Setting up a cluster with multiple tenants
You must set up a cluster with multiple tenants in the following circumstances:
- Creating a new cluster environment
- Migrating to a cluster environment
- Setting up new hardware
- Testing a cluster for performance
You can also add global and local level configurations for the tenants. Local level configurations are applicable for a particular tenant in a cluster. Global level configurations are applicable for all tenants in a cluster. For more information about local and global level configurations, see Managing AR Server Group components by setting global-level and local-level configurations.
Before you begin
Ensure that the following prerequisites are met:
- Mid tiers are configured in a cluster.
- Optionally, Centralized Configuration Server is configured.
- Tenant AR Configuration servers are configured in the mid tier.
- Set the Maximum Heap Size property value based on the number of tenants. For example, if you are setting up a cluster with 8 tenants, ensure that the Maximum Heap Size is 6 GB for all the mid tiers in the cluster.
- Change the arsystem.ehcache.referenceMaxElementsInMemory property value ( located at C:\Program Files\BMC Software\ARSystem\midtier\WEB-INF\classes\config.properties ) based on the number of tenants. For example, for 8 tenants, set the value of this property to 14000. For more information, see in the BMC Remedy ITSM Deployment documentation.
For information on other recommendations, see <white_paper_TBD>.
To set up a cluster with multiple tenants
- Ensure that only one mid tier is up and running in the cluster.
- Enable preload for all Tenant AR Configuration servers on this mid tier.
Start the preload for all Tenant AR Configuration servers by clicking the Preload button for each of the Tenant AR Configuration server on the Cache Settings page.
Preload is a time-intensive process. It might approximately take an hour for the preload to complete for all tenants. For example, if you have 8 tenants, preload takes an hour to complete on all the tenants.
Verify that the preload is completed successfully for all Tenant AR Configuration servers.
If any one of preload statuses is Aborted, start preload again for that Tenant AR Configuration server by clicking the Preload button.
- Wait for the mid tier CPU to almost reach to 0%.
- Disable preload on all Tenant AR Configuration servers by clearing the Pre-load check box on the AR Server Settings > Edit AR Server page.
Gracefully shut down Tomcat.
Do not kill the Tomcat process. As an example, for 8 tenants, it takes about 10 minutes to shut down Tomcat.
- Verify whether the shut down status shutdown_completed appears in the <midtierInstallation>/cache.lck file.
- Use the cache Backup utility to back up and restore the good cache on other mid tiers in the cluster.