EHC ❯ ConcurrentModificationException when sending notification

• Type: Bug
• Status: Closed
• Priority:
• Resolution: Fixed
• Component/s:
• Labels:

• Assignee: drb
• Reporter: sourceforgetracker
• Created: September 21, 2009
• Votes: 0
• Watchers: 0
• Updated:

  September 22, 2009
• Resolved:

  September 22, 2009

Description

I use JGroups to cluster EHCache, with invalidation instead of replication, and sometimes the following error is thrown from the JGroupsReplicator (version 1.2):

2009-04-29 22:25:52,194 ERROR [org.jgroups.blocks.NotificationBus] error sending notification java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) at java.util.HashMap$KeyIterator.next(HashMap.java:828) at java.util.HashSet.writeObject(HashSet.java:267) at sun.reflect.GeneratedMethodAccessor1125.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1461) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326) at java.util.ArrayList.writeObject(ArrayList.java:570) at sun.reflect.GeneratedMethodAccessor906.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1461) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326) at org.jgroups.util.Util.objectToByteBuffer(Util.java:341) at org.jgroups.blocks.NotificationBus.sendNotification(NotificationBus.java:152) at org.jgroups.blocks.NotificationBus.sendNotification(NotificationBus.java:140) at net.sf.ehcache.distribution.jgroups.JGroupManager.send(JGroupManager.java:245) at net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicator.flushReplicationQueue(JGroupsCacheReplicator.java:417) at net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicator.replicationThreadMain(JGroupsCacheReplicator.java:375) at net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicator.access$000(JGroupsCacheReplicator.java:46) at net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicator$ReplicationThread.run(JGroupsCacheReplicator.java:354)

Sourceforge Ticket ID: 2784207 - Opened By: deadoggelito - 30 Apr 2009 08:20 UTC

Comments

Sourceforge Tracker 2009-09-21

Hi, you appear to be reporting a JGroups bug.

Can you try ehcache-jgroupsreplication-1.3. The JGroups dep is upgraded to 2.6.8.GA.

Or simply upgrade yourself. I don’t think there are any API changes.

Or change to RMI replication. Comment by: gregluck - 8 May 2009 03:22 UTC

Fiona OShea 2009-09-22

Re-opening so that I can properly close out these issues and have correct Resolution status in Jira