@Override
  public SettableFuture<ConfigTaskResult> getTimeSlotList(
      final GetTimeSlotListStatement getTimeSlotListStatement) {
    final SettableFuture<ConfigTaskResult> future = SettableFuture.create();
    TGetTimeSlotListResp resp = new TGetTimeSlotListResp();
    try (final ConfigNodeClient configNodeClient =
        CONFIG_NODE_CLIENT_MANAGER.borrowClient(ConfigNodeInfo.CONFIG_REGION_ID)) {
      final TGetTimeSlotListReq tGetTimeSlotListReq = new TGetTimeSlotListReq();
      if (getTimeSlotListStatement.getDatabase() != null) {
        tGetTimeSlotListReq.setDatabase(getTimeSlotListStatement.getDatabase());
      } else if (getTimeSlotListStatement.getDevice() != null) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        getTimeSlotListStatement.getDevice().serialize(baos);
        tGetTimeSlotListReq.setDevice(baos.toByteArray());
      } else if (getTimeSlotListStatement.getRegionId() != -1) {
        tGetTimeSlotListReq.setRegionId(getTimeSlotListStatement.getRegionId());
      }
      if (getTimeSlotListStatement.getStartTime() != -1) {
        tGetTimeSlotListReq.setStartTime(getTimeSlotListStatement.getStartTime());
      }
      if (getTimeSlotListStatement.getEndTime() != -1) {
        tGetTimeSlotListReq.setEndTime(getTimeSlotListStatement.getEndTime());
      }
      resp = configNodeClient.getTimeSlotList(tGetTimeSlotListReq);
      if (resp.getStatus().getCode() != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
        future.setException(new IoTDBException(resp.getStatus().message, resp.getStatus().code));
        return future;
      }
    } catch (final Exception e) {
      future.setException(e);
    }
    GetTimeSlotListTask.buildTSBlock(resp, future);
    return future;
  }
FIXME Consolidate this clientManager with the upper one.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/execution/config/executor/ClusterConfigTaskExecutor.java