Advance Availability(AA) for high availability of application introduced in CA Service Desk Manager R12.9 (CA SDM) is useful during the installation of cumulative patches as well as schema changes. Following steps demonstrates usage of the feature.
A simple example of the AA environment with four server’s i.e.
1. Stand By Server (SB)
2. Back Ground Server (BG)
3. Application Server (APP - can be increased as per the environment requirement)
4. Database server (DB)
Note: Before you start this procedure please verify the Admin Guide Considerations mentioned for AA configurations.
The following instructions outline how to perform Schema changes using Web Screen Painter(WSP) on an AA Configuration Environment.
1. Open Web screen painter on Background server and make the necessary changes (Adding New Tables / Columns etc.) and click ‘save and publish’
For example lets add a column to CR Object (Call_Req Table)
2. Run the command ‘pdm_server_control -v’ from Command Prompt to suppress the version control on the Background server
Note: Run “pdm_server_control –t” command which will give you results of the server status (Background / Standby)
3. Start the Standby Server services either from the services window or command prompt.
4. Run the command ‘pdm_server_control -b’ on Original Standby server to promote the Background server as the new Standby server
5. On the old Background (current Standby), Executing ‘pdm_publish’ command will complete WSP Schema changes.
Press 'Y' (Yes) to complete the schema modifications on the original Standby Server)
The following screenshot explains that fail-over has completed successfully.
Important: Following the procedure aforesaid, ensure to perform Rolling Maintenance on Application Servers