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  1. ActiveMQ
  2. AMQ-1730

Bad use of Jms field JMSXDeliveryCount. Related to RedeliveryCount and message prefetch

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 5.0.0, 5.1.0
    • Fix Version/s: 5.3.0
    • Component/s: Broker
    • Labels:
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      Description

      JMSXDeliveryCount has to be incremented only on transactional delivery failure ( RuntimeException on processing message, ... ).

      JMSXDeliveryCount is actualy used in correlation with Message.java field: 'redeliveryCounter'.

      But RedeliveryCounter field is used to be incremented each time the message is preteched or sent to a consumer => It does not mean that message has been processed by business in transaction with a failure. It just has been prefetched by consumer ou subscriber.
      A 'not consumed message' can be give back to the broker when the consumer is closed by user, because it has been prefetched but not really consumed!

      It does not match the meaning of the JMS field JMSXDeliveryCount :
      "If a failure occurs within transactional processing then the JMSXDeliveryCount is incremented".

      JMSXDeliveryCount field only has to be incremented on rollback (isn't it? ). This is why Message.redeliveryCount can not be used. Or the behavour of field Message.redeliveryCount has to be changed.

      You can either :

      • create a new counter on message incremented only on rollback, or
      • modify classes : PrefetchSubscription.java and Queue.java to remove redeliveryCount increment and increment it only on rollback.
      • PrefetchSubscription.java:

      if (inAckRange) {
      // node.incrementRedeliveryCounter();
      if (ack.getLastMessageId().equals(messageId))

      { destination = node.getRegionDestination(); callDispatchMatched = true; break; }

      }

      • Queue.java:

      for (MessageReference ref : sub.remove(context, this)) {
      QueueMessageReference qmr = (QueueMessageReference)ref;
      // qmr.incrementRedeliveryCounter();
      if( qmr.getLockOwner()==sub ) {
      qmr.unlock();
      // if (!qmr.isDropped() && !qmr.isAcked())

      { // qmr.incrementRedeliveryCounter(); // }

      }
      list.add(qmr);
      }

      BTW, In this code it seems there is a second bug, in case of test "qmr.getLockOwner()==sub" is true qmr is incremented a second time ?! Is it right ?

      The result of this problem is the following:

      With Spring and DefaultMessageListenerContainer, a message is consumed one by one. This is why a message prefteched many times, on first real consuming has a JMSXDeliveryCount with high value not reflecting the reality.

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              • Assignee:
                gtully Gary Tully
                Reporter:
                alexiskinsella Alexis Kinsella
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                • Created:
                  Updated:
                  Resolved: