Recently I’ve build a Windows 2008 R2 file&print cluster which had a generic service as well, we noticed a lot of memory was used by the active machine so I went on searching for an explanation and found the following knowledge base article

Consider the following scenario:

• An application or service frequently uses the Windows Management Instrumentation (WMI) interface to query a Windows Server 2008 R2 failover cluster for hosted virtual machine information by using one of the following commands:
  Select * from MSCluster_Resource where Type = ‘Virtual Machine’ and PrivateProperties.VmID = ‘id’
  Select * from MSCluster_Resource where Type = ‘type1 ‘ [OR type = ‘typeN’ ]*
  Select * from MSCluster_Resource where Type = ‘Generic Service’ and PrivateProperties.ServiceName = ‘ServiceName’
  Select * from MSCluster_Resource where Type = ‘Virtual Machine Configuration’ and PrivateProperties.VmId = ‘id’
• Hotfix package 974930 is installed on the queried cluster node.

In this scenario, the memory usage of one Wmiprvse.exe process keeps increasing every time WMI queries are conducted. With time, the Wmiprvse.exe process terminates. Because of this issue, the application or service experiences low performance or function failure.

I’ve downloaded the hotfix and installed it on both nodes and the memory leak was gone.