How a clustered instance of Analysis Services works
Analysis Services is clustered as a generic service resource on a Windows failover cluster. This applies to 2005, 2008, 2008R2, and 2012.
Since SSAS 2005 version, Analysis Services is fully integrated into clustering Setup (the install of SQL):
- SSAS 2005 cluster setup is adding the service on all cluster nodes on the same setup
- SSAS 2008, the setup have to be done node by node Analysis Services is presented to the cluster as generic resource with the type Application Service and doesn’t implement his own explicit IsAlive method. Unlike SQL Server, Analysis Services doesn't have a cluster resource .dll that knows how to do that work like connect to AS and run a simple query to check that it responds.
Possible cause of failure that is detected for an Application Service:
- The service stopped(ie. crash, or was killed) then the cluster resource would notice
- A dependency in the group where the generic service is configured failed (a disk fails or goes offline, an IP, virtual name, mount point, SQL server…other dependencies affecting the group)
Note : Application Service will NOT detect a hang situation in SSAS, where all connections are rejected.
Michel Degremont | Premier Field Engineer - SQL Server Core Engineer |