[rabbitmq-discuss] Question about configuration of queues

Fri Nov 7 16:22:10 GMT 2008

On Tue, Nov 4, 2008 at 9:46 PM, Edwin Fine
<rabbitmq-discuss_efine at usa.net> wrote:
>
> On Tue, Nov 4, 2008 at 5:41 PM, Beene, William R. <beenewilliamr at gmail.com>
> wrote:
>>
>> On Tue, Nov 4, 2008 at 4:34 PM, Ben Hood <0x6e6562 at gmail.com> wrote:
>> > William,
>> >
>> > On Tue, Nov 4, 2008 at 10:05 PM, Beene, William R.
>> > <beenewilliamr at gmail.com> wrote:
>> >> Is there anyway to preconfigure a queue in rabbitmq before my app that
>> >> needs the queue starts up.
>> >> I want data sent to the queue to be persisted so that the app can get
>> >> it when it starts up.
>> >> Does this use case make sense? Is this possible? Any pointers would be
>> >> greatly appreciated.
>> >
>> > Why don't just declare the queue, send the messages that you want to
>> > pre-populate the queue with (setting the persistent flag when sending)
>> > and then after this has occurred, start a consumer to receive the
>> > messages?
>> >
>> > HTH,
>> >
>> > Ben
>> >
>>
>> Because then the producers would have to know about all of the consumers.
>> I would rather put this in a property file or something. It looks like
>> I may have to write a small program that reads a property file and creates
>>  the queues I need.
>
> William,
>
> If I understood your question correctly, I don't see why the producers would
> need to know all about the consumers.
>
> The producers publish to an exchange using a routing key. In a simple
> scenario, the routing key is just a queue name. The producers would have to
> know the key to be able to publish to that queue.
>
> You can set it up so that whichever actor (consumer or producer) first tries
> to access the queue creates it (if the flags are set up to do this). If the
> consumer gets there first, it will create an empty queue and sit and wait on
> it, or come back later and try again. If it's the producer that first starts
> up, it will create the queue, and as long as the messages you deliver are
> flagged as persistent (assuming you want them to survive the rabbit server
> restart), and not flagged for immediate delivery, the producer can happily
> throw stuff in the queue (within reasonable memory limitations). The
> consumer(s) may start up at any time and collect the messages. An
> application I wrote works very much like this.
>
> It may seem strange to let the consumers create the queues but, security
> aspects aside (assuming that consumers are trusted), it's a very convenient
> way to do what you want to do. (It can be confusing if the consumer uses the
> wrong queue name, because it may create an empty queue and sit there forever
> wondering why nobody is talking to it, but that's true of a lot of things in
> general).
>
> Does this help?
>
> Regards,
> Edwin Fine
>
>>
>> Thanks,
>> William Beene
>>
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>>
>
>

Edwin & Ben,

Thanks for your help. I think I can proceed now.

Thanks,
William