Architecture
2.5 Process Workflows
When tasks are performed such as logging in or scheduling an object, information flows through the system and the servers communicate with each other. The following section describes some of the process flows as they would happen in the Information platform services system.
2.5.1 Startup and authentication
2.5.1.1 Logging on to Information platform services
This workflow describes a user logging on to a Information platform services web application such as the Central Management Console (CMC) from a web browser.
1.
The browser (web client) sends the login request via the web server to the web application server, where the web application is running.
2.
The web application server determines that the request is a logon request. The web application server sends the username, password, and authentication type to the CMS for authentication.
3.
The CMS validates the username and password against the appropriate database. In this case,
Enterprise authentication is used, and user credentials are authenticated against the CMS system database).
4.
Upon successful validation, the CMS creates a session for the user in memory.
5.
The CMS sends a response to the web application server to let it know that the validation was successful.
6.
The web application server generates a logon token for the user session in memory. For the rest of this session, the web application server uses the logon token to validate the user against the CMS.
The web application server generates the next web page to send to the web client.
7.
The web application server sends the next web page to the web server.
8.
The web server sends the web page to the web client where it is rendered in the user's browser.
2.5.1.2 SIA start-up
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Architecture
A Server Intelligence Agent (SIA) can be configured to start automatically with the host operating system, or can be started manually with Central Configuration Manager (CCM).
A SIA retrieves information about the servers it manages from a Central Management Server (CMS).
If the SIA uses a local CMS, and that CMS is not running, the SIA starts the CMS. If a SIA uses a remote
CMS, it attempts to connect to the CMS.
Once a SIA is started, the following sequence of events is performed.
1.
The SIA looks in its cache to locate a CMS.
a.
If the SIA is configured to start a local CMS, and the CMS is not running, the SIA starts the CMS and connects.
b.
If the SIA is configured to use a running CMS (local or remote), it attempts to connect to the first
CMS in its cache. If the CMS is not currently available, it attempts to connect to the next CMS in the cache. If none of the cached CMSs are available, the SIA waits for one to become available.
2.
The CMS confirms the SIA's identity to ensure that it is valid.
3.
Once the SIA has successfully connected to a CMS, it requests a list of servers to manage.
Note:
A SIA does not store information about the servers it manages. The configuration information that dictates which server is managed by a SIA is stored in the CMS system database and is retrieved from the CMS by the SIA when it starts.
4.
The CMS queries the CMS system database for a list of servers managed by the SIA. The configuration for each server is also retrieved.
5.
The CMS returns the list of servers, and their configuration, to the SIA.
6.
For each server configured to start automatically, the SIA starts it with the appropriate configuration and monitors its state. Each server started by the SIA is configured to use the same CMS used by the SIA.
Any servers not configured to start automatically with the SIA will not start.
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2.5.1.3 SIA shutdown
You can automatically stop the Server Intelligence Agent (SIA) by shutting down the host operating system, or you can manually stop the SIA in the Central Configuration Manager (CCM).
When the SIA shuts down, the following steps are performed.
• The SIA tells the CMS that it is shutting down.
a.
If the SIA is stopping because the host operating system is shutting down, the SIA requests its servers to stop. Servers that do not stop within 25 seconds are forcefully terminated.
b.
If the SIA is being stopped manually, it will wait for the managed server to finish processing existing jobs. Managed servers will not accept any new jobs. Once all jobs are complete, the servers stop. Once all servers have stopped, the SIA stops too.
During a forced shutdown, the SIA tells all managed servers to stop immediately.
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