The application is running on apache tomcat 7.0.37. It is a Java/GWT application using JPA and MySql. 

Sometimes we find it completely unresponsive. Today was the 2nd time it happened in 5 months. It works fine after restart. Both the time this behavior is observed when traffic was less.

I analyzed the thread dump and do not find any deadlocks.

Any help on approaching the problem is appreciated.

Thanks,
Kisor