PermGen space
There are many "solutions" to this issue many involving garbage collection parameters and increasing memory limits. The main cause is a fault in the application code, or the libraries that that code depends on and the issue can not be simply resolved by using garbage collection flag. The issue can be delayed by raising memory limits but that is only a temoporary solution. The only imediate resolution is found in restarting the JVM instance responsible for the application server. The following further explains the issue and explains the tools needed to track down the class loader leak(s):
Understanding the Issue
Classloader leaks: the dreaded "java.lang.OutOfMemoryError: PermGen space" exception
How to fix the dreaded "java.lang.OutOfMemoryError: PermGen space" exception (classloader leaks)
Fixing The Issue - Specific Solutions and Tests
[work in progress]