Why does instances fail to start after patching compute node with error "filter 'nova-instance-instance-xxx-yyy' already exists with uuid" ?

Issue

• After upgrade of RHEL 7.0 based compute node to latest packages, existing instances fail to start .
• Existing Instance fail to start when nwfilter is already defined .
• Instance fail with error "filter 'nova-instance-instance-xxx-yyy' already exists with uuid" .

2015-03-24 11:32:21.175 3112 ERROR oslo.messaging.rpc.dispatcher [-] Exception during message handling: operation failed: filter 'nova-instance-instance-0000008a-fa163e4965fe' already exists with uuid 552e20d8-c90b-7bbf-6909-d6e4c8e9f4ac
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher Traceback (most recent call last):
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/oslo/messaging/rpc/dispatcher.py", line 133, in _dispatch_and_reply
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     incoming.message))
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/oslo/messaging/rpc/dispatcher.py", line 176, in _dispatch
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     return self._do_dispatch(endpoint, method, ctxt, args)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/oslo/messaging/rpc/dispatcher.py", line 122, in _do_dispatch
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     result = getattr(endpoint, method)(ctxt, **new_args)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/exception.py", line 88, in wrapped
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     payload)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     six.reraise(self.type_, self.value, self.tb)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/exception.py", line 71, in wrapped
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     return f(self, context, *args, **kw)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 276, in decorated_function
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     pass
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     six.reraise(self.type_, self.value, self.tb)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 262, in decorated_function
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     return function(self, context, *args, **kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 329, in decorated_function
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     function(self, context, *args, **kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 305, in decorated_function
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     e, sys.exc_info())
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     six.reraise(self.type_, self.value, self.tb)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 292, in decorated_function
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     return function(self, context, *args, **kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2330, in start_instance
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     self._power_on(context, instance)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2318, in _power_on
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     block_device_info)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2198, in power_on
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     self._hard_reboot(context, instance, network_info, block_device_info)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2162, in _hard_reboot
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     vifs_already_plugged=True)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 3740, in _create_domain_and_network
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     network_info)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/firewall.py", line 285, in setup_basic_filtering
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     self.nwfilter.setup_basic_filtering(instance, network_info)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/firewall.py", line 126, in setup_basic_filtering
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     vif))
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/firewall.py", line 233, in _define_filter
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     self._conn.nwfilterDefineXML(xml)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 179, in doit
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     result = proxy_call(self._autowrap, f, *args, **kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 139, in proxy_call
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     rv = execute(f,*args,**kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 77, in tworker
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     rv = meth(*args,**kwargs)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher   File "/usr/lib64/python2.7/site-packages/libvirt.py", line 4044, in nwfilterDefineXML
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher     if ret is None:raise libvirtError('virNWFilterDefineXML() failed', conn=self)
2015-03-24 11:32:21.175 3112 TRACE oslo.messaging.rpc.dispatcher libvirtError: operation failed: filter 'nova-instance-instance-0000008a-fa163e4965fe' already exists with uuid 552e20d8-c90b-7bbf-6909-d6e4c8e9f4ac