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https://issues.apache.org/activemq/browse/AMQ-1807?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Dejan Bosanac resolved AMQ-1807.
--------------------------------
Resolution: Fixed
The problem with dispatch stopping after transaction abort was due to the fact
that messages were acked at the moment they were dispatched and we didn't have
any logic to redeliver them after the rollback. I implemented some additional
logic (Committed revision 738904), that acks messages received in the
transaction on commit, and redeliver them after the abort. This helps in this
usecase, as you can see in the StompTest.testPrefetchSize().
I still can imagine certain scenarios where this would not work well, mostly
because we dispatch messages as they come to the transport and don't care
whether some of already dispatched messages should be redelivered before, but
this requires quite a big refactoring, so I leave it for the future
enhancements.
> Activemq stops dispatching messages aborting transaction (STOMP)
> ----------------------------------------------------------------
>
> Key: AMQ-1807
> URL: https://issues.apache.org/activemq/browse/AMQ-1807
> Project: ActiveMQ
> Issue Type: Bug
> Components: Transport
> Affects Versions: 5.1.0
> Environment: Linux, JDK 1.6_06b2
> Reporter: Celso Pinto
> Assignee: Dejan Bosanac
> Priority: Critical
> Fix For: 5.3.0
>
> Attachments: stomp_test.patch
>
>
> As requested by Dejan Bosanac, I'm adding this ticket. I'm willing to help
> fix it, ie. I can get my hands dirty, but I must have some pointers on where
> to look because (unfortunately) I don't have much time to learn ActiveMQ's
> internals and architecture.
> A copy of the email I sent to the users mailing-list:
> =============================================
> I'm currently struggling to understand the reason behind that's causing the
> behaviour described in the subject: I'm connecting to activemq via stomp on a
> python app. Because I need to have the messages rolled back in case of some
> processing failure I'm wrapping the message processing in the following way:
> message received -> start transaction -> ack message in transaction ->
> process message -> if no exception commit tx, else rollback transaction
> AFAIK, this is the only way of making message unacknowledgement possible with
> stomp. Also, this is a single client connection, ie. I'm using a
> single client connection to create a message processing daemon, all messages
> are sent and received via this single connection to the MQ server.
> Here's a telnet session that can be used to reproduce the problem (open
> jconsole and send 5 text messages to the queue):
> % telnet localhost 61613
> Trying 127.0.0.1...
> Connected to localhost.
> Escape character is '^]'.
> CONNECT
> ^@
> CONNECTED
> session:ID:starfish-53281-1213736462979-2:2
> SUBSCRIBE
> destination: /queue/testq
> ack: client
> activemq.prefetchSize: 1
> ^@
> MESSAGE
> message-id:ID:starfish-53281-1213736462979-3:3:1:1:1
> destination:/queue/testq
> timestamp:1213736837743
> expires:0
> priority:0
> 1
> BEGIN
> transaction: 1
> ^@
> ACK
> message-id:ID:starfish-53281-1213736462979-3:3:1:1:1
> transaction: 1
> ^@
> MESSAGE
> message-id:ID:starfish-53281-1213736462979-3:4:1:1:1
> destination:/queue/testq
> timestamp:1213736840224
> expires:0
> priority:0
> 2
> MESSAGE
> message-id:ID:starfish-53281-1213736462979-3:5:1:1:1
> destination:/queue/testq
> timestamp:1213736842611
> expires:0
> priority:0
> 3
> ABORT
> transaction: 1
> ^@
> BEGIN
> transaction:2
> ^@
> ACK
> message-id:ID:starfish-53281-1213736462979-3:4:1:1:1
> transaction:2
> ^@
> ABORT
> transaction:2
> ^@
> ACK
> message-id:ID:starfish-53281-1213736462979-3:5:1:1:1
> ^@
> I see a couple of issues here:
> #1) even though I specified activemq.prefetchSize to 1 in the subscription
> command, the connector dispatches two messages in a row
> #2) no more messages are dispatched after aborting the
> transaction/acknowledging the last received message. Even if the second
> message isn't wrapped in a transaction, message dispatch stops there.
> To add to the confusion, if I don't use transactions _at all_, my client
> keeps getting messages, one by one, ie. no two messages are sent together, I
> only get a new message after ACK'ing the previous one.
> I think I may be stepping into the realms of a buggy STOMP connector. Please
> tell me if I'm missing something obvious that fixes this issue
> (hence making it a non-issue) or if indeed the STOMP connector has problems.
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