FIX: No automatic failover after database mirroring stops unexpectedly in SQL Server

Applies to: SQL Server 2012 Business IntelligenceSQL Server 2012 DeveloperSQL Server 2012 Enterprise

Symptoms


Assume that you set up a database mirroring session in SQL Server 2012,2014 or 2016. You add a witness to support automatic failover. In a rare situation, the mirroring session may stop, and then the data is no longer synchronized. Additionally, an automatic failover doesn’t occur as expected.

Resolution


Update information

This issue is fixed in the following cumulative updates for SQL Server:

  Cumulative Update 2 for SQL Server 2016 SP1

  Cumulative Update 4 for SQL Server 2016

  Cumulative Update 3 for SQL Server 2014 SP2

  Cumulative Update 10 for SQL Server 2014 SP1 

  Cumulative Update 6 for SQL Server 2012 Service Pack 3
 

Workaround


To work around this issue, resume the mirroring session. To do this, type each of the following Transact-SQL statements, and then press Enter after each statement:

ALTER DATABASE database_name SET PARTNER SUSPEND
GO
ALTER DATABASE database_name SET PARTNER RESUME
GO

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 that Microsoft uses to describe software updates.