FIX: Parallel redo does not work after you disable Trace Flag 3459 in an instance of SQL Server

Applies to: SQL Server 2017 DeveloperSQL Server 2017 EnterpriseSQL Server 2017 Enterprise Core More

Symptoms


Assume that you use Always On Availability Groups in Microsoft SQL Server. After you switch to serial redo from parallel redo by enabling Trace Flag 3459, serial redo works as expected. However, when you switch back to parallel redo by disabling Trace Flag 3459, parallel redo does not work. If you restart the instance of SQL Server, parallel redo works as expected.

Resolution


This problem is fixed in the following update for SQL Server:

Cumulative Update 9 for SQL Server 2017 

Cumulative Update 2 for SQL Server 2016 Service Pack 2

Cumulative Update 10 for SQL Server 2016 Service Pack 1

Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References


Learn about the terminology Microsoft uses to describe software updates.