Product:
Cognos Controller 10.2.1
Microsoft Windows 2012 R2
Microsoft SQL 2012 database in cluster setup

Symptom:
After the SQL cluster have rolled from Node A to Node B, then the first Controller user to login and run a standard report get an error message. He run the report a second time and it gives the same error message. The third time he run the report it works fine. Same issue for other reports.
Thereafter the reports work fine inside Cognos Controller, until next time you role the Cluster.

Error Message:
RQP-DEF-0177
Ett fel inträffade när åtgärden ‘sqlStart’ status=’-121’ utfördes.
UDA-SQL0564 [Microsoft OLE DB Provdier for SQL Server][DBNETLIB]
General network error.
(SQLSTATE=08S01, SQLERRORCODE=11)

Solution:
After you have shifted the SQL cluster, restart the Cognos BI service on the Application server.
Wait the 5 minutes it takes to restart the IBM Cognos service, and then login to Cognos Controller client and test again to run report. Now it should work the first time.

The Cognos BI service check if it have contact with the database, if it loose contact – it will not use that node for some time.

More information:
http://www-01.ibm.com/support/docview.wss?uid=swg21378301