/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.carbondata.spark.rdd

import java.io.File
import java.text.SimpleDateFormat
import java.util
import java.util.TimeZone
import java.util.concurrent._

import scala.collection.JavaConverters._
import scala.collection.mutable.ListBuffer
import scala.util.Random
import scala.util.control.Breaks._

import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.fs.Path
import org.apache.hadoop.io.NullWritable
import org.apache.hadoop.mapred.JobConf
import org.apache.hadoop.mapreduce.Job
import org.apache.hadoop.mapreduce.lib.input.{FileInputFormat, FileSplit}
import org.apache.spark.{SparkEnv, TaskContext}
import org.apache.spark.deploy.SparkHadoopUtil
import org.apache.spark.rdd.{DataLoadCoalescedRDD, DataLoadPartitionCoalescer, NewHadoopRDD, RDD}
import org.apache.spark.sql.{CarbonEnv, DataFrame, Row, SQLContext}
import org.apache.spark.sql.catalyst.TableIdentifier
import org.apache.spark.sql.execution.command.{CompactionModel, ExecutionErrors, UpdateTableModel}
import org.apache.spark.sql.hive.DistributionUtil
import org.apache.spark.sql.optimizer.CarbonFilters
import org.apache.spark.sql.util.{CarbonException, SparkSQLUtil}

import org.apache.carbondata.common.constants.LoggerAction
import org.apache.carbondata.common.logging.LogServiceFactory
import org.apache.carbondata.core.constants.{CarbonCommonConstants, SortScopeOptions}
import org.apache.carbondata.core.datamap.{DataMapStoreManager, Segment}
import org.apache.carbondata.core.datamap.status.DataMapStatusManager
import org.apache.carbondata.core.datastore.block.{Distributable, TableBlockInfo}
import org.apache.carbondata.core.datastore.compression.CompressorFactory
import org.apache.carbondata.core.datastore.filesystem.CarbonFile
import org.apache.carbondata.core.datastore.impl.FileFactory
import org.apache.carbondata.core.dictionary.server.DictionaryServer
import org.apache.carbondata.core.exception.ConcurrentOperationException
import org.apache.carbondata.core.locks.{CarbonLockFactory, ICarbonLock, LockUsage}
import org.apache.carbondata.core.metadata.{CarbonTableIdentifier, ColumnarFormatVersion, SegmentFileStore}
import org.apache.carbondata.core.metadata.datatype.DataTypes
import org.apache.carbondata.core.metadata.schema.partition.PartitionType
import org.apache.carbondata.core.metadata.schema.table.CarbonTable
import org.apache.carbondata.core.mutate.CarbonUpdateUtil
import org.apache.carbondata.core.scan.partition.PartitionUtil
import org.apache.carbondata.core.statusmanager.{LoadMetadataDetails, SegmentStatus, SegmentStatusManager}
import org.apache.carbondata.core.util.{ByteUtil, CarbonProperties, CarbonUtil, ThreadLocalSessionInfo}
import org.apache.carbondata.core.util.path.CarbonTablePath
import org.apache.carbondata.events.{OperationContext, OperationListenerBus}
import org.apache.carbondata.indexserver.IndexServer
import org.apache.carbondata.processing.exception.DataLoadingException
import org.apache.carbondata.processing.loading.FailureCauses
import org.apache.carbondata.processing.loading.csvinput.{BlockDetails, CSVInputFormat, StringArrayWritable}
import org.apache.carbondata.processing.loading.events.LoadEvents.{LoadTablePostStatusUpdateEvent, LoadTablePreStatusUpdateEvent}
import org.apache.carbondata.processing.loading.exception.NoRetryException
import org.apache.carbondata.processing.loading.model.{CarbonDataLoadSchema, CarbonLoadModel}
import org.apache.carbondata.processing.merger.{CarbonCompactionUtil, CarbonDataMergerUtil, CompactionType}
import org.apache.carbondata.processing.util.{Auditor, CarbonDataProcessorUtil, CarbonLoaderUtil}
import org.apache.carbondata.spark.{DataLoadResultImpl, PartitionFactory, _}
import org.apache.carbondata.spark.load._
import org.apache.carbondata.spark.util.{CarbonScalaUtil, CommonUtil, Util}

/**
 * This is the factory class which can create different RDD depends on user needs.
 *
 */
object CarbonDataRDDFactory {

  private val LOGGER = LogServiceFactory.getLogService(this.getClass.getCanonicalName)

  def handleCompactionForSystemLocking(sqlContext: SQLContext,
      carbonLoadModel: CarbonLoadModel,
      storeLocation: String,
      compactionType: CompactionType,
      carbonTable: CarbonTable,
      compactedSegments: java.util.List[String],
      compactionModel: CompactionModel,
      operationContext: OperationContext): Unit = {
    // taking system level lock at the mdt file location
    var configuredMdtPath = CarbonProperties.getInstance().getProperty(
      CarbonCommonConstants.CARBON_UPDATE_SYNC_FOLDER,
      CarbonCommonConstants.CARBON_UPDATE_SYNC_FOLDER_DEFAULT).trim

    configuredMdtPath = CarbonUtil.checkAndAppendFileSystemURIScheme(configuredMdtPath)
    val lock = CarbonLockFactory.getSystemLevelCarbonLockObj(
      configuredMdtPath + CarbonCommonConstants.FILE_SEPARATOR +
        CarbonCommonConstants.SYSTEM_LEVEL_COMPACTION_LOCK_FOLDER,
      LockUsage.SYSTEMLEVEL_COMPACTION_LOCK)

    if (lock.lockWithRetries()) {
      LOGGER.info(s"Acquired the compaction lock for table ${ carbonLoadModel.getDatabaseName }" +
          s".${ carbonLoadModel.getTableName }")
      try {
        startCompactionThreads(
          sqlContext,
          carbonLoadModel,
          storeLocation,
          compactionModel,
          lock,
          compactedSegments,
          operationContext
        )
      } catch {
        case e: Exception =>
          LOGGER.error(s"Exception in start compaction thread. ${ e.getMessage }")
          lock.unlock()
          // if the compaction is a blocking call then only need to throw the exception.
          if (compactionModel.isDDLTrigger) {
            throw e
          }
      }
    } else {
      LOGGER.error("Not able to acquire the compaction lock for table " +
          s"${ carbonLoadModel.getDatabaseName }.${ carbonLoadModel.getTableName }")
      CarbonCompactionUtil
          .createCompactionRequiredFile(carbonTable.getMetadataPath, compactionType)
      // throw exception only in case of DDL trigger.
      if (compactionModel.isDDLTrigger) {
        CarbonException.analysisException(
          s"Compaction is in progress, compaction request for table " +
            s"${carbonLoadModel.getDatabaseName}.${carbonLoadModel.getTableName}" +
            " is in queue.")
      } else {
        LOGGER.error("Compaction is in progress, compaction request for table " +
          s"${carbonLoadModel.getDatabaseName}.${carbonLoadModel.getTableName}" +
          " is in queue.")
      }
    }
  }

  def startCompactionThreads(sqlContext: SQLContext,
      carbonLoadModel: CarbonLoadModel,
      storeLocation: String,
      compactionModel: CompactionModel,
      compactionLock: ICarbonLock,
      compactedSegments: java.util.List[String],
      operationContext: OperationContext): Unit = {
    val executor: ExecutorService = Executors.newFixedThreadPool(1)
    // update the updated table status.
    if (compactionModel.compactionType != CompactionType.IUD_UPDDEL_DELTA) {
      // update the updated table status. For the case of Update Delta Compaction the Metadata
      // is filled in LoadModel, no need to refresh.
      carbonLoadModel.readAndSetLoadMetadataDetails()
    }

    val compactionThread = new Thread {
      override def run(): Unit = {
        val compactor = CompactionFactory.getCompactor(
          carbonLoadModel,
          compactionModel,
          executor,
          sqlContext,
          storeLocation,
          compactedSegments,
          operationContext)
        try {
          // compaction status of the table which is triggered by the user.
          var triggeredCompactionStatus = false
          var exception: Exception = null
          try {
            compactor.executeCompaction()
            triggeredCompactionStatus = true
          } catch {
            case e: Exception =>
              LOGGER.error(s"Exception in compaction thread ${ e.getMessage }")
              exception = e
          }
          // continue in case of exception also, check for all the tables.
          val isConcurrentCompactionAllowed = CarbonProperties.getInstance().getProperty(
            CarbonCommonConstants.ENABLE_CONCURRENT_COMPACTION,
            CarbonCommonConstants.DEFAULT_ENABLE_CONCURRENT_COMPACTION
          ).equalsIgnoreCase("true")

          if (!isConcurrentCompactionAllowed) {
            LOGGER.info("System level compaction lock is enabled.")
            val skipCompactionTables = ListBuffer[CarbonTableIdentifier]()
            var tableForCompaction = CarbonCompactionUtil.getNextTableToCompact(
              CarbonEnv.getInstance(sqlContext.sparkSession).carbonMetaStore
                .listAllTables(sqlContext.sparkSession).toArray,
              skipCompactionTables.toList.asJava)
            while (null != tableForCompaction) {
              LOGGER.info("Compaction request has been identified for table " +
                  s"${ tableForCompaction.getDatabaseName }." +
                  s"${ tableForCompaction.getTableName}")
              val table: CarbonTable = tableForCompaction
              val metadataPath = table.getMetadataPath
              val compactionType = CarbonCompactionUtil.determineCompactionType(metadataPath)

              val newCarbonLoadModel = prepareCarbonLoadModel(table)

              val compactionSize = CarbonDataMergerUtil
                .getCompactionSize(CompactionType.MAJOR, carbonLoadModel)

              val newcompactionModel = CompactionModel(
                compactionSize,
                compactionType,
                table,
                compactionModel.isDDLTrigger,
                CarbonFilters.getCurrentPartitions(sqlContext.sparkSession,
                  TableIdentifier(table.getTableName,
                  Some(table.getDatabaseName))), None)
              // proceed for compaction
              try {
                CompactionFactory.getCompactor(
                  newCarbonLoadModel,
                  newcompactionModel,
                  executor,
                  sqlContext,
                  storeLocation,
                  compactedSegments,
                  operationContext).executeCompaction()
              } catch {
                case e: Exception =>
                  LOGGER.error("Exception in compaction thread for table " +
                      s"${ tableForCompaction.getDatabaseName }." +
                      s"${ tableForCompaction.getTableName }")
                // not handling the exception. only logging as this is not the table triggered
                // by user.
              } finally {
                // delete the compaction required file in case of failure or success also.
                if (!CarbonCompactionUtil
                    .deleteCompactionRequiredFile(metadataPath, compactionType)) {
                  // if the compaction request file is not been able to delete then
                  // add those tables details to the skip list so that it wont be considered next.
                  skipCompactionTables.+=:(tableForCompaction.getCarbonTableIdentifier)
                  LOGGER.error("Compaction request file can not be deleted for table " +
                      s"${ tableForCompaction.getDatabaseName }." +
                      s"${ tableForCompaction.getTableName }")
                }
              }
              // ********* check again for all the tables.
              tableForCompaction = CarbonCompactionUtil.getNextTableToCompact(
                CarbonEnv.getInstance(sqlContext.sparkSession).carbonMetaStore
                  .listAllTables(sqlContext.sparkSession).toArray,
                skipCompactionTables.asJava)
            }
          }
          // Remove compacted segments from executor cache.
          if (CarbonProperties.getInstance().isDistributedPruningEnabled(
              carbonLoadModel.getDatabaseName, carbonLoadModel.getTableName)) {
            try {
              IndexServer.getClient.invalidateSegmentCache(carbonLoadModel
                .getCarbonDataLoadSchema.getCarbonTable,
                compactedSegments.asScala.toArray,
                SparkSQLUtil.getTaskGroupId(sqlContext.sparkSession))
            } catch {
              case ex: Exception =>
                LOGGER.warn(s"Clear cache job has failed for ${carbonLoadModel
                  .getDatabaseName}.${carbonLoadModel.getTableName}", ex)
            }
          }
          // giving the user his error for telling in the beeline if his triggered table
          // compaction is failed.
          if (!triggeredCompactionStatus) {
            throw new Exception("Exception in compaction " + exception.getMessage)
          }
        } finally {
          executor.shutdownNow()
          compactor.deletePartialLoadsInCompaction()
          if (compactionModel.compactionType != CompactionType.IUD_UPDDEL_DELTA) {
            compactionLock.unlock()
          }
        }
      }
    }
    // calling the run method of a thread to make the call as blocking call.
    // in the future we may make this as concurrent.
    compactionThread.run()
  }

  private def prepareCarbonLoadModel(
      table: CarbonTable
  ): CarbonLoadModel = {
    val loadModel = new CarbonLoadModel
    loadModel.setTableName(table.getTableName)
    val dataLoadSchema = new CarbonDataLoadSchema(table)
    // Need to fill dimension relation
    loadModel.setCarbonDataLoadSchema(dataLoadSchema)
    loadModel.setTableName(table.getCarbonTableIdentifier.getTableName)
    loadModel.setDatabaseName(table.getCarbonTableIdentifier.getDatabaseName)
    loadModel.setTablePath(table.getTablePath)
    loadModel.setCarbonTransactionalTable(table.isTransactionalTable)
    loadModel.readAndSetLoadMetadataDetails()
    val loadStartTime = CarbonUpdateUtil.readCurrentTime()
    loadModel.setFactTimeStamp(loadStartTime)
    val columnCompressor = table.getTableInfo.getFactTable.getTableProperties.asScala
      .getOrElse(CarbonCommonConstants.COMPRESSOR,
        CompressorFactory.getInstance().getCompressor.getName)
    loadModel.setColumnCompressor(columnCompressor)
    loadModel
  }

  def loadCarbonData(
      sqlContext: SQLContext,
      carbonLoadModel: CarbonLoadModel,
      columnar: Boolean,
      partitionStatus: SegmentStatus = SegmentStatus.SUCCESS,
      result: Option[DictionaryServer],
      overwriteTable: Boolean,
      hadoopConf: Configuration,
      dataFrame: Option[DataFrame] = None,
      updateModel: Option[UpdateTableModel] = None,
      operationContext: OperationContext): LoadMetadataDetails = {
    // Check if any load need to be deleted before loading new data
    val carbonTable = carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable
    var status: Array[(String, (LoadMetadataDetails, ExecutionErrors))] = null
    var res: Array[List[(String, (LoadMetadataDetails, ExecutionErrors))]] = null

    // create new segment folder  in carbon store
    if (updateModel.isEmpty && carbonLoadModel.isCarbonTransactionalTable) {
      CarbonLoaderUtil.checkAndCreateCarbonDataLocation(carbonLoadModel.getSegmentId, carbonTable)
    }
    var loadStatus = SegmentStatus.SUCCESS
    var errorMessage: String = "DataLoad failure"
    var executorMessage: String = ""
    val isSortTable = carbonTable.getNumberOfSortColumns > 0
    val sortScope = CarbonDataProcessorUtil.getSortScope(carbonLoadModel.getSortScope)

    val segmentLock = CarbonLockFactory.getCarbonLockObj(carbonTable.getAbsoluteTableIdentifier,
      CarbonTablePath.addSegmentPrefix(carbonLoadModel.getSegmentId) + LockUsage.LOCK)

    try {
      if (!carbonLoadModel.isCarbonTransactionalTable || segmentLock.lockWithRetries()) {
        if (updateModel.isDefined) {
          res = loadDataFrameForUpdate(
            sqlContext,
            dataFrame,
            carbonLoadModel,
            updateModel,
            carbonTable,
            hadoopConf)
          res.foreach { resultOfSeg =>
            resultOfSeg.foreach { resultOfBlock =>
              if (resultOfBlock._2._1.getSegmentStatus == SegmentStatus.LOAD_FAILURE) {
                loadStatus = SegmentStatus.LOAD_FAILURE
                if (resultOfBlock._2._2.failureCauses == FailureCauses.NONE) {
                  updateModel.get.executorErrors.failureCauses = FailureCauses.EXECUTOR_FAILURE
                  updateModel.get.executorErrors.errorMsg = "Failure in the Executor."
                } else {
                  updateModel.get.executorErrors = resultOfBlock._2._2
                }
              } else if (resultOfBlock._2._1.getSegmentStatus ==
                         SegmentStatus.LOAD_PARTIAL_SUCCESS) {
                loadStatus = SegmentStatus.LOAD_PARTIAL_SUCCESS
                updateModel.get.executorErrors.failureCauses = resultOfBlock._2._2.failureCauses
                updateModel.get.executorErrors.errorMsg = resultOfBlock._2._2.errorMsg
              }
            }
          }
        } else {
          status = if (carbonTable.getPartitionInfo(carbonTable.getTableName) != null) {
            loadDataForPartitionTable(sqlContext, dataFrame, carbonLoadModel, hadoopConf)
          } else if (dataFrame.isEmpty && isSortTable &&
                     carbonLoadModel.getRangePartitionColumn != null &&
                     (sortScope.equals(SortScopeOptions.SortScope.GLOBAL_SORT) ||
                      sortScope.equals(SortScopeOptions.SortScope.LOCAL_SORT))) {
            DataLoadProcessBuilderOnSpark
              .loadDataUsingRangeSort(sqlContext.sparkSession, carbonLoadModel, hadoopConf)
          } else if (isSortTable && sortScope.equals(SortScopeOptions.SortScope.GLOBAL_SORT)) {
            DataLoadProcessBuilderOnSpark.loadDataUsingGlobalSort(sqlContext.sparkSession,
              dataFrame, carbonLoadModel, hadoopConf)
          } else if (dataFrame.isDefined) {
            loadDataFrame(sqlContext, dataFrame, carbonLoadModel)
          } else {
            loadDataFile(sqlContext, carbonLoadModel, hadoopConf)
          }
          val newStatusMap = scala.collection.mutable.Map.empty[String, SegmentStatus]
          if (status.nonEmpty) {
            status.foreach { eachLoadStatus =>
              val state = newStatusMap.get(eachLoadStatus._1)
              state match {
                case Some(SegmentStatus.LOAD_FAILURE) =>
                  newStatusMap.put(eachLoadStatus._1, eachLoadStatus._2._1.getSegmentStatus)
                case Some(SegmentStatus.LOAD_PARTIAL_SUCCESS)
                  if eachLoadStatus._2._1.getSegmentStatus ==
                     SegmentStatus.SUCCESS =>
                  newStatusMap.put(eachLoadStatus._1, eachLoadStatus._2._1.getSegmentStatus)
                case _ =>
                  newStatusMap.put(eachLoadStatus._1, eachLoadStatus._2._1.getSegmentStatus)
              }
            }

            newStatusMap.foreach {
              case (key, value) =>
                if (value == SegmentStatus.LOAD_FAILURE) {
                  loadStatus = SegmentStatus.LOAD_FAILURE
                } else if (value == SegmentStatus.LOAD_PARTIAL_SUCCESS &&
                           loadStatus != SegmentStatus.LOAD_FAILURE) {
                  loadStatus = SegmentStatus.LOAD_PARTIAL_SUCCESS
                }
            }
          } else {
            // if no value is there in data load, make load status Success
            // and data load flow executes
            if (dataFrame.isDefined && updateModel.isEmpty) {
              val rdd = dataFrame.get.rdd
              if (rdd.partitions == null || rdd.partitions.length == 0) {
                LOGGER.warn("DataLoading finished. No data was loaded.")
                loadStatus = SegmentStatus.SUCCESS
              }
            } else {
              loadStatus = SegmentStatus.LOAD_FAILURE
            }
          }

          if (loadStatus != SegmentStatus.LOAD_FAILURE &&
              partitionStatus == SegmentStatus.LOAD_PARTIAL_SUCCESS) {
            loadStatus = partitionStatus
          }
        }
      }
    } catch {
      case ex: Throwable =>
        loadStatus = SegmentStatus.LOAD_FAILURE
        val (extrMsgLocal, errorMsgLocal) = CarbonScalaUtil.retrieveAndLogErrorMsg(ex, LOGGER)
        executorMessage = extrMsgLocal
        errorMessage = errorMsgLocal
        LOGGER.info(errorMessage)
        LOGGER.error(ex)
    } finally {
      segmentLock.unlock()
    }
    // handle the status file updation for the update cmd.
    if (updateModel.isDefined) {
      if (loadStatus == SegmentStatus.LOAD_FAILURE) {
        CarbonScalaUtil.updateErrorInUpdateModel(updateModel.get, executorMessage)
        return null
      } else if (loadStatus == SegmentStatus.LOAD_PARTIAL_SUCCESS &&
                 updateModel.get.executorErrors.failureCauses == FailureCauses.BAD_RECORDS &&
                 carbonLoadModel.getBadRecordsAction.split(",")(1) == LoggerAction.FAIL.name) {
        return null
      } else {
        // in success case handle updation of the table status file.
        // success case.
        // write the dictionary file in case of single_pass true
        writeDictionary(carbonLoadModel, result, false)
        val segmentDetails = new util.HashSet[Segment]()
        var resultSize = 0
        res.foreach { resultOfSeg =>
          resultSize = resultSize + resultOfSeg.size
          resultOfSeg.foreach { resultOfBlock =>
            segmentDetails.add(new Segment(resultOfBlock._2._1.getLoadName))
          }
        }
        val segmentFiles = updateSegmentFiles(carbonTable, segmentDetails, updateModel.get)

        // this means that the update doesnt have any records to update so no need to do table
        // status file updation.
        if (resultSize == 0) {
          return null
        }
        if (CarbonUpdateUtil.updateTableMetadataStatus(
          segmentDetails,
          carbonTable,
          updateModel.get.updatedTimeStamp + "",
          true,
          new util.ArrayList[Segment](0),
          new util.ArrayList[Segment](segmentFiles), "")) {
        } else {
          LOGGER.error("Data update failed due to failure in table status updation.")
          updateModel.get.executorErrors.errorMsg = errorMessage
          updateModel.get.executorErrors.failureCauses = FailureCauses
            .STATUS_FILE_UPDATION_FAILURE
          return null
        }
      }
      return null
    }
    val uniqueTableStatusId = Option(operationContext.getProperty("uuid")).getOrElse("")
      .asInstanceOf[String]
    if (loadStatus == SegmentStatus.LOAD_FAILURE) {
      // update the load entry in table status file for changing the status to marked for delete
      CarbonLoaderUtil.updateTableStatusForFailure(carbonLoadModel, uniqueTableStatusId)
      LOGGER.info("********starting clean up**********")
      if (carbonLoadModel.isCarbonTransactionalTable) {
        // delete segment is applicable for transactional table
        CarbonLoaderUtil.deleteSegment(carbonLoadModel, carbonLoadModel.getSegmentId.toInt)
        clearDataMapFiles(carbonTable, carbonLoadModel.getSegmentId)
      }
      LOGGER.info("********clean up done**********")
      LOGGER.warn("Cannot write load metadata file as data load failed")
      throw new Exception(errorMessage)
    } else {
      // check if data load fails due to bad record and throw data load failure due to
      // bad record exception
      if (loadStatus == SegmentStatus.LOAD_PARTIAL_SUCCESS &&
          status(0)._2._2.failureCauses == FailureCauses.BAD_RECORDS &&
          carbonLoadModel.getBadRecordsAction.split(",")(1) == LoggerAction.FAIL.name) {
        // update the load entry in table status file for changing the status to marked for delete
        CarbonLoaderUtil.updateTableStatusForFailure(carbonLoadModel, uniqueTableStatusId)
        LOGGER.info("********starting clean up**********")
        if (carbonLoadModel.isCarbonTransactionalTable) {
          // delete segment is applicable for transactional table
          CarbonLoaderUtil.deleteSegment(carbonLoadModel, carbonLoadModel.getSegmentId.toInt)
          clearDataMapFiles(carbonTable, carbonLoadModel.getSegmentId)
        }
        LOGGER.info("********clean up done**********")
        throw new Exception(status(0)._2._2.errorMsg)
      }
      // as no record loaded in new segment, new segment should be deleted
      val newEntryLoadStatus =
        if (carbonLoadModel.isCarbonTransactionalTable &&
            !carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable.isChildDataMap &&
            !carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable.isChildTable &&
            !CarbonLoaderUtil.isValidSegment(carbonLoadModel, carbonLoadModel.getSegmentId.toInt)) {
          LOGGER.warn("Cannot write load metadata file as there is no data to load")
          SegmentStatus.MARKED_FOR_DELETE
        } else {
          loadStatus
        }

      writeDictionary(carbonLoadModel, result, writeAll = false)

      val segmentFileName =
        SegmentFileStore.writeSegmentFile(carbonTable, carbonLoadModel.getSegmentId,
          String.valueOf(carbonLoadModel.getFactTimeStamp))

      SegmentFileStore.updateSegmentFile(
        carbonTable,
        carbonLoadModel.getSegmentId,
        segmentFileName,
        carbonTable.getCarbonTableIdentifier.getTableId,
        new SegmentFileStore(carbonTable.getTablePath, segmentFileName))

      operationContext.setProperty(carbonTable.getTableUniqueName + "_Segment",
        carbonLoadModel.getSegmentId)
      val loadTablePreStatusUpdateEvent: LoadTablePreStatusUpdateEvent =
        new LoadTablePreStatusUpdateEvent(
        carbonTable.getCarbonTableIdentifier,
        carbonLoadModel)
      OperationListenerBus.getInstance().fireEvent(loadTablePreStatusUpdateEvent, operationContext)
      val (done, writtenSegment) =
        updateTableStatus(
          status,
          carbonLoadModel,
          newEntryLoadStatus,
          overwriteTable,
          segmentFileName,
          uniqueTableStatusId)
      val loadTablePostStatusUpdateEvent: LoadTablePostStatusUpdateEvent =
        new LoadTablePostStatusUpdateEvent(carbonLoadModel)
      val commitComplete = try {
        OperationListenerBus.getInstance()
          .fireEvent(loadTablePostStatusUpdateEvent, operationContext)
        true
      } catch {
        case ex: Exception =>
          LOGGER.error("Problem while committing data maps", ex)
          false
      }
      if (!done || !commitComplete) {
        CarbonLoaderUtil.updateTableStatusForFailure(carbonLoadModel, uniqueTableStatusId)
        LOGGER.info("********starting clean up**********")
        if (carbonLoadModel.isCarbonTransactionalTable) {
          // delete segment is applicable for transactional table
          CarbonLoaderUtil.deleteSegment(carbonLoadModel, carbonLoadModel.getSegmentId.toInt)
          // delete corresponding segment file from metadata
          val segmentFile = CarbonTablePath.getSegmentFilesLocation(carbonLoadModel.getTablePath) +
                            File.separator + segmentFileName
          FileFactory.deleteFile(segmentFile, FileFactory.getFileType(segmentFile))
          clearDataMapFiles(carbonTable, carbonLoadModel.getSegmentId)
        }
        LOGGER.info("********clean up done**********")
        LOGGER.error("Data load failed due to failure in table status updation.")
        throw new Exception("Data load failed due to failure in table status updation.")
      }
      if (SegmentStatus.LOAD_PARTIAL_SUCCESS == loadStatus) {
        LOGGER.info("Data load is partially successful for " +
                     s"${ carbonLoadModel.getDatabaseName }.${ carbonLoadModel.getTableName }")
      } else {
        LOGGER.info("Data load is successful for " +
                     s"${ carbonLoadModel.getDatabaseName }.${ carbonLoadModel.getTableName }")
      }

      try {
        // compaction handling
        if (carbonTable.isHivePartitionTable) {
          carbonLoadModel.setFactTimeStamp(System.currentTimeMillis())
        }
        val compactedSegments = new util.ArrayList[String]()
        handleSegmentMerging(sqlContext,
          carbonLoadModel
            .getCopyWithPartition(carbonLoadModel.getCsvHeader, carbonLoadModel.getCsvDelimiter),
          carbonTable,
          compactedSegments,
          operationContext)
        carbonLoadModel.setMergedSegmentIds(compactedSegments)
        writtenSegment
      } catch {
        case e: Exception =>
          LOGGER.error(
            "Auto-Compaction has failed. Ignoring this exception because the" +
            " load is passed.", e)
          writtenSegment
      }
    }
  }

  /**
   * clear datamap files for segment
   */
  private def clearDataMapFiles(carbonTable: CarbonTable, segmentId: String): Unit = {
    try {
      val segments = List(new Segment(segmentId)).asJava
      DataMapStoreManager.getInstance().getAllDataMap(carbonTable).asScala
        .filter(_.getDataMapSchema.isIndexDataMap)
        .foreach(_.deleteDatamapData(segments))
    } catch {
      case ex : Exception =>
        LOGGER.error(s"Failed to clear datamap files for" +
                     s" ${carbonTable.getDatabaseName}.${carbonTable.getTableName}")
    }
  }
  /**
   * Add and update the segment files. In case of update scenario the carbonindex files are written
   * to the same segment so we need to update old segment file. So this ethod writes the latest data
   * to new segment file and merges this file old file to get latest updated files.
   * @param carbonTable
   * @param segmentDetails
   * @return
   */
  private def updateSegmentFiles(
      carbonTable: CarbonTable,
      segmentDetails: util.HashSet[Segment],
      updateModel: UpdateTableModel) = {
    val metadataDetails =
      SegmentStatusManager.readTableStatusFile(
        CarbonTablePath.getTableStatusFilePath(carbonTable.getTablePath))
    val segmentFiles = segmentDetails.asScala.map { seg =>
      val segmentFile =
        metadataDetails.find(_.getLoadName.equals(seg.getSegmentNo)).get.getSegmentFile
      var segmentFiles: Seq[CarbonFile] = Seq.empty[CarbonFile]

      val file = SegmentFileStore.writeSegmentFile(
        carbonTable,
        seg.getSegmentNo,
        String.valueOf(System.currentTimeMillis()))

      if (segmentFile != null) {
        segmentFiles ++= FileFactory.getCarbonFile(
          SegmentFileStore.getSegmentFilePath(carbonTable.getTablePath, segmentFile)) :: Nil
      }
      val updatedSegFile = if (file != null) {
        val carbonFile = FileFactory.getCarbonFile(
          SegmentFileStore.getSegmentFilePath(carbonTable.getTablePath, file))
        segmentFiles ++= carbonFile :: Nil

        val mergedSegFileName = SegmentFileStore.genSegmentFileName(
          seg.getSegmentNo,
          updateModel.updatedTimeStamp.toString)
        SegmentFileStore.mergeSegmentFiles(
          mergedSegFileName,
          CarbonTablePath.getSegmentFilesLocation(carbonTable.getTablePath),
          segmentFiles.toArray)
        carbonFile.delete()
        mergedSegFileName + CarbonTablePath.SEGMENT_EXT
      } else {
        null
      }

      new Segment(seg.getSegmentNo, updatedSegFile)
    }.filter(_.getSegmentFileName != null).asJava
    segmentFiles
  }

  /**
   * If data load is triggered by UPDATE query, this func will execute the update
   * TODO: move it to a separate update command
   */
  private def loadDataFrameForUpdate(
      sqlContext: SQLContext,
      dataFrame: Option[DataFrame],
      carbonLoadModel: CarbonLoadModel,
      updateModel: Option[UpdateTableModel],
      carbonTable: CarbonTable,
      hadoopConf: Configuration): Array[List[(String, (LoadMetadataDetails, ExecutionErrors))]] = {
    val segmentUpdateParallelism = CarbonProperties.getInstance().getParallelismForSegmentUpdate

    val updateRdd = dataFrame.get.rdd

    // return directly if no rows to update
    val noRowsToUpdate = updateRdd.isEmpty()
    if (noRowsToUpdate) {
      Array[List[(String, (LoadMetadataDetails, ExecutionErrors))]]()
    } else {
      // splitting as (key, value) i.e., (segment, updatedRows)
      val keyRDD = updateRdd.map(row =>
        (row.get(row.size - 1).toString, Row(row.toSeq.slice(0, row.size - 1): _*)))

      val loadMetadataDetails = SegmentStatusManager.readLoadMetadata(
        carbonTable.getMetadataPath)
        .filter(lmd => lmd.getSegmentStatus.equals(SegmentStatus.LOAD_PARTIAL_SUCCESS) ||
                       lmd.getSegmentStatus.equals(SegmentStatus.SUCCESS))
      val segments = loadMetadataDetails.map(f => new Segment(f.getLoadName, f.getSegmentFile))
      val segmentIdIndex = segments.map(_.getSegmentNo).zipWithIndex.toMap
      val segmentId2maxTaskNo = segments.map { seg =>
        (seg.getSegmentNo,
          CarbonUpdateUtil.getLatestTaskIdForSegment(seg, carbonLoadModel.getTablePath))
      }.toMap

      class SegmentPartitioner(segIdIndex: Map[String, Int], parallelism: Int)
        extends org.apache.spark.Partitioner {
        override def numPartitions: Int = segmentIdIndex.size * parallelism

        override def getPartition(key: Any): Int = {
          val segId = key.asInstanceOf[String]
          segmentIdIndex(segId) * parallelism + Random.nextInt(parallelism)
        }
      }

      val partitionByRdd = keyRDD.partitionBy(
        new SegmentPartitioner(segmentIdIndex, segmentUpdateParallelism))

      // because partitionId=segmentIdIndex*parallelism+RandomPart and RandomPart<parallelism,
      // so segmentIdIndex=partitionId/parallelism, this has been verified.
      val conf = SparkSQLUtil.broadCastHadoopConf(sqlContext.sparkSession.sparkContext, hadoopConf)
      partitionByRdd.map(_._2).mapPartitions { partition =>
        ThreadLocalSessionInfo.setConfigurationToCurrentThread(conf.value.value)
        val partitionId = TaskContext.getPartitionId()
        val segIdIndex = partitionId / segmentUpdateParallelism
        val randomPart = partitionId - segIdIndex * segmentUpdateParallelism
        val segId = segments(segIdIndex)
        val newTaskNo = segmentId2maxTaskNo(segId.getSegmentNo) + randomPart + 1
        List(triggerDataLoadForSegment(
          carbonLoadModel,
          updateModel,
          segId.getSegmentNo,
          newTaskNo,
          partition).toList).toIterator
      }.collect()
    }
  }

  /**
   * TODO: move it to a separate update command
   */
  private def triggerDataLoadForSegment(
      carbonLoadModel: CarbonLoadModel,
      updateModel: Option[UpdateTableModel],
      key: String,
      taskNo: Long,
      iter: Iterator[Row]): Iterator[(String, (LoadMetadataDetails, ExecutionErrors))] = {
    val rddResult = new updateResultImpl()
    val LOGGER = LogServiceFactory.getLogService(this.getClass.getName)
    val resultIter = new Iterator[(String, (LoadMetadataDetails, ExecutionErrors))] {
      val loadMetadataDetails = new LoadMetadataDetails
      val executionErrors = ExecutionErrors(FailureCauses.NONE, "")
      var uniqueLoadStatusId = ""
      try {
        val segId = key
        val index = taskNo
        uniqueLoadStatusId = carbonLoadModel.getTableName +
                             CarbonCommonConstants.UNDERSCORE +
                             (index + "_0")

        loadMetadataDetails.setPartitionCount(CarbonTablePath.DEPRECATED_PARTITION_ID)
        loadMetadataDetails.setLoadName(segId)
        loadMetadataDetails.setSegmentStatus(SegmentStatus.LOAD_FAILURE)
        carbonLoadModel.setSegmentId(segId)
        carbonLoadModel.setTaskNo(String.valueOf(index))
        carbonLoadModel.setFactTimeStamp(updateModel.get.updatedTimeStamp)

        loadMetadataDetails.setSegmentStatus(SegmentStatus.SUCCESS)
        UpdateDataLoad.DataLoadForUpdate(segId,
          index,
          iter,
          carbonLoadModel,
          loadMetadataDetails)
      } catch {
        case e: NoRetryException =>
          loadMetadataDetails
            .setSegmentStatus(SegmentStatus.LOAD_PARTIAL_SUCCESS)
          executionErrors.failureCauses = FailureCauses.BAD_RECORDS
          executionErrors.errorMsg = e.getMessage
          LOGGER.info("Bad Record Found")
        case e: Exception =>
          LOGGER.info("DataLoad failure")
          LOGGER.error(e)
          throw e
      }

      var finished = false

      override def hasNext: Boolean = !finished

      override def next(): (String, (LoadMetadataDetails, ExecutionErrors)) = {
        finished = true
        rddResult
          .getKey(uniqueLoadStatusId,
            (loadMetadataDetails, executionErrors))
      }
    }
    resultIter
  }

  /**
   * Trigger to write dictionary files
   */
  private def writeDictionary(carbonLoadModel: CarbonLoadModel,
      result: Option[DictionaryServer], writeAll: Boolean): Unit = {
    // write dictionary file
    val uniqueTableName: String =
      CarbonTable.buildUniqueName(carbonLoadModel.getDatabaseName, carbonLoadModel.getTableName)
    result match {
      case Some(server) =>
        try {
          server.writeTableDictionary(carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable
            .getCarbonTableIdentifier.getTableId)
        } catch {
          case _: Exception =>
            LOGGER.error(s"Error while writing dictionary file for $uniqueTableName")
            throw new Exception("Dataload failed due to error while writing dictionary file!")
        }
      case _ =>
    }
  }

  /**
   * Trigger compaction after data load
   */
  def handleSegmentMerging(
      sqlContext: SQLContext,
      carbonLoadModel: CarbonLoadModel,
      carbonTable: CarbonTable,
      compactedSegments: java.util.List[String],
      operationContext: OperationContext): Unit = {
    LOGGER.info(s"compaction need status is" +
                s" ${ CarbonDataMergerUtil.checkIfAutoLoadMergingRequired(carbonTable) }")
    if (!carbonTable.isChildDataMap &&
        CarbonDataMergerUtil.checkIfAutoLoadMergingRequired(carbonTable)) {
      val compactionSize = 0
      val isCompactionTriggerByDDl = false
      val compactionModel = CompactionModel(
        compactionSize,
        CompactionType.MINOR,
        carbonTable,
        isCompactionTriggerByDDl,
        CarbonFilters.getCurrentPartitions(sqlContext.sparkSession,
          TableIdentifier(carbonTable.getTableName,
            Some(carbonTable.getDatabaseName))), None)
      var storeLocation = ""
      val configuredStore = Util.getConfiguredLocalDirs(SparkEnv.get.conf)
      if (null != configuredStore && configuredStore.nonEmpty) {
        storeLocation = configuredStore(Random.nextInt(configuredStore.length))
      }
      if (storeLocation == null) {
        storeLocation = System.getProperty("java.io.tmpdir")
      }
      storeLocation = storeLocation + "/carbonstore/" + System.nanoTime()

      val isConcurrentCompactionAllowed = CarbonProperties.getInstance().getProperty(
        CarbonCommonConstants.ENABLE_CONCURRENT_COMPACTION,
        CarbonCommonConstants.DEFAULT_ENABLE_CONCURRENT_COMPACTION
      ).equalsIgnoreCase("true")

      if (!isConcurrentCompactionAllowed) {
        handleCompactionForSystemLocking(sqlContext,
          carbonLoadModel,
          storeLocation,
          CompactionType.MINOR,
          carbonTable,
          compactedSegments,
          compactionModel,
          operationContext
        )
      } else {
        val lock = CarbonLockFactory.getCarbonLockObj(
          carbonTable.getAbsoluteTableIdentifier,
          LockUsage.COMPACTION_LOCK)
        val updateLock = CarbonLockFactory.getCarbonLockObj(carbonTable
          .getAbsoluteTableIdentifier, LockUsage.UPDATE_LOCK)
        try {
          if (updateLock.lockWithRetries(3, 3)) {
            if (lock.lockWithRetries()) {
              LOGGER.info("Acquired the compaction lock.")
              startCompactionThreads(sqlContext,
                carbonLoadModel,
                storeLocation,
                compactionModel,
                lock,
                compactedSegments,
                operationContext
              )
            } else {
              LOGGER.error("Not able to acquire the compaction lock for table " +
                           s"${ carbonLoadModel.getDatabaseName }.${ carbonLoadModel.getTableName}")
            }
          } else {
            throw new ConcurrentOperationException(carbonTable, "update", "compaction")
          }
        } catch {
          case e: Exception =>
            LOGGER.error(s"Exception in start compaction thread.", e)
            lock.unlock()
            throw e
        } finally {
          updateLock.unlock()
        }
      }
    }
  }

  /**
   * Update table status file after data loading
   * @param status status collected from each task
   * @param carbonLoadModel load model used for loading
   * @param newEntryLoadStatus segment status to set in the metadata
   * @param overwriteTable true the operation is overwrite
   * @param segmentFileName segment file name
   * @param uuid uuid for the table status file name
   * @return whether operation success and
   *         the segment metadata that written into the segment status file
   */
  private def updateTableStatus(
      status: Array[(String, (LoadMetadataDetails, ExecutionErrors))],
      carbonLoadModel: CarbonLoadModel,
      newEntryLoadStatus: SegmentStatus,
      overwriteTable: Boolean,
      segmentFileName: String,
      uuid: String = ""): (Boolean, LoadMetadataDetails) = {
    val carbonTable = carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable
    val metadataDetails = if (status != null && status.size > 0 && status(0) != null) {
      status(0)._2._1
    } else {
      new LoadMetadataDetails
    }
    metadataDetails.setSegmentFile(segmentFileName)
    CarbonLoaderUtil.populateNewLoadMetaEntry(
        metadataDetails,
        newEntryLoadStatus,
        carbonLoadModel.getFactTimeStamp,
    true)
    CarbonLoaderUtil
      .addDataIndexSizeIntoMetaEntry(metadataDetails, carbonLoadModel.getSegmentId, carbonTable)

    if (!carbonLoadModel.isCarbonTransactionalTable && overwriteTable) {
      CarbonLoaderUtil.deleteNonTransactionalTableForInsertOverwrite(carbonLoadModel)
    }
    val done = CarbonLoaderUtil.recordNewLoadMetadata(metadataDetails, carbonLoadModel, false,
      overwriteTable, uuid)
    if (!done) {
      val errorMessage = s"Dataload failed due to failure in table status updation for" +
                         s" ${carbonLoadModel.getTableName}"
      LOGGER.error(errorMessage)
      throw new Exception(errorMessage)
    } else {
      DataMapStatusManager.disableAllLazyDataMaps(carbonTable)
      if (overwriteTable) {
        val allDataMapSchemas = DataMapStoreManager.getInstance
          .getDataMapSchemasOfTable(carbonTable).asScala
          .filter(dataMapSchema => null != dataMapSchema.getRelationIdentifier &&
                                   !dataMapSchema.isIndexDataMap).asJava
        if (!allDataMapSchemas.isEmpty) {
          DataMapStatusManager.truncateDataMap(allDataMapSchemas)
        }
      }
    }
    (done, metadataDetails)
  }

  /**
   * repartition the input data for partition table.
   */
  private def repartitionInputData(
      sqlContext: SQLContext,
      dataFrame: Option[DataFrame],
      carbonLoadModel: CarbonLoadModel,
      hadoopConf: Configuration): RDD[Row] = {
    val carbonTable = carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable
    val partitionInfo = carbonTable.getPartitionInfo(carbonTable.getTableName)
    val partitionColumn = partitionInfo.getColumnSchemaList.get(0).getColumnName
    val partitionColumnDataType = partitionInfo.getColumnSchemaList.get(0).getDataType
    val columns = carbonLoadModel.getCsvHeaderColumns
    var partitionColumnIndex = -1
    breakable {
      for (i <- 0 until columns.length) {
        if (partitionColumn.equalsIgnoreCase(columns(i))) {
          partitionColumnIndex = i
          break
        }
      }
    }
    if (partitionColumnIndex == -1) {
      throw new DataLoadingException("Partition column not found.")
    }

    val specificTimestampFormat = carbonLoadModel.getTimestampformat
    val specificDateFormat = carbonLoadModel.getDateFormat
    val timeStampFormat =
      if (specificTimestampFormat != null && !specificTimestampFormat.trim.isEmpty) {
        new SimpleDateFormat(specificTimestampFormat)
      } else {
        val timestampFormatString = CarbonProperties.getInstance().getProperty(
          CarbonCommonConstants.CARBON_TIMESTAMP_FORMAT,
          CarbonCommonConstants.CARBON_TIMESTAMP_DEFAULT_FORMAT)
        new SimpleDateFormat(timestampFormatString)
      }

    val dateFormat = if (specificDateFormat != null && !specificDateFormat.trim.isEmpty) {
      new SimpleDateFormat(specificDateFormat)
    } else {
      val dateFormatString = CarbonProperties.getInstance().getProperty(CarbonCommonConstants
        .CARBON_DATE_FORMAT, CarbonCommonConstants.CARBON_DATE_DEFAULT_FORMAT)
      new SimpleDateFormat(dateFormatString)
    }
    dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"))

    // generate RDD[(K, V)] to use the partitionBy method of PairRDDFunctions
    val inputRDD: RDD[(String, Row)] = if (dataFrame.isDefined) {
      // input data from DataFrame
      val complexDelimiters = carbonLoadModel.getComplexDelimiters
      val serializationNullFormat =
        carbonLoadModel.getSerializationNullFormat.split(CarbonCommonConstants.COMMA, 2)(1)
      dataFrame.get.rdd.map { row =>
        if (null != row && row.length > partitionColumnIndex &&
            null != row.get(partitionColumnIndex)) {
          (CarbonScalaUtil.getString(row.get(partitionColumnIndex), serializationNullFormat,
            complexDelimiters, timeStampFormat, dateFormat), row)
        } else {
          (null, row)
        }
      }
    } else {
      // input data from csv files
      CommonUtil.configureCSVInputFormat(hadoopConf, carbonLoadModel)
      hadoopConf.set(FileInputFormat.INPUT_DIR, carbonLoadModel.getFactFilePath)
      val columnCount = columns.length
      val jobConf = new JobConf(hadoopConf)
      SparkHadoopUtil.get.addCredentials(jobConf)
      new NewHadoopRDD[NullWritable, StringArrayWritable](
        sqlContext.sparkContext,
        classOf[CSVInputFormat],
        classOf[NullWritable],
        classOf[StringArrayWritable],
        jobConf
      ).map { currentRow =>
        if (null == currentRow || null == currentRow._2) {
          val row = new StringArrayRow(new Array[String](columnCount))
          (null, row)
        } else {
          val row = new StringArrayRow(new Array[String](columnCount))
          val values = currentRow._2.get()
          if (values != null && values.length > partitionColumnIndex) {
            (currentRow._2.get()(partitionColumnIndex), row.setValues(currentRow._2.get()))
          } else {
            (null, row.setValues(currentRow._2.get()))
          }
        }
      }
    }

    val partitioner = PartitionFactory.getPartitioner(partitionInfo)
    if (partitionColumnDataType == DataTypes.STRING) {
      if (partitionInfo.getPartitionType == PartitionType.RANGE) {
        inputRDD.map { row => (ByteUtil.toBytes(row._1), row._2) }
          .partitionBy(partitioner)
          .map(_._2)
      } else {
        inputRDD.partitionBy(partitioner)
          .map(_._2)
      }
    } else {
      inputRDD.map { row =>
        (PartitionUtil.getDataBasedOnDataType(row._1, partitionColumnDataType, timeStampFormat,
          dateFormat), row._2)
      }
        .partitionBy(partitioner)
        .map(_._2)
    }
  }

  /**
   * Execute load process for partition table
   */
  private def loadDataForPartitionTable(
      sqlContext: SQLContext,
      dataFrame: Option[DataFrame],
      carbonLoadModel: CarbonLoadModel,
      hadoopConf: Configuration
  ): Array[(String, (LoadMetadataDetails, ExecutionErrors))] = {
    try {
      val rdd = repartitionInputData(sqlContext, dataFrame, carbonLoadModel, hadoopConf)
      new PartitionTableDataLoaderRDD(
        sqlContext.sparkSession,
        new DataLoadResultImpl(),
        carbonLoadModel,
        rdd
      ).collect()
    } catch {
      case ex: Exception =>
        LOGGER.error("load data failed for partition table", ex)
        throw ex
    }
  }

  /**
   * Execute load process to load from input dataframe
   */
  private def loadDataFrame(
      sqlContext: SQLContext,
      dataFrame: Option[DataFrame],
      carbonLoadModel: CarbonLoadModel
  ): Array[(String, (LoadMetadataDetails, ExecutionErrors))] = {
    try {
      val rdd = dataFrame.get.rdd

      val nodeNumOfData = rdd.partitions.flatMap[String, Array[String]] { p =>
        DataLoadPartitionCoalescer.getPreferredLocs(rdd, p).map(_.host)
      }.distinct.length
      val nodes = DistributionUtil.ensureExecutorsByNumberAndGetNodeList(
        nodeNumOfData,
        sqlContext.sparkContext)
      val newRdd = new DataLoadCoalescedRDD[Row](sqlContext.sparkSession, rdd, nodes.toArray
        .distinct)

      new NewDataFrameLoaderRDD(
        sqlContext.sparkSession,
        new DataLoadResultImpl(),
        carbonLoadModel,
        newRdd
      ).collect()
    } catch {
      case ex: Exception =>
        LOGGER.error("load data frame failed", ex)
        throw ex
    }
  }

  /**
   * Execute load process to load from input file path specified in `carbonLoadModel`
   */
  private def loadDataFile(
      sqlContext: SQLContext,
      carbonLoadModel: CarbonLoadModel,
      hadoopConf: Configuration
  ): Array[(String, (LoadMetadataDetails, ExecutionErrors))] = {
    /*
     * when data load handle by node partition
     * 1)clone the hadoop configuration,and set the file path to the configuration
     * 2)use org.apache.hadoop.mapreduce.lib.input.TextInputFormat to get splits,size info
     * 3)use CarbonLoaderUtil.nodeBlockMapping to get mapping info of node and block,
     *   for locally writing carbondata files(one file one block) in nodes
     * 4)use NewCarbonDataLoadRDD to load data and write to carbondata files
     */
    // FileUtils will skip file which is no csv, and return all file path which split by ','
    val filePaths = carbonLoadModel.getFactFilePath
    hadoopConf.set(FileInputFormat.INPUT_DIR, filePaths)
    hadoopConf.set(FileInputFormat.INPUT_DIR_RECURSIVE, "true")
    hadoopConf.set("io.compression.codecs",
      """org.apache.hadoop.io.compress.GzipCodec,
             org.apache.hadoop.io.compress.DefaultCodec,
             org.apache.hadoop.io.compress.BZip2Codec""".stripMargin)

    CommonUtil.configSplitMaxSize(sqlContext.sparkContext, filePaths, hadoopConf)
    val jobConf = new JobConf(hadoopConf)
    SparkHadoopUtil.get.addCredentials(jobConf)
    val inputFormat = new org.apache.hadoop.mapreduce.lib.input.TextInputFormat
    val jobContext = new Job(jobConf)
    val rawSplits = inputFormat.getSplits(jobContext).toArray
    val blockList = rawSplits.map { inputSplit =>
      val fileSplit = inputSplit.asInstanceOf[FileSplit]
      new TableBlockInfo(fileSplit.getPath.toString,
        fileSplit.getStart, "1",
        fileSplit.getLocations, fileSplit.getLength, ColumnarFormatVersion.V1, null
      ).asInstanceOf[Distributable]
    }
    // group blocks to nodes, tasks
    val startTime = System.currentTimeMillis
    val activeNodes = DistributionUtil
      .ensureExecutorsAndGetNodeList(blockList, sqlContext.sparkContext)
    val skewedDataOptimization = CarbonProperties.getInstance()
      .isLoadSkewedDataOptimizationEnabled()
    // get user ddl input the node loads the smallest amount of data
    val carbonTable = carbonLoadModel.getCarbonDataLoadSchema.getCarbonTable
    var loadMinSize = carbonLoadModel.getLoadMinSize()
    if (loadMinSize.equalsIgnoreCase(CarbonCommonConstants.CARBON_LOAD_MIN_SIZE_INMB_DEFAULT)) {
      loadMinSize = carbonTable.getTableInfo.getFactTable.getTableProperties.asScala
        .getOrElse(CarbonCommonConstants.CARBON_LOAD_MIN_SIZE_INMB,
          CarbonCommonConstants.CARBON_LOAD_MIN_SIZE_INMB_DEFAULT)
    }

    val blockAssignStrategy = if (!loadMinSize.equalsIgnoreCase(
      CarbonCommonConstants.CARBON_LOAD_MIN_SIZE_INMB_DEFAULT)) {
      CarbonLoaderUtil.BlockAssignmentStrategy.NODE_MIN_SIZE_FIRST
    } else if (skewedDataOptimization) {
      CarbonLoaderUtil.BlockAssignmentStrategy.BLOCK_SIZE_FIRST
    } else {
      CarbonLoaderUtil.BlockAssignmentStrategy.BLOCK_NUM_FIRST
    }
    LOGGER.info(s"Allocating block to nodes using strategy: $blockAssignStrategy")

    val nodeBlockMapping = CarbonLoaderUtil.nodeBlockMapping(blockList.toSeq.asJava, -1,
      activeNodes.toList.asJava, blockAssignStrategy, loadMinSize).asScala.toSeq
    val timeElapsed: Long = System.currentTimeMillis - startTime
    LOGGER.info("Total Time taken in block allocation: " + timeElapsed)
    LOGGER.info(s"Total no of blocks: ${ blockList.length }, " +
                s"No.of Nodes: ${nodeBlockMapping.size}")
    var str = ""
    nodeBlockMapping.foreach { entry =>
      val tableBlock = entry._2
      val totalSize = tableBlock.asScala.map(_.asInstanceOf[TableBlockInfo].getBlockLength).sum
      str = str + "#Node: " + entry._1 + ", no.of.blocks: " + tableBlock.size() +
            f", totalsize.of.blocks: ${totalSize * 0.1 * 10 / 1024 /1024}%.2fMB"
      tableBlock.asScala.foreach(tableBlockInfo =>
        if (!tableBlockInfo.getLocations.exists(hostentry =>
          hostentry.equalsIgnoreCase(entry._1)
        )) {
          str = str + " , mismatch locations: " + tableBlockInfo.getLocations
            .foldLeft("")((a, b) => a + "," + b)
        }
      )
      str = str + "\n"
    }
    LOGGER.info(str)
    val blocksGroupBy: Array[(String, Array[BlockDetails])] = nodeBlockMapping.map { entry =>
      val blockDetailsList =
        entry._2.asScala.map(distributable => {
          val tableBlock = distributable.asInstanceOf[TableBlockInfo]
          new BlockDetails(new Path(tableBlock.getFilePath),
            tableBlock.getBlockOffset, tableBlock.getBlockLength, tableBlock.getLocations
          )
        }).toArray
      (entry._1, blockDetailsList)
    }.toArray

    new NewCarbonDataLoadRDD(
      sqlContext.sparkSession,
      new DataLoadResultImpl(),
      carbonLoadModel,
      blocksGroupBy
    ).collect()
  }
}
