[ckan-dev] AMQP topic vs direct exchange

Tue Jan 11 09:53:34 UTC 2011

James,

Even if they have the same routing key, each worker has a different
queue instance (keyed in Carrot through the 'name'). Afaict any queue
can be setup to be 'durable' (ensures the config/setup of the queue is
persisted) and 'persisted' (ensures messages are persisted).

I can see there being a problem if two workers shared a queue, and one
consuming a message while the other worker was temporarily off-line,
but I don't think that is the case with Carrot.

David

On 10 January 2011 15:50, James Gardner <james at 3aims.com> wrote:
> Hi Friedrich,
>
> I had a good look at AMQP over Christmas and from what I can tell,
> workers can't consume a message from a topic queue unless they are
> running at the time the message was sent. This would mean messages sent
> to the queue could be lost even if durability settings were enabled.
>
> The core use case is one of a worker queue so I believe we should switch
> to a using a direct exchange as documented here:
> http://www.rabbitmq.com/tutorial-four-python.html or even the simpler
> version here: http://www.rabbitmq.com/tutorial-two-python.html
>
> Any thoughts?
>
> Cheers,
>
> James
>
>
>
>
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