Open Stack

On 23/09/2016 3:19 AM, Zhai, Edwin wrote:
> "Each notification listener is associated with an executor which
> controls how incoming notification messages will be received and
> dispatched. By default, the most simple executor is used - the blocking
> executor. This executor processes inbound notifications on the server’s
> thread, blocking it from processing additional notifications until it
> finishes with the current one."

we use threading executor[1] not blocking. unless something has changed 
with oslo.messaging recently, the behaviour is: you have 64 threads 
grabbing messages off queue. because it's all threads and we don't 
really know when they context switch so you can't guarantee order 
(unless you switch to one thread).

[1] 
https://github.com/openstack/aodh/blob/9c5df8400b621141db93a259900efe3702eb6241/aodh/messaging.py#L54

cheers,
-- 
gord