anonymous wrote : which classloader was used to load the class? I don't know if this is what you meant.. but I never cared about the classLoader holding the class. Every time I had a class leakage was one of these three scenarios: - static field holding reference to class/classLoader/reflection - Class instance/ClassLoader instance being held in a Map - Class instance being held in a WeakHashMap value. (Values are not weak. Any circular reference between the key and a value will keep a leak) - Instance of an object referenced. - Stack Reference to object/class/classLoaders I never had any case where a classLoader instance is holding a reference to its child classLoaders. I never cared about this, because if all references are inside the same classLoader, the reference would be gone before getting to the duplicates. ah... and about EJB3 I guess Bill Burke fixed some of those references, but there might be still some leakage he needs to work on. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967578#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...