What can be done with 'PermGen out of space' exception in Tomcat-Spring-Hibernate web application?

Question

We have an web application that uses Spring-Hibernate to persist registered users data in Oracle database. The application works fine in development environment, but when we

Answer 1

Visual GC, now part of JDK 6, gives a very nice graphical representation of memory in real time. You can see what's happening to eden, generational, and perm spaces. You just won't see why.

UPDATE: It's bin/jvisualvm.exe in my JDK 1.6.0_13 distro. Give it the PID of the process you want to monitor.