What is the Meaning of ERROR: [ERROR] [ClusterManager Async Executor] [Manager] Uncaught Exception in Enterprise Manager: In thread 'ClusterManager Async Executor' and the message is: java.lang.NullPointerException java.lang.NullPointerException

Products

• CA Application Performance Management (APM / Wily / Introscope)

Issue/Introduction

Below error message found at the time when there was performance issue  at em cluster where as perflog is showing no issue . What is the meaning of the below error message and is it related to performance ? if so how to fix that ? 

[ERROR]:

*************

[ClusterManager Async Executor] [Manager] Uncaught Exception in Enterprise Manager: In thread 'ClusterManager Async Executor' and the message is: java.lang.NullPointerException
java.lang.NullPointerException
    at com.wily.introscope.console.thornhill.manager.AGizmoTrackingManager.untrackGizmo(AGizmoTrackingManager.java:508)
    at com.wily.introscope.console.thornhill.manager.AGizmoTrackingManager.noticeRemoteGizmoDisappearance(AGizmoTrackingManager.java:655)
    at com.wily.introscope.console.thornhill.manager.agent.AgentManager.noticeRemoteGizmoDisappearance(AgentManager.java:663)
    at com.wily.introscope.console.thornhill.manager.agent.AgentManager$AgentNotificationAdapter.agentsRemoved(AgentManager.java:356)
    at com.wily.introscope.spec.server.beans.agentservice.AgentNotification.dataRemoved(AgentNotification.java:54)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager$NotifyRemoved.run(AbstractQueryServiceManager.java:573)
    at com.wily.isengard.ongoingquery.QueryServiceManager2$1.execute(QueryServiceManager2.java:46)
    at com.wily.isengard.ongoingquery.QueryServiceManager2.runNotification(QueryServiceManager2.java:85)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager$3.run(AbstractQueryServiceManager.java:342)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.runTask(AbstractQueryServiceManager.java:284)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.stateRemoved(AbstractQueryServiceManager.java:356)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.stateRemoved(AbstractQueryServiceManager.java:310)
    at com.wily.introscope.server.beans.AOngoingQueriableBean.stateRemoved(AOngoingQueriableBean.java:106)
    at com.wily.introscope.server.beans.agentservice.internal.ClusteredAgentService.removeAgentsForCollectors(ClusteredAgentService.java:866)
    at com.wily.introscope.server.beans.agentservice.internal.ClusteredAgentService.collectorsRemoved(ClusteredAgentService.java:836)
    at com.wily.introscope.spec.server.beans.clusters.ClusterNotification.dataRemoved(ClusterNotification.java:28)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager$NotifyRemoved.run(AbstractQueryServiceManager.java:573)
    at com.wily.isengard.ongoingquery.QueryServiceManager2$1.execute(QueryServiceManager2.java:46)
    at com.wily.isengard.ongoingquery.QueryServiceManager2.runNotification(QueryServiceManager2.java:85)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager$3.run(AbstractQueryServiceManager.java:342)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.runTask(AbstractQueryServiceManager.java:284)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.stateRemoved(AbstractQueryServiceManager.java:356)
    at com.wily.isengard.ongoingquery.AbstractQueryServiceManager.stateRemoved(AbstractQueryServiceManager.java:310)
    at com.wily.introscope.server.beans.AOngoingQueriableBean.stateRemoved(AOngoingQueriableBean.java:106)
    at com.wily.introscope.server.beans.clusters.ClusterManager.collectorRemoved(ClusterManager.java:287)
    at com.wily.introscope.server.beans.clusters.ClusterManager.access$1(ClusterManager.java:271)
    at com.wily.introscope.server.beans.clusters.ClusterManager$CollectorRemovedCommand.run(ClusterManager.java:386)
    at com.wily.EDU.oswego.cs.dl.util.concurrent.QueuedExecutor$RunLoop.run(QueuedExecutor.java:88)
    at java.lang.Thread.run(Thread.java:745)

Environment

10.8 SAP

Resolution

Looking at the call stack, the NullPointerException occurred upon notifying workstation to clean up UI display as needed when having agent disconnections with collector.  If the customer observed this error while having EM cluster performance issues, it could indicate the notification queue somewhat getting out of sync at the moment.  The message was from ClusterManager Async Executor and likely not very critical to have a timely response.

So Basically , could be the side effect from the performance issue, but didn't appear to be the one trigger the performance issue.