def _get_impl():
 global _RPCIMPL
 if (_RPCIMPL is None):
  try:
   _RPCIMPL = importutils.import_module(CONF.rpc_backend)
  except ImportError:
   impl = CONF.rpc_backend.replace('nova.rpc', 'nova.openstack.common.rpc')
   _RPCIMPL = importutils.import_module(impl)
 return _RPCIMPL

def _get_impl ( ) : global _RPCIMPL if ( _RPCIMPL is None ) : try : _RPCIMPL = importutils . import_module ( CONF . rpc_backend ) except ImportError : impl = CONF . rpc_backend . replace ( 'nova.rpc' , 'nova.openstack.common.rpc' ) _RPCIMPL = importutils . import_module ( impl ) return _RPCIMPL
delay import of rpc_backend until configuration is loaded .