Dears,

Could you please help me understand this exception in logs, which seem to be related to operators. And how to prevent it. We are using Pega 7.3.1

[6/15/18 13:49:24:387 CEST] 000003eb EventService W Exception thrown by;EventService subscriber:com.pega.pegarules.session.internal.presence.PresenceStandardLifeCycleListener@497d20b2. Subscriber class:class com.pega.pegarules.session.internal.presence.PresenceStandardLifeCycleListener
com.pega.bushe.exception.SwingException: com.pega.pegarules.session.external.presence.PresenceLifeCycleEvent, event=com.pega.pegarules.session.external.presence.PresenceLifeCycleEvent@8d327d7, topic=null, eventObj=null
com.pega.bushe.exception.SwingException: com.pega.pegarules.session.external.presence.PresenceLifeCycleEvent, event=com.pega.pegarules.session.external.presence.PresenceLifeCycleEvent@8d327d7, topic=null, eventObj=null
at com.pega.bushe.event.ThreadSafeEventService.handleException(ThreadSafeEventService.java:1307)
at com.pega.bushe.event.ThreadSafeEventService.handleException(ThreadSafeEventService.java:1299)
at com.pega.bushe.event.ThreadSafeEventService.publish(ThreadSafeEventService.java:633)
at com.pega.bushe.event.ThreadSafeEventService.publish(ThreadSafeEventService.java:540)
at com.pega.bushe.event.EventBus.publish(EventBus.java:60)
at com.pega.pegarules.session.internal.mgmt.base.RequestorPassivation.notifyPresence(RequestorPassivation.java:685)
at com.pega.pegarules.session.internal.mgmt.base.RequestorPassivation.cleanupImpl(RequestorPassivation.java:652)
at com.pega.pegarules.session.internal.mgmt.PRRequestorBase.cleanup(PRRequestorBase.java:876)
at com.pega.pegarules.session.internal.mgmt.PRRequestorImpl.cleanup(PRRequestorImpl.java:389)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.cleanupConditionally(NodeRequestorMgt.java:1396)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.cleanupInner(NodeRequestorMgt.java:1318)
at sun.reflect.GeneratedMethodAccessor202.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
at java.lang.reflect.Method.invoke(Method.java:508)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1338)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1075)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:930)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.cleanupRequestor(NodeRequestorMgt.java:1294)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.cleanupRequestor(NodeRequestorMgt.java:1288)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.timeoutRequestorThrowingErrors(NodeRequestorMgt.java:1271)
at com.pega.pegarules.session.internal.mgmt.base.NodeRequestorMgt.processPassivationQueue(NodeRequestorMgt.java:2717)
at com.pega.pegarules.session.internal.async.PassivationDaemon.processPassivationQueue(PassivationDaemon.java:365)
at com.pega.pegarules.session.internal.async.PassivationDaemon.run(PassivationDaemon.java:339)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1327)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1075)
at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:884)
at com.pega.pegarules.session.internal.async.PassivationDaemon.run(PassivationDaemon.java:301)
at com.pega.pegarules.session.internal.engineinterface.etier.impl.AsyncServant.processAsyncTask(AsyncServant.java:283)
at com.pega.pegarules.session.internal.engineinterface.etier.impl.AsyncServant.invoke(AsyncServant.java:171)
at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl._invokeEngine_privact(EngineImpl.java:331)
at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl.invokeEngine(EngineImpl.java:274)
at com.pega.pegarules.session.internal.engineinterface.etier.ejb.EngineBean.invokeEngine(EngineBean.java:225)
at sun.reflect.GeneratedMethodAccessor152.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
at java.lang.reflect.Method.invoke(Method.java:508)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:367)
at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:408)
at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingThrowable(AppServerBridgeToPega.java:223)
at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingException(AppServerBridgeToPega.java:245)
at com.pega.pegarules.internal.etier.ejb.EngineBeanBoot.invokeEngine(EngineBeanBoot.java:168)
at com.pega.pegarules.internal.etier.interfaces.EJSLocalStatelessEngineBMT_f2439d86.invokeEngine(Unknown Source)
at com.pega.pegarules.session.internal.engineinterface.etier.mdb.PRAsync.processRequest(PRAsync.java:155)
at com.pega.pegarules.session.internal.engineinterface.etier.asynchbeans.AsyncTask.run(AsyncTask.java:64)
at com.pega.pegarules.session.internal.engineinterface.etier.asynchbeans.RunnableWrapper.run(RunnableWrapper.java:71)
at com.ibm.ws.asynchbeans.J2EEContext$RunProxy.run(J2EEContext.java:271)
at java.security.AccessController.doPrivileged(AccessController.java:594)
at com.ibm.ws.asynchbeans.J2EEContext.run(J2EEContext.java:797)
at com.ibm.ws.asynchbeans.WorkWithExecutionContextImpl.go(WorkWithExecutionContextImpl.java:222)
at com.ibm.ws.asynchbeans.ABWorkItemImpl.run(ABWorkItemImpl.java:206)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1892)
Caused by: com.pega.pegarules.priv.presence.PresenceRuntimeException: presence record resulted a size of zero or null for operator id844508, tenantHash: shared, requestorId: HUB43HKLIFOLKLMZKYLQDPPT9WFG7M7T9
at com.pega.pegarules.session.internal.presence.processors.PresenceDistUpdateSessionProcessor.process(PresenceDistUpdateSessionProcessor.java:52)
at com.pega.pegarules.cluster.internal.presence.PresenceDataGridHazelcast.replace(PresenceDataGridHazelcast.java:186)
at com.pega.pegarules.session.internal.presence.PresenceDataProcessorImpl.updateSession(PresenceDataProcessorImpl.java:216)
at com.pega.pegarules.session.internal.presence.PresenceLifeCycleEventManager.updateSession(PresenceLifeCycleEventManager.java:223)
at com.pega.pegarules.session.internal.presence.PresenceStandardLifeCycleListener.onEvent(PresenceStandardLifeCycleListener.java:54)
at com.pega.bushe.event.ThreadSafeEventService.publish(ThreadSafeEventService.java:629)
... 47 more