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[Eric Windisch <eric@xxxxxxxxxxxxxxxx>]

Sure, but then the contract becomes between the notifier and the client, presumably? I'm not as familiar with the notification system as I should be. 

I haven't written a ZeroMQ notifier yet, figuring that task would be better delayed until the move to openstack-common. 

-- 
Eric Windisch


On Wednesday, April 25, 2012 at 3:29 PM, Russell Bryant wrote:

> On 04/25/2012 03:22 PM, Eric Windisch wrote:
> > I've heard a few people mention pulling messages off the queue, or
> > communicating via RPC outside of the project, or outside of Python. In
> > theory, this sounds nice, but the RPC implementations are strictly
> > making sure that A can execute calls on target B and that responses get
> > back to A.
> > 
> > This has little to do with message queues, other than that message
> > queues are optionally supported. You shouldn't be peeking behind that
> > curtain. This is specific to each RPC mechanism and enforcing something
> > this early might be more problematic than you expect.
> > 
> 
> 
> I agree with you that any discussion of other things poking at the rpc
> communications is broken and wrong.
> 
> The only case where it does make sense is notifications. In that case,
> the fact that it's using rpc is just an implementation detail. If you
> enable the rabbit notifier (should probably be renamed at some point),
> there is a specific AMQP message exchange where external applications
> are to receive notifications from nova.
> 
> This implementation detail means that this can also be used with zeromq
> ... though I'm not sure that makes sense. There would probably be a
> notifier implementation specific to zeromq that could make better use of
> that messaging model.
> 
> -- 
> Russell Bryant
> 
>