[rabbitmq-discuss] RPC style messaging with a clustered web application

[Marek Majkowski]

On Thu, Dec 2, 2010 at 10:13, SimonT <simonthorogood at hotmail.com> wrote:
> I think that we probably need a response queue per session created at
> session start and some routing rules for the response messages based
> on the session ID. However, I'm not clear on how these queues could be
> expired once their purpose is complete? or if this is an issue?
> (though I assume it is since we have many 100s sessions a minute).
> There is no definitive 'end' to the session - currently it's
> serialized state just expires after x amount of idle time.

You should avoid having too many queues - they always consume
some resources.

Raw AMQP doesn't give any solution for this problem. Fortunately
in RabbitMQ we have queue leases extension:
http://www.rabbitmq.com/extensions.html#queue-leases

What it does, is it tells the broker that the queue should be auto-deleted
after a specified time of idleness.

Cheers,
  Marek