Change Tracking fixes in SQL 2014 SP4 CU4

The Cumulative Update 4 for SQL 2014 SP3 contains these important fixes for Change Tracking technology.

Cumulative Update Package 4 for SQL Server 2014 SP3 – KB4500181
https://www.microsoft.com/en-us/download/details.aspx?id=57663

FIX: Tlog grows quickly when you run auto cleanup procedure in SQL Server 2014, 2016 and 2017
https://support.microsoft.com/en-us/help/4500403/fix-tlog-grows-quickly-when-you-run-auto-cleanup-procedure-in-sql-serv

FIX: Syscommittab cleanup causes a lock escalation that will block the syscommittab flush in SQL Server 2014, 2016 and 2017
https://support.microsoft.com/en-us/help/4512016/fix-syscommittab-cleanup-causes-a-lock-escalation-that-will-block-the

The “fix list” article contains links for installing in cluster and mirroring topology.

Cumulative Update 4 for SQL Server 2014 SP3

https://support.microsoft.com/en-us/help/4500181/cumulative-update-4-for-sql-server-2014-sp3

• SQL Server failover cluster rolling update and service pack process
  
• How to apply a hotfix for SQL Server in a transactional replication and database mirroring topology
  
• How to apply a hotfix for SQL Server in a replication topology
  
• How to install service packs and hotfixes on an instance of SQL Server that is configured to use database mirroring
  

Always On Availability Groups

In the “rolling upgrade for Always On” an extra step is required to ensure replication components are upgraded on Primary Replica. This is not required when apply the Cumulative update is directly installed on an active SQL Server as CU install will automatically run sp_vupgrade_replication. This is only required as part of rolling-upgrades where “read-only” secondary servers are upgraded prior to failover.

https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/upgrading-always-on-availability-group-replica-instances
Run the following Transact-SQL on the instance that hosts the primary replica:
EXECUTE [master].[sys].[sp_vupgrade_replication];

Chris Skorlinski, SQL Server Escalation Services