"Failed to reinstate timer" warning is shown when creating large number of EJB timers

Hi, manovotn,

as we discussed before, I am creating a JIRA for an issue I experienced when testing EJB Timers with jBPM.

What I did was that I started a large number of processes with jBPM, let's say 10 000 and more. Each process contains a timer which jBPM will create an EJB Timer for. Each timer was configured to fire at exactly the same time, e.g. 12:00 PM. During the test I got this warning displayed about 5 times for each 10 000 timers created:

WARN  [org.jboss.as.ejb3] (Timer-1) WFLYEJB0161: Failed to reinstate timer 'kie-server.kie-server.EJBTimerScheduler' (id=09afab21-6b0f-41b0-9338-403b4a12e507) from its persistent state: java.lang.IllegalStateException: WFLYCTL0075: Duplicate resource 09afab21-6b0f-41b0-9338-403b4a12e507
    at org.jboss.as.controller.registry.AbstractModelResource$DefaultResourceProvider.register(AbstractModelResource.java:290)
    at org.jboss.as.controller.registry.AbstractModelResource.registerChild(AbstractModelResource.java:169)
    at org.jboss.as.ejb3.subsystem.deployment.TimerServiceResource.timerCreated(TimerServiceResource.java:193)
    at org.jboss.as.ejb3.timerservice.TimerServiceImpl.registerTimerResource(TimerServiceImpl.java:1094)
    at org.jboss.as.ejb3.timerservice.TimerServiceImpl.startTimer(TimerServiceImpl.java:767)
    at org.jboss.as.ejb3.timerservice.TimerServiceImpl$TimerRefreshListener.timerAdded(TimerServiceImpl.java:1235)
    at org.jboss.as.ejb3.timerservice.persistence.database.DatabaseTimerPersistence$RefreshTask.run(DatabaseTimerPersistence.java:820)
    at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)

The result of these warnings was that when I had only one EAP instance to fire these timers, it wouldn't fire exactly the timers with ids that were in those warnings, e.g. if it was id=09afab21-6b0f-41b0-9338-403b4a12e507 then this timer wouldn't fire. I had waited for minutes to be sure there is another tick of a refresh interval (configured to 1 min) but nothing happened. But when I started the second EAP instance, they were immediately picked up by that instance and fired. It seems that if there is this warning on a particular instance, the instance won't pick up the timer whatsoever. They will be picked up only by some other instances if there are any. With 2 EAP instances there were warnings too, but all timers fired since I guess affected timers were picked up each time by the other instance.

Another interesting observation is that when I configured a refresh interval to be shorter, e.g. 5 seconds, these warnings were showing up almost every 5 seconds. When I set it to 30 minutes, I didn't get warnings at all, since all timers fired earlier than a refresh occurred.

So I think it has something to do with refresh interval.

Can you please have a look at it? For further configuration details, check the Environment field.

Thank you very much!

Marian Macik