Here is my flow:
Queue A has a store limit set to 15% and producerFlowControl turned on.
Thread "foo" publishes on queue A
Thread "bar" listens for A, does something, and publishes on queue B
Thread "bat" listens for B, does something and publishes on queue C
Thread "boo" listens for C, does something and only ocassionally publishes on A
Store reaches 15%.
Foo gets stopped, rightfully so.
The whole thing is now blocked. Using Jconsole:
foo is blocked on this:
Stack trace:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:156)
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1987)
java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:315)
org.apache.activemq.transport.FutureResponse.getResult(FutureResponse.java:40)
org.apache.activemq.transport.ResponseCorrelator.request(ResponseCorrelator.java:87)
org.apache.activemq.ActiveMQConnection.syncSendPacket(ActiveMQConnection.java:1284)
org.apache.activemq.ActiveMQSession.send(ActiveMQSession.java:1760)
- locked java.lang.Object@407f434d
org.apache.activemq.ActiveMQMessageProducer.send(ActiveMQMessageProducer.java:231)
org.apache.activemq.ActiveMQMessageProducerSupport.send(ActiveMQMessageProducerSupport.java:241)
bar is now blocked on this as well it seems waiting for foo to free up
this lock:
Stack trace:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:156)
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1987)
java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:315)
org.apache.activemq.transport.FutureResponse.getResult(FutureResponse.java:40)
org.apache.activemq.transport.ResponseCorrelator.request(ResponseCorrelator.java:87)
org.apache.activemq.ActiveMQConnection.syncSendPacket(ActiveMQConnection.java:1284)
org.apache.activemq.ActiveMQSession.send(ActiveMQSession.java:1760)
- locked java.lang.Object@202ed609
org.apache.activemq.ActiveMQMessageProducer.send(ActiveMQMessageProducer.java:231)
org.apache.activemq.ActiveMQMessageProducerSupport.send(ActiveMQMessageProducerSupport.java:241)
and boo is blocked trying to send it back to queue A, as expected.
So, store is not getting freed up.
Why ? This has got to be a misconfiguration...
--
Regards,
Oleg Dulin
NYC Java Big Data Engineer
http://www.olegdulin.com/
