Hi, > I have verified that the session is never closed
I think the problem is not closing sessions, it is opening many sessions (and then not closing them). > Ticket is a unique ID everytime a session is opened. How many sessions do you open, and how many do you close? With the YourKit profiler, you could find out how many sessions are open. However I suggest to add System.out whenever you open and close a session. Did you have a look at my test case? It doesn't run out of memory on my machine. The number of caches stays at '6' where in your case the number of caches increases until you run out of memory. Thomas
