[CAMEL-9994] Deadlock in Failover Loadbalancer

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.15.3, 2.16.1, 2.17.1
• Fix Version/s: 2.17.2, 2.18.0
• Component/s: camel-core
• Labels: failover jms loadbalancer

Environment

Mac OSX + ActiveMQ, Solaris + MQ

• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Lee Kong
• Created: 26/May/16 11:45
• Updated: 23/Aug/16 14:32
• Resolved: 29/May/16 09:39

Description

Calling the route below with 2 threads simultaneously, when the messages timeout, I get a deadlock. The issue seems to be with CorrelationTimeoutMap.onEviction() where a thread is trying to acquire a lock while holding another lock (another thread tries to do the same).

I have created a simple project to demonstrate the issue:
https://github.com/leechinkong/CamelFailoverLoadbalancer

from("direct:test")
.loadBalance()
.failover(3, true, true)
.inOut("jms:testRqQueue1?replyTo=testRsQueue1&useMessageIDAsCorrelationID=true","jms:testRqQueue2?replyTo=testRsQueue2&useMessageIDAsCorrelationID=true");

Thread dump:

"Camel (camel-1) thread #0 - JmsReplyManagerTimeoutChecker[testRsQueue1]":
at sun.misc.Unsafe.park(Native Method)

• parking to wait for <0x00000007aca28f60> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
  at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
  at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:214)
  at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:290)
  at org.apache.camel.support.DefaultTimeoutMap.putIfAbsent(DefaultTimeoutMap.java:116)
  at org.apache.camel.component.jms.reply.CorrelationTimeoutMap.putIfAbsent(CorrelationTimeoutMap.java:108)
  at org.apache.camel.component.jms.reply.ReplyManagerSupport.registerReply(ReplyManagerSupport.java:105)
  at org.apache.camel.component.jms.JmsProducer$1.createMessage(JmsProducer.java:227)
  at org.apache.camel.component.jms.JmsConfiguration$CamelJmsTemplate.doSendToDestination(JmsConfiguration.java:282)
  at org.apache.camel.component.jms.JmsConfiguration$CamelJmsTemplate.access$100(JmsConfiguration.java:225)
  at org.apache.camel.component.jms.JmsConfiguration$CamelJmsTemplate$1.doInJms(JmsConfiguration.java:239)
  at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:493)
  at org.apache.camel.component.jms.JmsConfiguration$CamelJmsTemplate.send(JmsConfiguration.java:236)
  at org.apache.camel.component.jms.JmsProducer.doSend(JmsProducer.java:409)
  at org.apache.camel.component.jms.JmsProducer.processInOut(JmsProducer.java:239)
  at org.apache.camel.component.jms.JmsProducer.process(JmsProducer.java:150)
  at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:129)
  at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
  at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:91)
  at org.apache.camel.builder.NoErrorHandlerBuilder$1.process(NoErrorHandlerBuilder.java:40)
  at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
  at org.apache.camel.processor.Pipeline.process(Pipeline.java:118)
  at org.apache.camel.processor.Pipeline.process(Pipeline.java:80)
  at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
  at org.apache.camel.component.direct.DirectProducer.process(DirectProducer.java:51)
  at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:129)
  at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
  at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
  at org.apache.camel.processor.FatalFallbackErrorHandler.process(FatalFallbackErrorHandler.java:49)
  at org.apache.camel.processor.RedeliveryErrorHandler.deliverToFailureProcessor(RedeliveryErrorHandler.java:896)
  at org.apache.camel.processor.RedeliveryErrorHandler.processAsyncErrorHandler(RedeliveryErrorHandler.java:561)
  at org.apache.camel.processor.RedeliveryErrorHandler$1.done(RedeliveryErrorHandler.java:466)
  at org.apache.camel.management.InstrumentationProcessor$1.done(InstrumentationProcessor.java:86)
  at org.apache.camel.processor.SendProcessor$1.done(SendProcessor.java:139)
  at org.apache.camel.processor.CamelInternalProcessor$InternalCallback.done(CamelInternalProcessor.java:250)
  at org.apache.camel.processor.Pipeline$1.done(Pipeline.java:145)
  at org.apache.camel.processor.CamelInternalProcessor$InternalCallback.done(CamelInternalProcessor.java:250)
  at org.apache.camel.builder.NoErrorHandlerBuilder$1$1.done(NoErrorHandlerBuilder.java:44)
  at org.apache.camel.management.InstrumentationProcessor$1.done(InstrumentationProcessor.java:86)
  at org.apache.camel.processor.SendProcessor$1.done(SendProcessor.java:139)
  at org.apache.camel.component.jms.reply.ReplyManagerSupport.processReply(ReplyManagerSupport.java:179)
  at org.apache.camel.component.jms.reply.TemporaryQueueReplyHandler.onTimeout(TemporaryQueueReplyHandler.java:61)
  at org.apache.camel.component.jms.reply.CorrelationTimeoutMap.onEviction(CorrelationTimeoutMap.java:54)
  at org.apache.camel.component.jms.reply.CorrelationTimeoutMap.onEviction(CorrelationTimeoutMap.java:30)
  at org.apache.camel.support.DefaultTimeoutMap.purge(DefaultTimeoutMap.java:230)
  at org.apache.camel.support.DefaultTimeoutMap.run(DefaultTimeoutMap.java:180)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at java.lang.Thread.run(Thread.java:745)

Found 1 deadlock.

Issue Links

• depends upon: CAMEL-6439 camel-jms - Add thread pool for handling timeout when doing request/reply and allow to configure this thread pool