I am using Activti in tomcat. Everything works as intended but I have a very intriguing problem. The Activiti engine freezes after 1-2 hours and nothing happens after that until I restart the tomcat. There are no exceptions thrown..no error log etc. It just stops working. It is not the memory usage in tomcat either as all other applications keep working, only the applications which use Activiti engine stop working. Can someone throw a few pointers where I should start looking in the absence of any clues…………?