SQL Server 2005: Sudden Performance Degradation on Database Mirror
Posted on 2012-03-15
Currently looking into an issue on a SQL Server 2005 (x64 Ent SP2 CU13) database mirror environment that suffers a significant performance degradation at regular intervals. This degradation occurs suddenly over a period of 5 minutes.
Failing over to the other database ALWAYS clears the issue, suggesting that there is a high probability of this being a caching issue.
Examining the various caches shows that the TokenAndPermUserStore is approaching 1GB in size; spinlock statistics also show a large number of spins, collisions and backoffs (this is in fact a negative number, not seen that before) for MUTEX.
I am aware that there were performance issues associated with the TokenAndPermUserStore cache that should have been resolved by the above build if memory serves correctly but the experience of other DBAs highlighted in various forums suggests that this may not be the case.
Has anybody seen any similar issues or can offer confirmation as to what build of SQL 2005 provided a concrete fix for the security cache issue?