private void separateMeasurementAlreadyExistException(
        List<TSStatus> failingStatus,
        TSStatus executionStatus,
        List<TSStatus> alreadyExistingStatus) {
      // separate the measurement_already_exist exception and other exceptions process,
      // measurement_already_exist exception is acceptable due to concurrent timeseries creation
      if (failingStatus.isEmpty()) {
        if (executionStatus.getCode() == TSStatusCode.MULTIPLE_ERROR.getStatusCode()) {
          if (executionStatus.getSubStatus().get(0).getCode()
              == TSStatusCode.TIMESERIES_ALREADY_EXIST.getStatusCode()) {
            // there's only measurement_already_exist exception
            alreadyExistingStatus.addAll(executionStatus.getSubStatus());
          } else {
            failingStatus.addAll(executionStatus.getSubStatus());
          }
        } else if (executionStatus.getCode() != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
          failingStatus.add(executionStatus);
        }
      } else {
        if (executionStatus.getCode() == TSStatusCode.MULTIPLE_ERROR.getStatusCode()) {
          if (executionStatus.getSubStatus().get(0).getCode()
              != TSStatusCode.TIMESERIES_ALREADY_EXIST.getStatusCode()) {
            failingStatus.addAll(executionStatus.getSubStatus());
          }
        } else if (executionStatus.getCode() != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
          failingStatus.add(executionStatus);
        }
      }
    }
Check the quota before creating time series.

@return null if the quota is not exceeded, otherwise return the execution result.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/executor/RegionWriteExecutor.java