def _client(self, host, port, unix_socket, auth):
        """Return a redis client for the configuration.

:param str host: redis host
:param int port: redis port
:rtype: redis.Redis

        """
        db = int(self.config['db'])
        timeout = int(self.config['timeout'])
        try:
            cli = redis.Redis(host=host, port=port,
                              db=db, socket_timeout=timeout, password=auth,
                              unix_socket_path=unix_socket)
            cli.ping()
            return cli
        except Exception as ex:
            self.log.error("RedisCollector: failed to connect to %s:%i. %s.",
                           unix_socket or host, port, ex)
Return a redis client for the configuration.

:param str host: redis host
:param int port: redis port
:rtype: redis.Redis