[rabbitmq-discuss] Implementing Prioritised Queues

Fri Oct 14 12:07:14 BST 2011

> How does QoS manage to load-balance multiple queues within a channel?
> I thought the queue consulted the limiter before delivering a new
> message...in that case could one add a little bit of logic to the
> limiter to prefer one queue over another? I believe there is already
> some logic in the limiter that tracks rejection rates per
> queue...could this be implemented as an extension to that?

Not really, it's "one phase commit" -- the queue says "will you take 
this message?" and the limiter either commits and gets the message, or 
doesn't and is thereafter considered blocked.  Thus there's no 
opportunity to defer acceptance.

Prioritising consumers for a queue would be easier I think, but sadly 
that is the one permutation that no-one seems to need.

-Michael

> On 14 October 2011 10:43, Matthias Radestock<matthias at rabbitmq.com>  wrote:
>> James,
>>
>> On 14/10/11 10:36, James Dear wrote:
>>>
>>> It's kind of a pity that you have to go to such an elaborate setup
>>> client-side when I guess it (prioritizing different queues within a
>>> channel) would be a small feature to add server side. Can anyone
>>> familiar with the rabbitmq source comment on how difficult this might
>>> be to do?
>>
>> Very difficult indeed.
>>
>> Channels do not pull messages off queues. Queues send messages to channels.
>>
>> Matthias.
>>
> _______________________________________________
> rabbitmq-discuss mailing list
> rabbitmq-discuss at lists.rabbitmq.com
> https://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss