Thread using 50-100% CPU usage : MSVCR80.dll!endthreadex

Question

I have sql 2005 sp1, and have been noticing a lot of MSVCR80.dll!endthreadex threads using Process Explorer taking all of the CPU on the server and they never go away until you either kill it, or restart sql server? Does any one know any work around as in like how to end it or stop it coz this happens everyday.

Answer 1

This was a really good article about using Process Explorer & ProcMon to track down a similar problem:

The Case of the Slow System

Answer 2

MSVCR80.dll!endthreadex doesn't mean anything significant. The MSVCR80 DLL is used to execute C++ code compiled with Visual Studio 2005 (and I'm guessing that SQLServer 2005 was compiled in Visual Studio 2005). You could check to make sure that you have the latest C++ Redistributable package installed.

SQLServer will start up worker threads as it runs. This is normal. If you are seeing these threads take up CPU then it means YOUR DATABASE IS DOING WORK. Users are querying the database or the database is trying to resolve internal work that it can't complete because you keep restarting it.

Using Process Explorer to diagnose SQLServer performance problems isn't going to get you very far. You should use the SQL Server Profiler to identify what work is being done in the database.