[AMQ-3887] Occasional Null Pointer Exception during NetworkConnector connection

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.6.0
• Fix Version/s: 5.7.0

Environment

SLES 10

• Assignee: Gary Tully
• Reporter: Ron Koerner
• Created: 18/Jun/12 16:02
• Updated: 21/Aug/12 11:26
• Resolved: 21/Aug/12 10:31

Description

While starting a duplex NetworkConnector an NPE can be observed on the receiving side.

2012-06-18 17:34:24,571 INFO  .DemandForwardingBridgeSupport - Network connection between vm://proxy-cbpi001#8 and tcp:///169.254.
0.5:59412(cbox-56BU101117) has been established. [StartLocalBridge: localBroker=vm://proxy-cbpi001#8]
2012-06-18 17:34:24,577 WARN  .DemandForwardingBridgeSupport - Caught an exception processing local command [BrokerService[proxy-c
bpi001] Task-19]
java.lang.NullPointerException: null
        at org.apache.activemq.network.DemandForwardingBridgeSupport.configureMessage(DemandForwardingBridgeSupport.java:644) ~[ac
tivemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.network.DemandForwardingBridgeSupport.serviceLocalCommand(DemandForwardingBridgeSupport.java:675) ~
[activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.network.DemandForwardingBridgeSupport$1.onCommand(DemandForwardingBridgeSupport.java:139) [activemq
-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.ResponseCorrelator.onCommand(ResponseCorrelator.java:116) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.MutexTransport.onCommand(MutexTransport.java:50) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.vm.VMTransport.doDispatch(VMTransport.java:135) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.vm.VMTransport.dispatch(VMTransport.java:124) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.vm.VMTransport.oneway(VMTransport.java:103) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:68) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.transport.ResponseCorrelator.oneway(ResponseCorrelator.java:60) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.broker.TransportConnection.dispatch(TransportConnection.java:1307) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.broker.TransportConnection.processDispatch(TransportConnection.java:837) [activemq-core-5.6.0.jar:5
.6.0]
        at org.apache.activemq.broker.TransportConnection.iterate(TransportConnection.java:872) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:122) [activemq-core-5.6.0.jar:5.6.0]
        at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:43) [activemq-core-5.6.0.jar:5.6.0]
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) [na:1.6.0_20]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.6.0_20]
        at java.lang.Thread.run(Unknown Source) [na:1.6.0_20]

The other broker will eventually connect, but with about a hundred of connecting brokers this occurs too often to ignore.

As this seems to be a race condition it is quite difficult to reproduce reliably. I assume producerInfo is accessed in configureMessage before it is initialized in startRemoteBridge.