<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi there,</div><div><br></div><div>If I understand correctly, you're creating the stateless knowledge session once and then providing access to execute it from multiple threads. That's not going to work too well … especially on 5.2. For each request using a stateless knowledge session you should call <span style="font-family: Monaco; font-size: 11px; color: rgb(3, 38, 204); ">kbase</span><span style="font-family: Monaco; font-size: 11px; ">.newStatelessKnowledgeSession()</span></div><div><br></div><div>i.e. Create the knowledge base once, but create a session for each request.</div><div><br></div><div>Steve</div><div><br></div><br><div><div>On 22 Jan 2013, at 15:14, nalvesp <<a href="mailto:npereira@cielo.com.br">npereira@cielo.com.br</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">I need some support with Drools. I'm using Drools 5.2 in a multi-threaded<br>environment. Basicaly, every login into a website is calling an execute<br>method in a StatelessKnowledgeSession. After some time, threads start to<br>lock as below:<br><br>"[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default<br>(self-tuning)'" id=18 idx=0xc0 tid=7267 prio=5 alive, in native, blocked,<br>daemon<br> -- Blocked trying to get lock:<br>org/drools/event/RuleBaseEventSupport@0x2aab52d6f518[fat lock]<br> at jrockit/vm/Threads.waitForUnblockSignal()V(Native Method)<br> at jrockit/vm/Locks.fatLockBlockOrSpin(Locks.java:1679)[optimized]<br> at jrockit/vm/Locks.lockFat(Locks.java:1780)[optimized]<br> at<br>jrockit/vm/Locks.monitorEnterSecondStageHard(Locks.java:1312)[optimized]<br> at jrockit/vm/Locks.monitorEnterSecondStage(Locks.java:1259)[optimized]<br> at<br>org/drools/event/AbstractEventSupport.addEventListener(AbstractEventSupport.java:65)[inlined]<br> at<br>org/drools/common/AbstractRuleBase.addEventListener(AbstractRuleBase.java:1018)[optimized]<br> at<br>org/drools/impl/KnowledgeBaseImpl.addEventListener(KnowledgeBaseImpl.java:127)[optimized]<br> at<br>org/jbpm/process/instance/ProcessRuntimeImpl.initProcessEventListeners(ProcessRuntimeImpl.java:201)<br> at<br>org/jbpm/process/instance/ProcessRuntimeImpl.<init>(ProcessRuntimeImpl.java:68)[optimized]<br> at<br>org/jbpm/process/instance/ProcessRuntimeFactoryServiceImpl.newProcessRuntime(ProcessRuntimeFactoryServiceImpl.java:10)<br> at<br>org/jbpm/process/instance/ProcessRuntimeFactoryServiceImpl.newProcessRuntime(ProcessRuntimeFactoryServiceImpl.java:6)<br> at<br>org/drools/runtime/process/ProcessRuntimeFactory.newProcessRuntime(ProcessRuntimeFactory.java:12)<br> at<br>org/drools/common/AbstractWorkingMemory.createProcessRuntime(AbstractWorkingMemory.java:359)[inlined]<br> at<br>org/drools/common/AbstractWorkingMemory.setKnowledgeRuntime(AbstractWorkingMemory.java:1260)[inlined]<br> at<br>org/drools/impl/StatefulKnowledgeSessionImpl.<init>(StatefulKnowledgeSessionImpl.java:116)[inlined]<br> at<br>org/drools/impl/StatelessKnowledgeSessionImpl.newWorkingMemory(StatelessKnowledgeSessionImpl.java:129)[inlined]<br> at<br>org/drools/impl/StatelessKnowledgeSessionImpl.execute(StatelessKnowledgeSessionImpl.java:293)[optimized]<br> at<br>br/com/cielo/engineRules/services/impl/CancelamentoRuleBean.validarRegrasCancelamento(CancelamentoRuleBean.java:79)[optimized]<br> at<br>br/com/cielo/engineRules/services/impl/CancelamentoRuleEJB_vyscvn_EOImpl.validarRegrasCancelamento(CancelamentoRuleEJB_vyscvn_EOImpl.java:205)[optimized]<br> at<br>br/com/cielo/engineRules/services/impl/CancelamentoRuleEJB_vyscvn_EOImpl_WLSkel.invoke(ILweblogic/rmi/spi/InboundRequest;Lweblogic/rmi/spi/OutboundResponse;Ljava/lang/Object;)Lweblogic/rmi/spi/OutboundResponse;(Unknown<br>Source)[optimized]<br> at<br>weblogic/rmi/internal/BasicServerRef.invoke(BasicServerRef.java:589)[optimized]<br> at<br>weblogic/rmi/cluster/ClusterableServerRef.invoke(ClusterableServerRef.java:230)[optimized]<br> at<br>weblogic/rmi/internal/BasicServerRef$1.run(BasicServerRef.java:477)[inlined]<br> at<br>weblogic/security/acl/internal/AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)[inlined]<br> at<br>weblogic/security/service/SecurityManager.runAs(Lweblogic/security/acl/internal/AuthenticatedSubject;Lweblogic/security/acl/internal/AuthenticatedSubject;Ljava/security/PrivilegedExceptionAction;)Ljava/lang/Object;(Unknown<br>Source)[inlined]<br> at<br>weblogic/rmi/internal/BasicServerRef.handleRequest(BasicServerRef.java:473)[inlined]<br> at<br>weblogic/rmi/internal/wls/WLSExecuteRequest.run(WLSExecuteRequest.java:118)[optimized]<br> at<br>weblogic/work/ExecuteThread.execute(ExecuteThread.java:201)[optimized]<br> at weblogic/work/ExecuteThread.run(ExecuteThread.java:173)<br> at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)<br> -- end of trace<br><br>I went to Drool's source code and there's a synchronized section right<br>before the lock. I'm afraid Drools doesn't support multi-thread processing.<br><br>Does anyone know anything about this issue???<br><br>Tks<br><br><br><br><br>--<br>View this message in context: <a href="http://drools.46999.n3.nabble.com/Drools-locking-threads-tp4021732.html">http://drools.46999.n3.nabble.com/Drools-locking-threads-tp4021732.html</a><br>Sent from the Drools: User forum mailing list archive at <a href="http://Nabble.com">Nabble.com</a>.<br>_______________________________________________<br>rules-users mailing list<br><a href="mailto:rules-users@lists.jboss.org">rules-users@lists.jboss.org</a><br>https://lists.jboss.org/mailman/listinfo/rules-users<br></blockquote></div><br></body></html>