From: Carl Baldwin <carl.baldwin@hp.com>
Date: Fri, 17 Jan 2014 19:28:10 +0000 (+0000)
Subject: Use an independent iptables lock per namespace
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=d2c99f080ad2ee03c380b58b9fbac51cf16a57eb;p=openstack-build%2Fneutron-build.git

Use an independent iptables lock per namespace

Since iptables is independent from namespace to namespace, it makes
sense to use an independent lock per namespace.  This improvement is
aimed at improving the parallel performance in the L3 agent.

Partially implements blueprint: neutron-tempest-parallel

Change-Id: I15e9c9da9a7c15981757a09bc744501722d62db2
---

diff --git a/neutron/agent/linux/iptables_manager.py b/neutron/agent/linux/iptables_manager.py
index f33478af6..87372f03b 100644
--- a/neutron/agent/linux/iptables_manager.py
+++ b/neutron/agent/linux/iptables_manager.py
@@ -26,6 +26,7 @@ import os
 
 from neutron.agent.linux import utils as linux_utils
 from neutron.common import utils
+from neutron.openstack.common import lockutils
 from neutron.openstack.common import log as logging
 
 LOG = logging.getLogger(__name__)
@@ -351,8 +352,19 @@ class IptablesManager(object):
 
         self._apply()
 
-    @utils.synchronized('iptables', external=True)
     def _apply(self):
+        lock_name = 'iptables'
+        if self.namespace:
+            lock_name += '-' + self.namespace
+
+        try:
+            with lockutils.lock(lock_name, utils.SYNCHRONIZED_PREFIX, True):
+                LOG.debug(_('Got semaphore / lock "%s"'), lock_name)
+                return self._apply_synchronized()
+        finally:
+            LOG.debug(_('Semaphore / lock released "%s"'), lock_name)
+
+    def _apply_synchronized(self):
         """Apply the current in-memory set of iptables rules.
 
         This will blow away any rules left over from previous runs of the
diff --git a/neutron/common/utils.py b/neutron/common/utils.py
index 5e8cab756..1a806ab49 100644
--- a/neutron/common/utils.py
+++ b/neutron/common/utils.py
@@ -36,8 +36,9 @@ from neutron.openstack.common import log as logging
 
 TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
 LOG = logging.getLogger(__name__)
+SYNCHRONIZED_PREFIX = 'neutron-'
 
-synchronized = lockutils.synchronized_with_prefix('neutron-')
+synchronized = lockutils.synchronized_with_prefix(SYNCHRONIZED_PREFIX)
 
 
 def read_cached_file(filename, cache_info, reload_func=None):