Sql-server – Apply the latest Service Pack and Cumulative Update

For the latest CU and builds (this article will also include service packs when released): SQL Server 2014 build versions

As of 2015-01-13, SQL Server 2014 is currently on CU5, which was released Dec. 17, 2014.
Service pack 1 has not yet been released.

Another similar article, specific to Service Packs: How to obtain the latest service pack for SQL Server 2014

The logs led us to review our Cluster services:

There was an error to lookup cluster resources. Error: There was a failure to call cluster code from a provider. Exception message: Generic failure . Status code: 4104. Description: .
HResult : 0x86d80014
FacilityCode : 1752 (6d8)
ErrorCode : 20 (0014)
Data:
    errorMessage = There was a failure to call cluster code from a provider. Exception message: Generic failure . Status code: 4104. Description: .

We determined that the replication agent service was the cause of the incomplete installation.

We removed the service from Cluster Resources and re-applied SP2 without success. We stopped the service on the node and re-applied SP2 without success.

Error: Failed to run patch request for instance: MSSQLSERVER (exit code: -2032664552)

We uninstalled the service from the server nodes, and then successfully "re-applied" SP2.

Follow-up actions:

1. We'll be contacting the replication agent vendor to discuss why this was required.
2. Review the Microsoft document "Patching SQL Server Failover Cluster Instances with Cluster-Aware Updating (CAU)", available here, which I discovered today.