Hello,

I have two SQL servers SQLA (Principal) and SQLB(Mirror). (SQL 2012 Standard on Win2K12R2).

During fail over from SQLA (Principal) -> SQLB(Mirror) occurs, the application is able to access the mirror copy and runs fine. Strangely in the Principal server every second there is the following eventid,

2015-07-28 16:29:00.17 Logon       Error: 18456, Severity: 14, State: 38.
2015-07-28 16:29:00.17 Logon       Login failed for user 'Domain\Account'. Reason: Failed to open the explicitly specified database 'DB_name'. [CLIENT: X.X.X.X]

Shouldn't after the fail over SQL should access the mirror server? any help appreciated!

Regards,

Harish Kumar

Make sure your user(Domain\Account) is having the same level of permissions on bot servers.

If it is a Active directory user make sure same permissions on both servers.

If it is SQL user make sure the SID is same on both servers.

Thanks your reply!

Both the servers belong to the same AD and service accounts are the same. I have verified the permissions and they are the same for both servers.

Harish Kumar

Hi,

Is there any agent jobs running on Principal server which is trying to access the database?

Hi Praveen,

That was my doubt too, during the course of the troubleshooting I stopped the agent service and tried, still the event id kept occurring. I m checking if there any other jobs etc., running in the primary server.

Any other hints would be helpful!

Harish Kumar

Hi,

I think SQL trace can help you to identify this.

Basically an Error state above 18 needs attention from CSS engineers.

http://blogs.msdn.com/b/sql_protocols/archive/2006/02/21/536201.aspx

Or it might be the connection string used by a client application. Run Profiler to find the client IP and process id.
Then login to that client machine and the check the process id in Task Manager.
After you identified the client application, fix it.

Hello All,

Checked in the profiler trace, looks like only one DB has this issue. All the other DB's initially the error occurs but stops after a while. The particular DB in question is a SharePoint search DB (All the other Db's are SharePoint Db's). Being a SharePoint guy, in the SharePoint logs I don't see any errors. It seem to connect to the fail over server server. There is no outage or connection failures.

On a side note, this DB has 300+ connections? Will mirroring take time to transfer all the connections to the other node during the failover?

Harish Kumar