ConcurrentModificationException

1
I get a ConcurrentModificationException in the log. It happens when importing master data (each object becomes a webservice call, so many calls in a short period of time). It happens approximately once every hour and lasts for 15 minutes. During that time, messages are handled, but after 15 minutes it starts working fine again (until 1 hour later). What can be the cause of this? Aug 11 14:18:46.751 127.0.0.1 tr10000: ERROR - ActorSystem: Unknown message: Failure(java.util.ConcurrentModificationException) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (1/13) com.mendix.systemwideinterfaces.MendixRuntimeException: Unknown message: Failure(java.util.ConcurrentModificationException) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (2/13) at com.mendix.core.session.ActionDispatcher$$anonfun$receive$2.applyOrElse(ActionDispatching.scala:132) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (3/13) at akka.actor.Actor$class.aroundReceive(Actor.scala:465) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (4/13) at com.mendix.core.session.ActionDispatcher.aroundReceive(ActionDispatching.scala:111) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (5/13) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (6/13) at akka.actor.ActorCell.invoke(ActorCell.scala:487) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (7/13) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (8/13) at akka.dispatch.Mailbox.run(Mailbox.scala:220) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (9/13) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (10/13) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (11/13) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (12/13) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) Aug 11 14:18:46.757 127.0.0.1 tr10000: ERROR - ActorSystem: (13/13) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
asked
4 answers
1

This is most likely caused by your process trying to use objects that another process is already using.

https://docs.oracle.com/javase/7/docs/api/java/util/ConcurrentModificationException.html

answered
1

This issue is caused by the Garbage Collector. It does not impact the actions itself (so no functional impact on the application). It's just that the garbage collection action fails at a certain point in time. It's highly unlikely that it would create a memory problem as the Garbage Collection action runs often and the next run most probably succeeds.

answered
0

Seems like a Mendix bug to me, I would file a ticket.

answered
0

The exact same thing here... Do you already know what is causing it?

Aug 30 14:13:41.497 127.0.0.1 tr10000: ERROR - ActorSystem: Unknown message: Failure(java.util.ConcurrentModificationException)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (1/13) com.mendix.systemwideinterfaces.MendixRuntimeException: Unknown message: Failure(java.util.ConcurrentModificationException)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (2/13)  at com.mendix.core.session.ActionDispatcher$$anonfun$receive$2.applyOrElse(ActionDispatching.scala:132)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (3/13)  at akka.actor.Actor$class.aroundReceive(Actor.scala:465)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (4/13)  at com.mendix.core.session.ActionDispatcher.aroundReceive(ActionDispatching.scala:111)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (5/13)  at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (6/13)  at akka.actor.ActorCell.invoke(ActorCell.scala:487)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (7/13)  at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (8/13)  at akka.dispatch.Mailbox.run(Mailbox.scala:220)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (9/13)  at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (10/13)     at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
Aug 30 14:13:41.501 127.0.0.1 tr10000: ERROR - ActorSystem: (11/13)     at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
Aug 30 14:13:41.502 127.0.0.1 tr10000: ERROR - ActorSystem: (12/13)     at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
Aug 30 14:13:41.502 127.0.0.1 tr10000: ERROR - ActorSystem: (13/13)     at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
answered