From f2beb5eaf158f76cdb8be0ca72965503be423ee2 Mon Sep 17 00:00:00 2001
From: John Eckersberg <jeckersb@redhat.com>
Date: Fri, 2 Oct 2015 13:47:21 -0400
Subject: [PATCH] rabbit: shuffle hosts before building kombu URL
This restores behavior as it was back in the Juno cycle. This was
changed in a refactor during the Kilo cycle (973301aa) when the kombu
failover_strategy was set to shuffle. But the failover_strategy only
affects failovers; it does not influence which host receives the
initial connection.
Thus, if multiple hosts are given, the first host will receive all of
the initial connections. By shuffling the hosts before building the
URL given to kombu, rudimentary load balancing is achieved and
connections are more evenly spread across broker nodes.
Change-Id: Ieecaf5f286f49302db29df9854359ef5d36b7a89
---
oslo_messaging/_drivers/impl_rabbit.py | 3 +++
1 file changed, 3 insertions(+)
diff --git a/oslo_messaging/_drivers/impl_rabbit.py b/oslo_messaging/_drivers/impl_rabbit.py
index cbdb4ed7e..89ea619d9 100644
--- a/oslo_messaging/_drivers/impl_rabbit.py
+++ b/oslo_messaging/_drivers/impl_rabbit.py
@@ -16,6 +16,7 @@ import collections
import contextlib
import functools
import os
+import random
import socket
import ssl
import threading
@@ -406,6 +407,7 @@ class Connection(object):
LOG.warn(_LW('Selecting the kombu transport through the '
'transport url (%s) is a experimental feature '
'and this is not yet supported.') % url.transport)
+ random.shuffle(url.hosts)
for host in url.hosts:
transport = url.transport.replace('kombu+', '')
transport = transport.replace('rabbit', 'amqp')
@@ -423,6 +425,7 @@ class Connection(object):
transport = url.transport.replace('kombu+', '')
self._url = "%s://%s" % (transport, virtual_host)
else:
+ random.shuffle(self.rabbit_hosts)
for adr in self.rabbit_hosts:
hostname, port = netutils.parse_host_port(
adr, default_port=self.rabbit_port)