The test is processing xml documents. There is a servlet that is being fed one or more XML documents in every request. The servlet then creates a JMS message containing the document(s) and puts it on a queue. The MDB(s) listening on this queue is the controller. It sends a message corresponding to each step in the process to a different queue and there are MDBs that consume from each of the different queues. When the MDBs in each step is done with the message they send a message back to the control queue. The documents are normally 1K in size but occasionally can be larger or smaller than that. The first MDB is called the Dispatcher. It only is used if the request contained more than one document. It splits the request data into multiple documents and sends a message to the controller for each document. The second MDB is called the Master Processor. This is where each XML document is validated, compressed and persisted in the Sybase database. It sends a message to the controller after it is done. The third MDB is the Access Processor. This is where the XML document is converted to ASN.1 format and persisted in the Sybase database. All the queues are persistent. I tried setting the FullSize to 100 and the PageSize and DownCacheSize to 20 and the behavior is still the same. I keep getting a lot of errors as below and I am not sure why they are occuring and whether they have anything to do with the memory issue. ERROR [org.jboss.jms.client.container.ClosedInterceptor] ClosedInterceptor.ClientSessionDelegate[jr-i9awncff-1-q3osncff-g5axfp-2b2r6q3]: method createMapMessage() did not go through, the interceptor is CLOSED View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4145956#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...