neutron-metadata-agent failed to start

Traceback (most recent call last):
  File "/usr/bin/neutron-metadata-agent", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/dist-packages/neutron/agent/metadata/agent.py", line 378, in main
    config.init(sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/neutron/common/config.py", line 150, in init
    n_rpc.init(cfg.CONF)
  File "/usr/lib/python2.7/dist-packages/neutron/common/rpc.py", line 57, in init
    aliases=TRANSPORT_ALIASES)
  File "/usr/lib/python2.7/dist-packages/oslo/messaging/transport.py", line 185, in get_transport
    invoke_kwds=kwargs)
  File "/usr/local/lib/python2.7/dist-packages/stevedore/driver.py", line 45, in __init__
    verify_requirements=verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/named.py", line 55, in __init__
    verify_requirements)
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 170, in _load_plugins
    self._on_load_failure_callback(self, ep, err)
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 162, in _load_plugins
    verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/named.py", line 123, in _load_one_plugin
    verify_requirements,
  File "/usr/local/lib/python2.7/dist-packages/stevedore/extension.py", line 187, in _load_one_plugin
    obj = plugin(*invoke_args, **invoke_kwds)
  File "/usr/local/lib/python2.7/dist-packages/oslo_messaging/_drivers/impl_rabbit.py", line 1131, in __init__
    conf, conf.oslo_messaging_rabbit.rpc_conn_pool_size,
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2309, in __getattr__
    return self._conf._get(name, self._group)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2043, in _get
    value = self._do_get(name, group, namespace)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2061, in _do_get
    info = self._get_opt_info(name, group)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2185, in _get_opt_info
    group = self._get_group(group)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2169, in _get_group
    raise NoSuchGroupError(group_name)
oslo.config.cfg.NoSuchGroupError: no such group: <oslo_config.cfg.OptGroup object at 0x7feb0689ba50>