Guru's Guide to SQL Server Architecture and Internals, The

DBCC SQLPERF(umsstats)

I mentioned DBCC SQLPERF(umsstats) earlier, and you may already be aware of it given that, although it's undocumented, it's mentioned in the public Microsoft Knowledge Base. DBCC SQLPERF(umsstats) allows you to return a result set listing statistics for the visible UMS schedulers on the system. It can list the total number of users and workers for the scheduler, the number of workers on the runnable list, the number of idle workers, the number of outstanding work requests, and so on. It's very handy when you suspect you're experiencing some type of issue with a scheduler and need to know what's going on behind the scenes. For example, you should be able to quickly tell from this output whether a scheduler has reached its ...