nova-placement-api.log日志中错误Target WSGI script '/usr/bin/nova-placement-a...

日志中一直在报如下的错误，从网上没搜索到如何解决。请帮忙看看，非常感谢！、
raise ArgsAlreadyParsedError("cannot register CLI option")
ArgsAlreadyParsedError: arguments already parsed: cannot register CLI option
mod_wsgi (pid=13692): Target WSGI script '/usr/bin/nova-placement-api' cannot be loaded as Python module.
mod_wsgi (pid=13692): Exception occurred processing WSGI script '/usr/bin/nova-placement-api'.
Traceback (most recent call last):
  File "/usr/bin/nova-placement-api", line 54, in <module>
    application = init_application()
  File "/usr/lib/python2.7/site-packages/nova/api/openstack/placement/wsgi.py", line 53, in init_application
    config.parse_args([], default_config_files=[conffile])
  File "/usr/lib/python2.7/site-packages/nova/config.py", line 35, in parse_args
    log.register_options(CONF)
  File "/usr/lib/python2.7/site-packages/oslo_log/log.py", line 250, in register_options
    conf.register_cli_opts(_options.common_cli_opts)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2406, in __inner
    result = f(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2628, in register_cli_opts
    self.register_cli_opt(opt, group, clear_cache=False)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2410, in __inner
    return f(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2620, in register_cli_opt
    raise ArgsAlreadyParsedError("cannot register CLI option")
ArgsAlreadyParsedError: arguments already parsed: cannot register CLI option
mod_wsgi (pid=13691): Target WSGI script '/usr/bin/nova-placement-api' cannot be loaded as Python module.
mod_wsgi (pid=13691): Exception occurred processing WSGI script '/usr/bin/nova-placement-api'.
Traceback (most recent call last):
  File "/usr/bin/nova-placement-api", line 54, in <module>
    application = init_application()
  File "/usr/lib/python2.7/site-packages/nova/api/openstack/placement/wsgi.py", line 53, in init_application
    config.parse_args([], default_config_files=[conffile])
  File "/usr/lib/python2.7/site-packages/nova/config.py", line 35, in parse_args
    log.register_options(CONF)
  File "/usr/lib/python2.7/site-packages/oslo_log/log.py", line 250, in register_options
    conf.register_cli_opts(_options.common_cli_opts)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2406, in __inner
    result = f(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2628, in register_cli_opts
    self.register_cli_opt(opt, group, clear_cache=False)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2410, in __inner
    return f(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2620, in register_cli_opt
    raise ArgsAlreadyParsedError("cannot register CLI option")
ArgsAlreadyParsedError: arguments already parsed: cannot register CLI option

可能keystone的问题。检测Nova的keystone相关设置。在找找其它日志或则错误。