How to Resolve Tomcat JDBC Data Source Memory Leak Issues?

Tomcat JDBC Data Source Memory Leak Issue

When shutting down Tomcat, users may encounter an error in the catalina.out log file indicating a potential memory leak due to an unregistered JDBC driver ("This is very likely to create a memory leak"). Additionally, a separate error message may reference a thread named "MySQL Statement Cancellation Timer" failing to stop, also leading to a possible memory leak.

JDBC Driver Unregistration

The error regarding the unregistered JDBC driver is thrown when the web application fails to remove the driver during shutdown. Despite configuring the destroy-method in the Spring bean configuration, this issue may still occur. To resolve this, it is recommended to move the SQL Connector/Driver to the tomcat/lib folder instead of including it in the war file. This ensures that the driver is shared among all web applications, eliminating the need for multiple instances and potential memory leaks.

MySQL Statement Cancellation Timer

The second error message pertains to the "MySQL Statement Cancellation Timer" thread. This thread is created by the JDBC driver to periodically check if any active statements are being canceled. However, the thread may not terminate properly upon application shutdown, leading to a memory leak.

To resolve this issue, ensure that the application explicitly closes all database connections before shutting down. This can be achieved by implementing a ConnectionPoolListener that closes all connections on web application undeploy. Additionally, it is recommended to configure a shutdown callback that waits for all open connections to terminate gracefully before stopping the thread and allowing the application to exit cleanly.

The above is the detailed content of How to Resolve Tomcat JDBC Data Source Memory Leak Issues?. For more information, please follow other related articles on the PHP Chinese website!