def task_log_get_all(self, ctxt, cell_name, task_name,
                         period_beginning, period_ending,
                         host=None, state=None):
        method_kwargs = dict(task_name=task_name,
                             period_beginning=period_beginning,
                             period_ending=period_ending,
                             host=host, state=state)
        if cell_name:
            message = _TargetedMessage(self, ctxt, 'task_log_get_all',
                                    method_kwargs, 'down',
                                    cell_name, need_response=True)
            # Caller should get a list of Responses.
            return [message.process()]
        message = _BroadcastMessage(self, ctxt, 'task_log_get_all',
                                    method_kwargs, 'down',
                                    run_locally=True, need_response=True)
        return message.process()
Get task logs from the DB from all cells or a particular
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/cells/messaging.py/MessageRunner.task_log_get_all