@Override
  public String toString() {
    return "KafkaIndexTaskTuningConfig{" +
        "maxRowsInMemory=" + getMaxRowsInMemory() +
        ", maxRowsPerSegment=" + getMaxRowsPerSegment() +
        ", maxTotalRows=" + getMaxTotalRows() +
        ", maxBytesInMemory=" + getMaxBytesInMemory() +
        ", intermediatePersistPeriod=" + getIntermediatePersistPeriod() +
        ", basePersistDirectory=" + getBasePersistDirectory() +
        ", maxPendingPersists=" + getMaxPendingPersists() +
        ", indexSpec=" + getIndexSpec() +
        ", indexSpecForIntermediatePersists=" + getIndexSpecForIntermediatePersists() +
        ", reportParseExceptions=" + isReportParseExceptions() +
        ", handoffConditionTimeout=" + getHandoffConditionTimeout() +
        ", resetOffsetAutomatically=" + isResetOffsetAutomatically() +
        ", segmentWriteOutMediumFactory=" + getSegmentWriteOutMediumFactory() +
        ", intermediateHandoffPeriod=" + getIntermediateHandoffPeriod() +
        ", logParseExceptions=" + isLogParseExceptions() +
        ", maxParseExceptions=" + getMaxParseExceptions() +
        ", maxSavedParseExceptions=" + getMaxSavedParseExceptions() +
        '}';
  }
This class is copied from druid source code
in order to avoid adding additional dependencies on druid-indexing-service.
druid-handler/src/java/org/apache/hadoop/hive/druid/json/KafkaIndexTaskTuningConfig.java