Hi Folks,

It has been a long time since my last post, and i would like to give tip about a problem that i had a few weeks ago. SQL Server was running on Hyper-V and the costumer was always complaining about performance in certain times of day, as we know SQL Server has a dmv called sys.dm_os_wait_stats. Looking to this DMV i saw a high use of THREADPOOL. According BOL THREADPOOL is:

“Occurs when a task is waiting for a worker to run on. This can indicate that the maximum worker setting is too low, or that batch executions are taking unusually long, thus reducing the number of workers available to satisfy other batches.”

After that, the only configuration that i know (might have more than one) is in the Server Properties the option “Maximum Worker Threads”.

As you can see in the picture the “Maximum worker threads” was setup with 128 workers, so i just put the value 0 (zero) because zero is the same meaning of default for this configuration and after that the high use of THREADPOOL disappeared and of course the SQL Server on Hyper-V is working fine again.

Best Regards,
Marcos Freccia