One of my db server SQLCONNECTIONPOOL growing very huge,it consumed 55GB , out of 65Gb (sql MAX) memory) Environment: Microsoft SQL Server 2017 (RTM-CU25) Standard Edition enter image description here

enter image description here How can i reduce the SQLCONNECTIONPOOL size ?

2 Answers 2


In my experience it was a driver problem.

Basically, some application is calling sp_prepare system procedure through an JDBC driver and do not call sp_unprepare. This seems to be a bug in the JDBC driver. There’s not much to do on the MSSQL server.

So try to see if you are using the last version of jdbc driver.

  • 2
    In this case, the driver is JDBC instead of ODBC. This could be is symptom of either a driver issue (updating the to latest driver may help) or, more likely, an application bug leaking prepared statement handles. A SQL trace may help identify missing sp_unprepare calls.
    – Dan Guzman
    Apr 26 at 10:55
  • Thanks for sharing the experience. I had a meeting with application team and suggested them to update the JDBC drivers. while waiting for drivers update, we have restarted the Tomcat services to see if it brings down the SQLCONNECTIONPOOL size. It indeed brought down the SQLCONNECTIONPOOL size to 50MB initially.. i.stack.imgur.com/iwauQ.png)](https://i.stack.imgur.com/… Apr 27 at 13:52

So finally we applied permanent fix. I convinced my application team to update the JDBC drives to latest on application server. After that, the issue got disappeared. Now the sqlconnectionpool size is less than 10MB. Thanks you @mbuschi and @Dan Guzman

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