Zombie threads eating my brainz (J2EE, Tomcat, Hibernate, Quartz)

• Try to increase the logging level of org.quartz.simpl.SimpleThreadPool to debug to get more information.

• If that does not work, try a logging listener. Quartz has a JobListener interface, which is specified in its tutorial. A listener can help you trace job execution. Maybe jobs just don't finish and get deadlocked.

• Configure org.quartz.threadPool.threadCount to stop running out of threads.

update:

• Also, you might want to take a thread dump and see the thread stats. visual vm has a plugin called TDA, or you can use Thread dump analyzer directly.

• Just in case, check the quartz version to see if there is no known bug.