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https://issues.apache.org/activemq/browse/AMQ-1120?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rob Davies reassigned AMQ-1120:
-------------------------------

    Assignee: Rob Davies

> Race Condition can result in hang on remoteBrokerNameKnownLatch
> ---------------------------------------------------------------
>
>                 Key: AMQ-1120
>                 URL: https://issues.apache.org/activemq/browse/AMQ-1120
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Transport
>    Affects Versions: 4.0, 4.0.1, 4.0.2
>         Environment: Windows XP, demand forwarding, failover == true
>            Reporter: Chris Hofstaedter
>            Assignee: Rob Davies
>             Fix For: 5.1.0
>
>
> My environment is comprised of Windows XP, AMQ v4.0.2, demand forwarding, 
> failover = true, client and broker are all within the same VM.  Typically, my 
> client and broker would not be within the same VM, but this issue was 
> encountered while executing my junit tests - not in a typical deployment 
> environment.
>  
> Basically, DemandForwardingBridgeSupport.startLocalBridge() hangs on 
> remoteBrokerNameKnownLatch.await();
>  
> It looks like the broker name becomes known prior to the call to await. I 
> think the response is coming in after the triggerLocalStartBridge thread is 
> spawned and the synchronized block in
> DemandForwardingBridgeSupport.startRemoteBridge() is exited but before the 
> await call in triggerLocalStartBridge.  
>  
> Like I said, I've only run into this when running demand forwarding with 
> client and broker in the same VM along with a high volume of messages sent 
> immediately after the connection is established, which for me, is an artifact 
> of junit testing.  
>  
> I have a relatively small number of clients that should connect fairly 
> infrequently, so I just put a bandaid of a 100ms wait into 
> TcpTransportServer.run right before getAcceptListener().onAccept() which 
> allows my tests to complete successfully and has no appreciable impact on the 
> performance I care about but it's obviously not a valid fix for the race 
> condition.

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