I have discovered an issue with the latest activemq 5.0 (revision
581510) which seems to have been present for some time, at least for the
last month.
I have an application using transactions, and kaha persistence, and two
consumers feeding off a queue.
I sometimes see the same message being sent to two consumers. All
transactions were committed (no rollbacks), and as you can see by the
debug dump, the message has the same message-ID, but was delivered to
two separate consumers, running on separate threads, using sync receives
with a prefetch of 0, with separate sessions of course.
Is this a known problem? It doesn't always happen - seems to be a race
condition. If I turn off persistence, I don't seem to see it.
Here is the message being delivered to consumer 1:
2007-10-03 17:21:37,310 [Worker 060bacd87f4a40a4867113e2e3e553dd] 85475
DEBUG org.apache.activemq.ActiveMQMessageConsumer -
ID:tamarama-62436-1191396093006-2:2:3:2 received message:
MessageDispatch {commandId = 0, responseRequired = false, consumerId =
ID:tamarama-62436-1191396093006-2:2:3:2, destination =
queue://worker-items, message = ActiveMQObjectMessage {commandId = 50,
responseRequired = false, messageId =
ID:tamarama-62436-1191396093006-2:2:1:3:1, originalDestination = null,
originalTransactionId = null, producerId =
ID:tamarama-62436-1191396093006-2:2:1:3, destination =
queue://worker-items, transactionId =
TX:ID:tamarama-62436-1191396093006-2:2:5, expiration = 0, timestamp =
1191396097286, arrival = 0, brokerInTime = 1191396097290, brokerOutTime
= 1191396097303, correlationId = null, replyTo = null, persistent =
true, type = null, priority = 4, groupID = null, groupSequence = 0,
targetConsumerId = null, compressed = false, userID = null, content =
[EMAIL PROTECTED], marshalledProperties =
null, dataStructure = null, redeliveryCounter = 0, size = 0, properties
= null, readOnlyProperties = true, readOnlyBody = true, droppable =
false}, redeliveryCounter = 0}
Here is the same message (check the message ID) being delivered to
consumer 2:
2007-10-03 17:21:37,422 [Worker 2c3169d1726b4781a423a239f65c7bd1] 85587
DEBUG org.apache.activemq.ActiveMQMessageConsumer -
ID:tamarama-62436-1191396093006-2:2:1:2 received message:
MessageDispatch {commandId = 0, responseRequired = false, consumerId =
ID:tamarama-62436-1191396093006-2:2:1:2, destination =
queue://worker-items, message = ActiveMQObjectMessage {commandId = 50,
responseRequired = false, messageId =
ID:tamarama-62436-1191396093006-2:2:1:3:1, originalDestination = null,
originalTransactionId = null, producerId =
ID:tamarama-62436-1191396093006-2:2:1:3, destination =
queue://worker-items, transactionId =
TX:ID:tamarama-62436-1191396093006-2:2:5, expiration = 0, timestamp =
1191396097286, arrival = 0, brokerInTime = 1191396097290, brokerOutTime
= 1191396097417, correlationId = null, replyTo = null, persistent =
true, type = null, priority = 4, groupID = null, groupSequence = 0,
targetConsumerId = null, compressed = false, userID = null, content =
[EMAIL PROTECTED], marshalledProperties =
null, dataStructure = null, redeliveryCounter = 0, size = 0, properties
= null, readOnlyProperties = true, readOnlyBody = true, droppable =
false}, redeliveryCounter = 0}
I'll need to do more investigations tomorrow, but if anybody has any
ideas, I'd appreciate some insights.
--
Cheers,
David
Nuix Pty Ltd
Suite 79, 89 Jones St, Ultimo NSW 2007, Australia Ph: +61 2 9280 0699
Web: http://www.nuix.com Fax: +61 2 9212 6902
