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https://issues.apache.org/jira/browse/AMQ-5712?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14492786#comment-14492786
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Christopher L. Shannon commented on AMQ-5712:
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[~paulgale], Our entire issue is that we occasionally have slow consumers which
fill up our entire memory store (and temporary store) which is causing the
deadlock. This is the reason we can't use the vmCursor as we need to be able
to spill over onto to disk when the memory store fills up. Also, in our case
the jms producer is setting the deliver mode as non-persistent (so the temp
store gets used), but it could just as easily switch to persistent. We want
the queue to be set up so the producer can decide if it wants to publish
persistent or non persistent messages.
> Broker can deadlock when using queues while producers wait on disk space
> ------------------------------------------------------------------------
>
> Key: AMQ-5712
> URL: https://issues.apache.org/jira/browse/AMQ-5712
> Project: ActiveMQ
> Issue Type: Bug
> Components: Broker
> Affects Versions: 5.11.1
> Reporter: Christopher L. Shannon
>
> I am experiencing a deadlock when using a Queue with non-persistent messages.
> The queue has a cursor high memory water mark set (right now at 70%). When
> a producer is producing messages quickly to the queue and that limit gets
> hit, the broker can deadlock. I have tried setting producerWindowSize and
> alwaysSyncSend which did not seem to help. When the broker hits that limit, I
> am unable to do things like purge the queue. Consumers can also deadlock as
> well.
> Note that this appears to be the same issue as described in this ticket here:
> AMQ-2475 . The difference is that I am using a Queue and not a Topic and the
> fix for this appears to only have been for Topics.
> The problem appears to be in the Queue class on line 1852 inside the
> {{cursorAdd}} method. The method being called is {{return
> messages.addMessageLast(msg);}} which will block indefinitely if there is no
> space available, which in turn ties up the {{messagesLock}} from being used
> by any other threads. We have seen a deadlock where consumers can't consume
> because they are waiting on this lock. It looks like in AMQ-2475 part of
> the fix was to replace {{messages.addMessageLast(msg)}} with
> {{messages.tryAddMessageLast(msg, 10)}}. I also noticed that not all of the
> message cursors support {{tryAddMessageLast}}, which could be a problem.
> {{FilePendingMessageCursor}} implements it but the rest of the cursors
> (notably {{StoreQueueCursor}}) simply delegate back to {{addMessageLast}} in
> the parent class. So part of this fix may require implementing
> {{tryAddMessageLast}} across more cursors.
> Here is part of the thread dump showing the stuck producer:
> {code}
> "ActiveMQ Transport: ssl:///192.168.3.142:38589" daemon prio=10
> tid=0x00007fb46c006000 nid=0x3b1a runnable [0x00007fb4b8a0d000]
> java.lang.Thread.State: TIMED_WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00000000cfb13cd0> (a
> java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
> at
> java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2176)
> at org.apache.activemq.usage.Usage.waitForSpace(Usage.java:103)
> at org.apache.activemq.usage.Usage.waitForSpace(Usage.java:90)
> at org.apache.activemq.usage.Usage.waitForSpace(Usage.java:80)
> at
> org.apache.activemq.broker.region.cursors.FilePendingMessageCursor.tryAddMessageLast(FilePendingMessageCursor.java:235)
> - locked <0x00000000d2015ee0> (a
> org.apache.activemq.broker.region.cursors.FilePendingMessageCursor)
> at
> org.apache.activemq.broker.region.cursors.FilePendingMessageCursor.addMessageLast(FilePendingMessageCursor.java:207)
> - locked <0x00000000d2015ee0> (a
> org.apache.activemq.broker.region.cursors.FilePendingMessageCursor)
> at
> org.apache.activemq.broker.region.cursors.StoreQueueCursor.addMessageLast(StoreQueueCursor.java:97)
> - locked <0x00000000d1f20908> (a
> org.apache.activemq.broker.region.cursors.StoreQueueCursor)
> {code}
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