Merge lp:~cprov/adt-cloud-worker/qos into lp:adt-cloud-worker

[Celso Providelo]

Set a fair QoS to our multi-worker environment (prefetch_count=1)

Set a fair QoS to our multi-worker environment (prefetch_count=1)

[lp:~cprov/adt-cloud-worker/qos]

33. By Celso Providelo on 2015-03-20

better wording.

[Paul Larson (pwlars)]

Same question as the other related one, otherwise +1

review: Approve

=== modified file 'adt_cloud_worker/__init__.py'
--- adt_cloud_worker/__init__.py	2015-03-20 01:52:28 +0000
+++ adt_cloud_worker/__init__.py	2015-03-20 19:17:31 +0000
@@ -63,6 +63,10 @@
 
     def get_consumers(self, Consumer, channel):
         """Return consumers instances for all configured queues."""
+        # Set a fair QoS for a multi-worker environment with
+        # late-acknowledgement. Each worker should only be fed a single
+        # message at time (prefetch_count).
+        channel.basic_qos(prefetch_size=0, prefetch_count=1, a_global=False)
         exchange = kombu.Exchange("adt.exchange", type="topic")
         queues = [
             kombu.Queue(