Kill the Redis servers.

        Args:
            check_alive (bool): Raise an exception if any of the processes
                were already dead.

def kill_redis(self, check_alive=True):
        """Kill the Redis servers.

        Args:
            check_alive (bool): Raise an exception if any of the processes
                were already dead.
        """
        self._kill_process_type(
            ray_constants.PROCESS_TYPE_REDIS_SERVER, check_alive=check_alive)