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Date: Fri, 7 Aug 2009 09:42:16 -0700 (PDT)
From: jerdavis <jerdavis@speakeasy.net>
To: users@activemq.apache.org
Subject: Re: Total Message Order of Queues (not topics) durring edge
  cases(crashes)
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References: <24705154.post@talk.nabble.com> <24837185.post@talk.nabble.com>
 <99DC3C9B-89E9-4711-87B0-59F3CAF3712E@gmail.com>
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 <3a73c17c0908070340t6ab6d674gb29ed6c87eef40b7@mail.gmail.com>


I guess the edge case I'm thinking about is the Plain ol Single Consumer
that crashes. If my crashed program quickly restarts, and starts consuming,
I bet the broker would think there are two consumers (until TCP timeouts
etc)

Many thanks to all, I can sleep better now.
-JD


Gary Tully wrote:
> 
> total ordering is only an issue when there are multiple consumers.
> For a single consumer and for exclusive consumers, where there can only be
> a
> single consumer, ordering 'is' guaranteed.
> 
> 2009/8/6 jerdavis <jerdavis@speakeasy.net>
> 
>>
>> Thanks for your answer Rob, this is exactly what I was looking for. :)
>> Total Ordering seems like such a fundamental thing for a Persistent
>> Queue.
>> I'm surprised there hasn't been a solid answer to this question. Is there
>> a
>> standard way people get around this?
>> Would an Exclusive Consumer guarantee Total Order?
>> I would think that a new Exclusive consumer wouldn't be able to consume
>> messages until the crashed TCP connection/consumer finally closed and
>> released the outstanding messages.
>>
>> Regards,
>> -JD
>>
>>
>>
>>
>>
>>
>> rajdavies wrote:
>> >
>> >
>> > On 5 Aug 2009, at 23:13, jerdavis wrote:
>> >
>> >>
>> >> No takers?
>> >> --
>> >> View this message in context:
>> >>
>> http://www.nabble.com/Total-Message-Order-of-Queues-%28not-topics%29-durring-edge-cases%28crashes%29-tp24705154p24837185.html
>> >> Sent from the ActiveMQ - User mailing list archive at Nabble.com.
>> >>
>> >
>> >
>> > Total ordering may be violated for consumer crashes with the default
>> > prefetch sizes - see
>> > http://activemq.apache.org/what-is-the-prefetch-limit-for.html
>> >   to reduce this possibility to a single message - set a prefetch size
>> > = 0.
>> >
>> > cheers,
>> >
>> > Rob
>> >
>> > Rob Davies
>> > I work here: http://fusesource.com
>> > My Blog: http://rajdavies.blogspot.com/
>> > I'm writing this: http://www.manning.com/snyder/
>> >
>> >
>> >
>> >
>> >
>> >
>>
>> --
>> View this message in context:
>> http://www.nabble.com/Total-Message-Order-of-Queues-%28not-topics%29-durring-edge-cases%28crashes%29-tp24705154p24855824.html
>> Sent from the ActiveMQ - User mailing list archive at Nabble.com.
>>
>>
> 
> 
> -- 
> http://blog.garytully.com
> 
> Open Source Integration
> http://fusesource.com
> 
> 

-- 
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