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From James Green <>
Subject Re: Newbie questions on NMS or CMS ActiveMQ consumers puzzle
Date Wed, 01 Sep 2010 19:36:44 GMT
AIUI unless your client is operating in an "auto-ack" mode, the client
must "ack" each message it consumes to remove it from the queue.

This means that if you do not acknowledge the message, it will remain
for the next client. Pretty simple and prevents a client reading a
message then immediately crashing, losing the message forever.

Topics are similar however the message is only acknowledges to prevent
the same identified consumer receiving the same message more than

I'm still joining the party on message queues so someone chip in if
I'm wrong... :-)


On 1 September 2010 17:34, ChicagoBob123 <> wrote:
> Thanks for the feedback!
> I read this statement a couple of times from the link you sent and wondered
> if
> someone could elaborate further.
> "If a consumer receives a message and does not acknowledge it before closing
> "
> Closing what exactly? Closing the queue? The Session?
> The link also mentioned load balancing across consumers which seems exatcly
> like what I am experiencing, but what does this flag
> AcknowledgementMode.IndividualAcknowledge do for you then?
> Sorry I am so new and trying to get up to speed ASAP.
> --
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