instance resize error

when resize an instance

nova.compute.manager [-] Remote error: AttributeError 'Network' object has no attribute 'multihost'
[u'Traceback (most recent call last):\n', u' File "/opt/stack/nova/nova/rpc/amqp.py", line 250, in _process_data\n rval = node_func(context=ctxt, **node_args)\n', u' File "/opt/stack/nova/nova/network/manager.py", line 1468, in setup_networks_on_host\n if not network[\'multihost\']:\n', u' File "/opt/stack/nova/nova/db/sqlalchemy/models.py", line 75, in __getitem__\n return getattr(self, key)\n', u"AttributeError: 'Network' object has no attribute 'multihost'\n"].. Setting instance vm_state to ERROR
2012-03-07 06:17:39 ERROR nova.rpc.common [-] Exception during message handling
(nova.rpc.common): TRACE: Traceback (most recent call last):
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/rpc/amqp.py", line 250, in _process_data
(nova.rpc.common): TRACE: rval = node_func(context=ctxt, **node_args)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/exception.py", line 114, in wrapped
(nova.rpc.common): TRACE: return f(*args, **kw)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 153, in decorated_function
(nova.rpc.common): TRACE: function(self, context, instance_uuid, *args, **kwargs)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 177, in decorated_function
(nova.rpc.common): TRACE: sys.exc_info())
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/contextlib.py", line 24, in __exit__
(nova.rpc.common): TRACE: self.gen.next()
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 171, in decorated_function
(nova.rpc.common): TRACE: return function(self, context, instance_uuid, *args, **kwargs)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 1416, in finish_resize
(nova.rpc.common): TRACE: self._set_instance_error_state(context, instance_ref.uuid)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/contextlib.py", line 24, in __exit__
(nova.rpc.common): TRACE: self.gen.next()
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 1411, in finish_resize
(nova.rpc.common): TRACE: disk_info, image)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/compute/manager.py", line 1369, in _finish_resize
(nova.rpc.common): TRACE: migration_ref['dest_compute'])
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/network/api.py", line 339, in setup_networks_on_host
(nova.rpc.common): TRACE: 'args': args})
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/rpc/__init__.py", line 69, in call
(nova.rpc.common): TRACE: return _get_impl().call(context, topic, msg, timeout)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/rpc/impl_kombu.py", line 671, in call
(nova.rpc.common): TRACE: return rpc_amqp.call(context, topic, msg, timeout, Connection.pool)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/rpc/amqp.py", line 336, in call
(nova.rpc.common): TRACE: rv = list(rv)
(nova.rpc.common): TRACE: File "/opt/stack/nova/nova/rpc/amqp.py", line 304, in __iter__
(nova.rpc.common): TRACE: raise result
(nova.rpc.common): TRACE: RemoteError: Remote error: AttributeError 'Network' object has no attribute 'multihost'
(nova.rpc.common): TRACE: [u'Traceback (most recent call last):\n', u' File "/opt/stack/nova/nova/rpc/amqp.py", line 250, in _process_data\n rval = node_func(context=ctxt, **node_args)\n', u' File "/opt/stack/nova/nova/network/manager.py", line 1468, in setup_networks_on_host\n if not network[\'multihost\']:\n', u' File "/opt/stack/nova/nova/db/sqlalchemy/models.py", line 75, in __getitem__\n return getattr(self, key)\n', u"AttributeError: 'Network' object has no attribute 'multihost'\n"].

the exception is duo to /nova/network/manager.py line 1468
         if not network['multihost']:

the network has no attribute of multihost .