Hi, we are using jboss 404 with messaging 1.0.1.GA and EJB3 The queue in question is non persistent and does not grow, so the messages do get delivered and processed fast enough. We observe the heap growing with instances of TxState and ArrayLists which belong to TxState, see output of heap analyzer below. At that point in time there are 338134 instances of TxState. anonymous wrote : References by Type | | class org.jboss.jms.tx.TxState [0x5aa9a200] | | Referrers by Type | Class / Count | EDU.oswego.cs.dl.util.concurrent.ConcurrentHashMap$Entry / 337800 | org.jboss.jms.tx.TransactionRequest / 215 | | Referees by Type | Class / Count | java.util.ArrayList / 676268 best regards, Martin View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3984543#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...