Here's the reference chain from the classloader back into JBossTS. There's a lot more besides this branching off from the com.arjuna.ats.arjuna.coordinator.TransactionReaper._list ref, but this is the gist of it. I can e-mail someone the full report if it's wanted. | !--org.jboss.mx.loading.UnifiedClassLoader3@1085eba{ url=null ,addedOrder=49} | !--!--ClassLoaderReference @ class $Proxy80 | !--!--!--InstanceOfReference:ToString=ClassloaderLeakStatefulSession:eza31jqw-8 | !--!--!--!--FieldReference UndefinedField@org.jboss.ejb.StatefulSessionEnterpriseContext@13ba312=org.jboss.ejb.StatefulSessionEnterpriseContext(a)13ba312 | !--!--!--!--!--FieldReference private org.jboss.ejb.EnterpriseContext org.jboss.ejb.plugins.StatefulSessionInstanceInterceptor$InstanceSynchronization.ctx=org.jboss.ejb.plugins.StatefulSessionInstanceInterceptor$InstanceSynchronization@122be0b | !--!--!--!--!--!--FieldReference private javax.transaction.Synchronization com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple._theSynch=com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple@ffa9d8 | !--!--!--!--!--!--!--FieldReference private com.arjuna.ats.arjuna.coordinator.SynchronizationRecord com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator._currentRecord=BasicAction: a0b0e66:58c:45f838a3:41 status: ActionStatus.COMMITTED | !--!--!--!--!--!--!--!--FieldReference public com.arjuna.ats.arjuna.coordinator.Reapable com.arjuna.ats.internal.arjuna.coordinator.ReaperElement._control=com.arjuna.ats.internal.arjuna.coordinator.ReaperElement@c47220 | !--!--!--!--!--!--!--!--!--FieldReference private final com.arjuna.ats.internal.arjuna.template.OrderedListElement com.arjuna.ats.internal.arjuna.template.OrderedListEntry._theElement=com.arjuna.ats.internal.arjuna.template.OrderedListEntry@16e2b70 | !--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.internal.arjuna.template.OrderedListEntry com.arjuna.ats.internal.arjuna.template.OrderedListEntry._next=com.arjuna.ats.internal.arjuna.template.OrderedListEntry@1e5d007 | !--!--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.internal.arjuna.template.OrderedListEntry com.arjuna.ats.internal.arjuna.template.OrderedListEntry._next=com.arjuna.ats.internal.arjuna.template.OrderedListEntry@bc8f01 | !--!--!--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.internal.arjuna.template.OrderedListEntry com.arjuna.ats.internal.arjuna.template.OrderedListEntry._next=com.arjuna.ats.internal.arjuna.template.OrderedListEntry@1509443 | !--!--!--!--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.internal.arjuna.template.OrderedListEntry com.arjuna.ats.internal.arjuna.template.OrderedList._headOfList=com.arjuna.ats.internal.arjuna.template.OrderedList@1c931fb | !--!--!--!--!--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.internal.arjuna.template.OrderedList com.arjuna.ats.arjuna.coordinator.TransactionReaper._list=com.arjuna.ats.arjuna.coordinator.TransactionReaper@126c885 | !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--Root | !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--Reference inside a method - com.arjuna.ats.internal.arjuna.coordinator.ReaperThread::run | !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--FieldReference private com.arjuna.ats.arjuna.coordinator.TransactionReaper com.arjuna.ats.internal.arjuna.coordinator.ReaperThread.reaperObject=Thread[Thread-23,5,jboss] | !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--Root | !--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--Reference inside a method - com.arjuna.ats.internal.arjuna.coordinator.ReaperThread::run All the stuff about Reapable and ReaperThread is what led me to think this wasn't a long-term leak in JBossTS. For more info on the test that produces this, see http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassloaderLeakUnitTestCase View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4028097#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...