[
https://issues.apache.org/activemq/browse/AMQ-2401?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=54412#action_54412
]
Colin MacNaughton commented on AMQ-2401:
----------------------------------------
The attached unit test can be used to demonstrate two issues. If you set
PRODUCER_COUNT=1 and CONSUMER_COUNT=1, and change the producer message size to
1300 bytes. You can see that this will indeed produce a hang since the
consumer's prefetch is 1000 and less than number fit into the queue.
However, using the test as is unmodified (e.g. 50 producers, and a message size
of 1024 doesn't result in a hang, but does result in a serious performance
bottleneck. There is some sort of contention happening in the broker. This is
the behavior that I was seeing in my original performance runs ... simply a
sever slow down.
> Hangs in fan-in to DUPS_OK_ACKNOWLEDGE queue receivers
> ------------------------------------------------------
>
> Key: AMQ-2401
> URL: https://issues.apache.org/activemq/browse/AMQ-2401
> Project: ActiveMQ
> Issue Type: Bug
> Affects Versions: 5.3.0
> Environment: Running with the following config:
> <destinationPolicy>
> <policyMap>
> <policyEntries>
> <policyEntry topic=">" producerFlowControl="true" memoryLimit="1mb">
>
> <pendingSubscriberPolicy>
> <vmCursor/>
> </pendingSubscriberPolicy>
> </policyEntry>
> <policyEntry queue=">" producerFlowControl="true" memoryLimit="1mb"/>
> </policyEntries>
> </policyMap>
> </destinationPolicy>
> Reporter: Colin MacNaughton
> Attachments: AMQ2401.txt
>
>
> While running performance tests I I was seeing hangs in several tests
> involving dups ok queue receivers. My suspicion is that this is related to
> "too lazy" dups_ok acknowledgements. Changing the queue prefetchLimit to 100
> caused this problem to go away. This needs more investigation, but it seems
> like we can get ourselves in to trouble if the queue size is smaller than the
> receiver's prefetchLimit, and this should be avoid. It is also possible that
> there is something more complicated happening in my tests. I haven't yet been
> able to reproduce this outside my performance test environment.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
