,
RULE_LIST networking parameter,
S
SDP protocol
security database server access control configuration,
listeners
Send operation Time field in Oracle Net Manager,
server configuration
allocating resources with shared server,
log files, loopback tests, shared server,
server connections
server troubleshooting,
servers
service handlers dedicated servers,
dispatchers,
service name
Index-9
service registration benefits,
configuring,
connection load balancing,
,
service_died listener log event,
service_register listener log event,
service_update listener log event,
service_died listener log event,
SERVICE_NAME networking parameter,
SERVICE_NAMES initialization parameter,
service_register listener log event,
service_update listener log event,
SERVICES command
session data unit (SDU)
,
adjusting to improve network performance,
configuring,
field in Oracle Net Manager,
SESSIONS (SES or SESS) attribute,
shared server
compared with dedicated server,
configuring,
connect descriptor configuration parameters,
connection load balancing,
described,
,
request queue,
response queue,
virtual circuits,
SID field in Oracle Net Manager,
SID_LIST_listener_name parameter
SID_NAME networking parameter,
,
SID, configuring on the listener,
simple authentication for directory naming,
SOURCE_ROUTE networking parameter,
SQLNET.ALLOWED_LOGON_VERSION_CLIENT
SQLNET.ALLOWED_LOGON_VERSION_SERVER
SQLNET.CLIENT_REGISTRATION networking
SQLNET.EXPIRE_TIME networking parameter,
SQLNET.INBOUND_CONNECT_TIMEOUT
sqlnet.ora file log parameters
ADR_BASE,
Index-10
sqlnet.ora file (continued) log parameters (continued)
DIAG_ADR_ENABLED,
LOG_DIRECTORY_CLIENT,
LOG_DIRECTORY_SERVER,
LOG_FILE_SERVER,
parameters
NAMES.DEFAULT_DOMAIN,
SQLNET.ALLOWED_LOGON_VERSION_CLIENT,
SQLNET.ALLOWED_LOGON_VERSION_SERVER,
SQLNET.INBOUND_CONNECT_TIMEOUT,
TCP.EXCLUDED_NODES,
TCP.INVITED_NODES,
TCP.VALIDNODE_CHECKING, trace parameters
TRACE_FILE_CLIENT,
TRACE_FILEAGE_CLIENT,
TRACE_FILELEN_CLIENT,
TRACE_FILELEN_SERVER,
TRACE_FILEN0_CLIENT,
SQLNET.RECV_BUF_SIZE networking parameter,
SQLNET.RECV_TIMEOUT networking parameter,
SQLNET.SEND_BUF_SIZE networking parameter,
SQLNET.SEND_TIMEOUT networking parameter,
SSL authentication for directory naming,
START command of Listener Control utility, starting
Oracle Net Manager, static service registration,
Oracle Net Configuration Assistant,
STATUS command of Listener Control utility,
STOP command
STOP command (continued)
strong authentication for directory naming,
svr_pid.trc file,
syntax
for Listener Control utility,
for Oracle Connection Manager Control utility,
T
TAF
Transparent Application Failover (TAF)
TCP.EXCLUDED_NODES networking parameter,
TCP.INVITED_NODES networking parameter,
TCP.VALIDNODE_CHECKING networking
TCP/IP protocol described,
TCP/IP with SSL protocol described,
terminated connection detection configuring,
limitations,
terminated connection timeout
testing client configuration
TNS
Transparent Network Substrate (TNS)
TNS Time Out Value option in Oracle Net Manager,
TNS_ADMIN environment variable,
tnsnames.ora file exporting entries to directory server,
migrating entries to directory server,
parameters
INSTANCE_NAME,
LOAD_BALANCE,
SDU,
TYPE_OF_SERVICE,
TNSPING utility
compared to TRCROUTE utility,
TNSPING.TRACE_DIRECTORY trace parameter,
TNSPING.TRACE_LEVEL trace parameter,
Total Receive Buffer field in Oracle Net Manager,
Total Send Buffer field in Oracle Net Manager,
Trace Assistant
trace data for packets, trace data statistics, trace files
analyzing with Trace Assistant,
error message information,
examining with Trace Assistant,
svr_pid.trc for servers, trace parameters
cman.ora
TRACE_FILELEN,
TRACE_FILENO,
listener.ora
TRACE_DIRECTORY_listener_name,
TRACE_LEVEL_listener_name,
TRACE_TIMESTAMP_listener_name,
sqlnet.ora
TRACE_FILE_CLIENT,
TRACE_FILEAGE_CLIENT,
TRACE_FILELEN_CLIENT,
TRACE_FILELEN_SERVER,
TRACE_FILENO_CLIENT,
TRACE_DIRECTORY trace parameter,
TRACE_DIRECTORY_CLIENT trace parameter,
Index-11
TRACE_DIRECTORY_listener_name trace parameter,
TRACE_DIRECTORY_SERVER trace parameter,
TRACE_FILE_CLIENT trace parameter,
TRACE_FILE_listener_name trace parameter,
TRACE_FILE_SERVER trace parameter,
TRACE_FILEAGE_CLIENT trace parameter,
TRACE_FILEAGE_listener_name trace parameter,
TRACE_FILEAGE_SERVER trace parameter,
,
TRACE_FILELEN trace parameter,
TRACE_FILELEN_CLIENT trace parameter,
TRACE_FILELEN_listener_name trace parameter,
TRACE_FILELEN_SERVER trace parameter,
TRACE_FILENO trace parameter,
TRACE_FILENO_CLIENT trace parameter,
TRACE_FILENO_listener_name trace parameter,
TRACE_FILENO_SERVER trace parameter,
TRACE_LEVEL_CLIENT trace parameter,
TRACE_LEVEL_listener_name trace parameter,
TRACE_LEVEL_SERVER trace parameter,
TRACE_TIMESTAMP trace parameter,
TRACE_TIMESTAMP_CLIENT trace parameter,
TRACE_TIMESTAMP_listener_name trace parameter,
TRACE_TIMESTAMP_SERVER trace parameter,
TRACE_UNIQUE_CLIENT trace parameter,
Transparent Application Failover (TAF)
configuring,
GLOBAL_DBNAME networking parameter in listener.ora,
overview,
Transparent Network Substrate (TNS) benefits,
described,
TRCROUTE utility described, troubleshooting
troubleshooting (continued) loopback tests,
TTC
See
Two-Task Common (TTC)
Turn Off UNIX Signal Handling option in Oracle Net
Manager,
TWO_TASK environment variable,
Two-Task Common (TTC) presentation
dedicated server configurations,
shared server configurations,
TYPE networking parameter,
Type of Service field in Oracle Net Manager,
TYPE_OF_SERVICE networking parameter,
,
U
Use for Heterogeneous Services option in Oracle Net
Manager,
,
V
V$SESSION table,
W
WebDAV presentation
dedicated server configurations,
shared server configurations,
WebDAV protocol,
Windows NT services
wizards
Directory Server Migration,
Oracle Net Manager,
Y
ypserv program,
Index-12
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