Recently we were installing SQL Server 2012 SP1 CU6 to fix the slow performance when you run the SSIS Server Maintenance Job to remove old data in SQL Server 2012, you can read about the issue here. We ran into a serious issue where the installation failed and couldn’t start SQL Server services.
Let me first describe the server, it is a named instance of SQL Server 2012 SP1 Engine and SSIS with AlwaysOn Availability Group, primary instance in main data center and secondary replica in DR site. The AG comprises all databases and SSISDB.
SQL 2012 SP1 CU6 installation failed with the following error:
Script level upgrade for database ‘master’ failed because upgrade step ‘SSIS_hotfix_install.sql’ encountered error 945, state 2, severity 25. This is a serious error condition which might interfere with regular operation and the database will be taken offline. If the error happened during upgrade of the ‘master’ database, it will prevent the entire SQL Server instance from starting. Examine the previous errorlog entries for errors, take the appropriate corrective actions and re-start the database so that the script upgrade steps run to completion.
The issue was related to configuring SSIS db “SSISDB” with AlwaysON Availability Group. So what happened is that SQL Server service packs usually run in single-user mode, while an availability database must be a multi-user database. Therefore, during installing the CU6, all availability databases including SSISDB will be taken OFFLINE which become inaccessible and thus fail the patch.
To workaround this issue, here are the steps:
- Start SQL Server service with Trace Flag 902:
- >Net Start MSSQL$InstanceName /T902
- Open SQL Server Management Studio, go to Availability Group and remove SSISDB from the availability databases
- Open New Query, execute the SSIS_hotfix_install.sql script which can be found in Install folder under \Program Files\Microsoft SQL Server\MSSQL11.MSSQL$InstanceName \MSSQL
- Stop SQL Server services:
- >Net Stop MSSQL$InstanceName
- Start SQL server service from SQL Server configuration manager
- Add SSISDB back to Availability Group
That’s all and we are back in business. Click here from more information on how you can make use of SSIS and AlwaysOn Availability Groups.