If you’ve been using Tomcat’s shutdown.sh script and find that Tomcat hasn’t stopped, it’s probably because there are some non daemon threads still running. The JVM will not shut down until there are no active non daemon threads.

Try the following to diagnose and resolve the problem….

Find Tomcat’s process id:

ps -ef | grep tomcat

Now kill the Tomcat process using the -3 flag (SIGQUIT signal) to force a thread dump:

kill -3 tomcat process id number goes here

Once the process has stopped take a look at the tomcat log file. You should see some thread dumps which will help to identify the application and code that is hanging on to threads.