thread safety issue with Exchange.getUnitOfWork()
-------------------------------------------------
Key: CAMEL-4447
URL: https://issues.apache.org/jira/browse/CAMEL-4447
Project: Camel
Issue Type: Bug
Components: camel-core
Affects Versions: 2.8.1
Environment: JDK 1.6.0_20 on Linux x86_64
Reporter: David Tombs
I'm having a somewhat rare issue with NullPointerExceptions in a multithreaded
route. It seems that there is a race condition between one thread operating on
the UnitOfWork and another removing it. I have gotten the following stacktraces
so far:
{{
ERROR [Camel0 - Resequencer Delivery] o.a.c.p.StreamResequencer - Caused by:
[java.lang.NullPointerException - null]
java.lang.NullPointerException: null
at
org.apache.camel.processor.DefaultChannel$1.done(DefaultChannel.java:309)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.RedeliveryErrorHandler.processErrorHandler(RedeliveryErrorHandler.java:349)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:209)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.DefaultChannel.process(DefaultChannel.java:305)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:78)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:116)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:79)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:104)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:59)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer.sendElement(StreamResequencer.java:165)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer.sendElement(StreamResequencer.java:61)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.resequencer.ResequencerEngine.deliverNext(ResequencerEngine.java:254)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.resequencer.ResequencerEngine.deliver(ResequencerEngine.java:218)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer$Delivery.run(StreamResequencer.java:212)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
}}
And:
{{
ERROR [Camel0 - Resequencer Delivery] o.a.c.p.StreamResequencer - Caused by:
[java.lang.NullPointerException - null]
java.lang.NullPointerException: null
at
org.apache.camel.impl.DefaultExchange.isTransacted(DefaultExchange.java:331)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:57)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:116)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:79)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:104)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at org.apache.camel.processor.Pipeline.process(Pipeline.java:59)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer.sendElement(StreamResequencer.java:165)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer.sendElement(StreamResequencer.java:61)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.resequencer.ResequencerEngine.deliverNext(ResequencerEngine.java:254)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.resequencer.ResequencerEngine.deliver(ResequencerEngine.java:218)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
at
org.apache.camel.processor.StreamResequencer$Delivery.run(StreamResequencer.java:212)
~[camel-core-2.8.1-SNAPSHOT.jar:2.8.1-SNAPSHOT]
}}
Looking at the source, both NullPointerExceptions were thrown by code like:
{{
return getUnitOfWork() != null && getUnitOfWork().isTransacted();
}}
Oddly, I've only seen this happen soon after startup and only once per run.
The actual route is company confidential, but it's basically:
JMS -> Stream Resequencer -> Bean
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
