Tomcat JDBC Data Source Memory Leak Issue

Your Tomcat application log indicates a potential memory leak related to the JDBC data source. This issue arises when the web application registers a JDBC driver but fails to unregister it upon its shutdown.

JDBC Driver Unregistration

To address the first error, the JDBC driver has been forcefully unregistered to prevent a memory leak. However, this suggests that the destroy-method in your configuration is not being invoked correctly. Please ensure that the destroy-method="close" attribute is set correctly in the element for the data source.

MySQL Statement Cancellation Timer Thread

The second error pertains to a thread named "MySQL Statement Cancellation Timer" that was started but not stopped by the web application. This thread is typically used to cancel pending database operations. The error message suggests that the thread was not properly terminated, which could lead to a memory leak.

Potential Solution

To resolve the issue with the MySQL Statement Cancellation Timer thread, try the following:

• Ensure that all threads created by your web application are properly closed or terminated upon shutdown.
• Verify that the data source configuration is correct and that the connection pool is being properly managed.
• Consider placing the MySQL Connector/Driver JAR file in the Tomcat directory instead of within the WAR file. This can ensure that the driver is not reloaded and recreated multiple times during deployment, which could cause thread leaks.

Please refer to the following resources for additional information:

• [JDBC Driver Placement](https://tomcat.apache.org/tomcat-7.0-doc/jndi-resources-howto.html#JDBC_Driver_Placement)
• [Configuring Tomcat with MySQL](https://tomcat.apache.org/tomcat-7.0-doc/tomcat-jdbc.html#Configuring_Tomcat_to_Connect_with_MySQL)