def task_log_get_all(self, ctxt, task_name, period_beginning,
                         period_ending, host=None, state=None):
        if host is None:
            cell_name = None
        else:
            cell_name, host = cells_utils.split_cell_and_item(host)
            # If no cell name was given, assume that the host name is the
            # cell_name and that the target is all hosts
            if cell_name is None:
                cell_name, host = host, cell_name
        responses = self.msg_runner.task_log_get_all(ctxt, cell_name,
                task_name, period_beginning, period_ending,
                host=host, state=state)
        # 1 response per cell.  Each response is a list of task log
        # entries.
        ret_task_logs = []
        for response in responses:
            task_logs = response.value_or_raise()
            for task_log in task_logs:
                cells_utils.add_cell_to_task_log(task_log,
                                                 response.cell_name)
                ret_task_logs.append(task_log)
        return ret_task_logs
Get task logs from the DB from all cells or a particular
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/cells/manager.py/CellsManager.task_log_get_all