Setting up a cluster with multiple tenants

The following circumstances require that you set up a cluster with multiple tenants:

• 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 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. 
• (Optional) The Centralized Configuration Server is configured.
• Tenant AR Configuration servers are configured in the mid tier.

Best practices

• 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 Tier s in the cluster.

• Change the arsystem.ehcache.referenceMaxElementsInMemory property value (located in 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.

To set up a cluster with multiple tenants

1. Ensure that only one mid tier is up and running in the cluster.
2. Enable preload for all Tenant AR Configuration servers on this Mid Tier .

3. Start the preload for all Tenant AR Configuration servers by clicking the Preload button for each Tenant AR Configuration server on the Cache Settings page.

   Preload is a time-intensive process. For example, if you have eight tenants, preload might take one hour to complete on all the tenants.

4. Verify that the preload is completed successfully for all Tenant AR Configuration servers.
   

   If any the preload statuses is Aborted, click the Preload button to start preload again for that Tenant AR Configuration server.

5. Wait for the mid tier CPU to almost reach 0%.
6. Disable preload on all Tenant AR Configuration servers by clearing the Preload check box on the AR Server Settings > Edit AR Server page.

7. Gracefully shut down Tomcat.

   For 8 tenants, it takes about 10 minutes to shut down Tomcat.

   Warning

   Do not kill the Tomcat process. As an example, for 8 tenants, it takes about 10 minutes to shut down Tomcat.

   
   

8. Verify whether the shutdown_completed status appears in the midTierInstallation/cache.lck file.
9. Use the cache Backup utility to back up and restore the good cache on other mid tiers in the cluster.