Return-Path: 
 <dev-return-26206-apmail-activemq-dev-archive=activemq.apache.org@activemq.apache.org>
Delivered-To: apmail-activemq-dev-archive@www.apache.org
Received: (qmail 19562 invoked from network); 8 Apr 2011 16:22:45 -0000
Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3)
  by minotaur.apache.org with SMTP; 8 Apr 2011 16:22:45 -0000
Received: (qmail 77430 invoked by uid 500); 8 Apr 2011 16:22:45 -0000
Delivered-To: apmail-activemq-dev-archive@activemq.apache.org
Received: (qmail 77397 invoked by uid 500); 8 Apr 2011 16:22:45 -0000
Mailing-List: contact dev-help@activemq.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:dev-help@activemq.apache.org>
List-Unsubscribe: <mailto:dev-unsubscribe@activemq.apache.org>
List-Post: <mailto:dev@activemq.apache.org>
List-Id: <dev.activemq.apache.org>
Reply-To: dev@activemq.apache.org
Delivered-To: mailing list dev@activemq.apache.org
Received: (qmail 77389 invoked by uid 99); 8 Apr 2011 16:22:45 -0000
Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136)
    by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 08 Apr 2011 16:22:45 +0000
X-ASF-Spam-Status: No, hits=-2000.0 required=5.0
	tests=ALL_TRUSTED,T_RP_MATCHES_RCVD
X-Spam-Check-By: apache.org
Received: from [140.211.11.116] (HELO hel.zones.apache.org) (140.211.11.116)
    by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 08 Apr 2011 16:22:43 +0000
Received: from hel.zones.apache.org (hel.zones.apache.org [140.211.11.116])
	by hel.zones.apache.org (Postfix) with ESMTP id D47AF98868
	for <dev@activemq.apache.org>; Fri,  8 Apr 2011 16:22:06 +0000 (UTC)
Date: Fri, 8 Apr 2011 16:22:06 +0000 (UTC)
From: "Gary Tully (JIRA)" <jira@apache.org>
To: dev@activemq.apache.org
Message-ID: 
 <1383881155.44061.1302279726867.JavaMail.tomcat@hel.zones.apache.org>
In-Reply-To: 
 <1770125323.43800.1302270545667.JavaMail.tomcat@hel.zones.apache.org>
Subject: [jira] [Resolved] (AMQ-3276) ConcurrentModificationException in
 embedded 5.5.0 broker
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394


     [ https://issues.apache.org/jira/browse/AMQ-3276?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Gary Tully resolved AMQ-3276.
-----------------------------

       Resolution: Fixed
    Fix Version/s: 5.6.0
         Assignee: Gary Tully

reverted the explicit copy/set of the MDC context on thread creation as the underlying mdc impl used an inherited thread local for the context which makes the copy unnecessary and can cause contention. 
the changes in http://svn.apache.org/viewvc?view=revision&revision=1090320 should resolve the concurrent mod exception. I kicked off a new 5.6-SNAPSHOT deploy so if you get a chance please validate.

> ConcurrentModificationException in embedded 5.5.0 broker
> --------------------------------------------------------
>
>                 Key: AMQ-3276
>                 URL: https://issues.apache.org/jira/browse/AMQ-3276
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Broker
>    Affects Versions: 5.5.0
>         Environment: jdk 1.6.0_24, Spring 3.0.5, ActiveMQ 5.5.0, Camel 2.7.0, slf4j 1.6.1
>            Reporter: Dan Checkoway
>            Assignee: Gary Tully
>             Fix For: 5.6.0
>
>
> We just migrated from ActiveMQ 5.4.2 to ActiveMQ 5.5.0.  So far so good, with one exception (pun not intended).  In one case where we have an embedded broker, we're seeing this exception get logged on occasion:
> WARNING; 08-Apr-2011 11:11:41; tid:45931; TransportConnection stopAsync; cannot create async transport stopper thread.. not waiting for stop to complete, reason:
> java.util.ConcurrentModificationException
>         at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
>         at java.util.HashMap$EntryIterator.next(HashMap.java:834)
>         at java.util.HashMap$EntryIterator.next(HashMap.java:832)
>         at java.util.HashMap.putAllForCreate(HashMap.java:435)
>         at java.util.HashMap.<init>(HashMap.java:225)
>         at org.slf4j.helpers.BasicMDCAdapter.getCopyOfContextMap(BasicMDCAdapter.java:130)
>         at org.slf4j.MDC.getCopyOfContextMap(MDC.java:182)
>         at org.apache.activemq.util.MDCHelper.getCopyOfContextMap(MDCHelper.java:30)
>         at org.apache.activemq.broker.TransportConnection.stopAsync(TransportConnection.java:946)
>         at org.apache.activemq.broker.TransportConnection.processShutdown(TransportConnection.java:353)
>         at org.apache.activemq.command.ShutdownInfo.visit(ShutdownInfo.java:35)
>         at org.apache.activemq.broker.TransportConnection.service(TransportConnection.java:306)
>         at org.apache.activemq.broker.TransportConnection$1.onCommand(TransportConnection.java:179)
>         at org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116)
>         at org.apache.activemq.transport.TransportFilter.onCommand(TransportFilter.java:69)
>         at org.apache.activemq.transport.vm.VMTransport.iterate(VMTransport.java:218)
>         at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:127)
>         at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>         at java.lang.Thread.run(Thread.java:662)
> Up until this morning, I had only seen that logged during shutdown of the app context.  But just now, it popped out independently, out of the blue.
> For what it's worth, here's the app context config:
>  
>   <broker xmlns="http://activemq.apache.org/schema/core"
>           id="embeddedActivemqBroker"
>           useJmx="true"
>           persistent="true"
>           schedulerSupport="false"
>           advisorySupport="false"
>           enableStatistics="true">
>     <destinationPolicy>
>       <policyMap>
>         <policyEntries>
>           <policyEntry queue=">" producerFlowControl="false" memoryLimit="20mb"/>
>         </policyEntries>
>       </policyMap>
>     </destinationPolicy>
>     <persistenceAdapter>
>       <kahaDB directory="${EmbeddedBroker.dataDirectory}"
>               concurrentStoreAndDispatchQueues="false"/>
>     </persistenceAdapter>
>   </broker>
> Has anybody else seen this ConcurrentModificationException happening with 5.5.0 (or otherwise)?  Any ideas?
> I suppose I should also mention that we're using slf4j 1.6.1.  Not sure if that has anything to do with this, since the stack trace does show it happening in slf4j land...
>     <dependency>
>       <groupId>org.slf4j</groupId>
>       <artifactId>slf4j-api</artifactId>
>       <version>1.6.1</version>
>       <scope>runtime</scope>
>     </dependency>
>     <dependency>
>       <groupId>org.slf4j</groupId>
>       <artifactId>slf4j-jdk14</artifactId>
>       <version>1.6.1</version>
>       <scope>runtime</scope>
>     </dependency> 

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira