sql 2008 r2 mirroring timeout expired

I have setup High Availability mirroring on two SQL 2008 R2 servers for SharePoint 2010. I see lot of sql connection time out err开发者_高级运维ors in the eventlog. If I turn off the mirroring the errors go away.

Also, I only have sql server standard edition which only allows sync mirroring so async mirroring is not an option as of now.

Exact error is this: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

This may be relevant:

http://blogs.msdn.com/b/dipanb/archive/2011/05/14/you-may-see-an-instant-timeout-when-connecting-to-a-mirrored-database-from-a-net-application.aspx

http://technet.microsoft.com/en-us/library/cc263314%28office.12%29.aspx

You need to investigate this as any performance problem: statements are taking too long to complete and they hit the default .Net 30 seconds command timeout. The Waits and Queues methodology still applies here, just as with any performance investigation. You have a good head start from knowing that the problem occurs only when mirroring is enabled, so that should help you narrow down the problem. A reasonable guess would be that your mirror server IO subsystem is not capable of keeping up with the rate of writes from the primary. With mirroring your COMMIT have to wait on the mirror to harden the log, so the LDF drives on the mirror are a performance bottleneck if they are not fast enough. Follow the methodology linked above to confirm or deny this hypotheses, and once you find out the the real problem, then you can take measures accordingly.