Symptoms
Consider the following scenario:
-
You have some applications connect to Microsoft SQL Server 2012 or SQL Server 2014 that use connection pooling.
-
There are many distinct or different logins that are used by applications to connect to SQL Server.
-
The application has a very frequent connect-query-disconnect pattern. In Perfmon, the MSSQL$<instancename>:General Statistics -> Connection Reset/sec value is in thousands. SQL Server runs a stored procedure that's named sp_reset_connection to clean up and reset the connection state for the pooled connection so it can be used by the new login.
In this scenario, you may experience a performance decrease or throughput and a high CPU usage on SQL Server.Note: If you're monitoring wait statistics, you may also notice an increase in the CMEMTHREAD wait type during the affected timeframe. Note This issue doesn't occur if the login(s) belongs to the sysadmin role. To protect the instance of SQL Server and the data that's stored on it, we suggest you to have logins with minimal required privileges.
Resolution
Cumulative Update information
The issue was first fixed in the following cumulative update of SQL Server.
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. We recommend that you download and install the latest cumulative updates for SQL Server:
Registry informationTo use the hotfix in this package, you don't have to make any changes to the registry.
Restart requirementYou may have to restart the computer after you apply this hotfix.
Hotfix replacement information This hotfix doesn't replace a previously released hotfix.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
