As I'm sure you know, ADF introduces some additional scopes (pageFlowScope, viewScope and backingBeanScope) on top of the standard JSF ones. Our use of one of the ADF scopes, viewScope, appears to be causing our session size to bloat over time.
Objects that are view scoped (e.g. our Backing Beans) are managed by ADF and appear to be put into the session in a org.apache.myfaces.trinidadinternal.application.StateManagerImpl$PageState object. The number of these objects in the session is equal to the org.apache.myfaces.trinidad.CLIENT_STATE_MAX_TOKENS in our web.xml configuration file.
Once all of the tokens are ‘used up’, by navigating around the application, the oldest one of these objects is removed from the session and (should be) garbage collected at some point. However, the reclaim of this space is observed much later, after the session has expired. Because of this, when load testing the application we see the heap space usage gradually increasing, before causing the JVM to crash.
The monitoring of the creation and destruction of our objects is done by adding log statements in the default constructor and in the finalize method (Which overrides the finalize method on object). The logging statements on object creation are seen when we would expect them, but the logging statements from the finalize method are only seen after session expiry. When a garbage collection is triggered using Oracle JRocket Mission Control we see the heap usage drop significantly, but don’t observe any logging from the finalize method calls.
Does anyone have any thoughts on why the garbage collector might not be able to reclaim view scoped objects after they are removed from the session?
Thanks in advance.
P.S. I have already found
2367488 which is a very closesly related thread, but unfortunately was not able to use the replies on there to resolve our issue. I've also posted this same question on Stack Overflow (http://stackoverflow.com/questions/13380151/lifetime-of-view-scoped-objects-oracle-adf). I'll try and update both threads if I find a solution.
Edited by: 971217 on 14-Nov-2012 07:08