All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.spark.HoodieHadoopFSUtils.scala Maven / Gradle / Ivy

There is a newer version: 1.0.0-beta2
Show newest version
/*
 * 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.spark

import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.fs.viewfs.ViewFileSystem
import org.apache.hadoop.fs._
import org.apache.hadoop.hdfs.DistributedFileSystem
import org.apache.spark.internal.Logging
import org.apache.spark.metrics.source.HiveCatalogMetrics
import org.apache.spark.util.SerializableConfiguration

import java.io.FileNotFoundException
import scala.collection.mutable

/**
 * NOTE: This method class is replica of HadoopFSUtils from Spark 3.2.1, with the following adjustments
 *
 *    - Filtering out of the listed files is adjusted to include files starting w/ "." (to include Hoodie Delta Log
 *    files)
 */
object HoodieHadoopFSUtils extends Logging {
  /**
   * Lists a collection of paths recursively. Picks the listing strategy adaptively depending
   * on the number of paths to list.
   *
   * This may only be called on the driver.
   *
   * @param sc                   Spark context used to run parallel listing.
   * @param paths                Input paths to list
   * @param hadoopConf           Hadoop configuration
   * @param filter               Path filter used to exclude leaf files from result
   * @param ignoreMissingFiles   Ignore missing files that happen during recursive listing
   *                             (e.g., due to race conditions)
   * @param ignoreLocality       Whether to fetch data locality info when listing leaf files. If false,
   *                             this will return `FileStatus` without `BlockLocation` info.
   * @param parallelismThreshold The threshold to enable parallelism. If the number of input paths
   *                             is smaller than this value, this will fallback to use
   *                             sequential listing.
   * @param parallelismMax       The maximum parallelism for listing. If the number of input paths is
   *                             larger than this value, parallelism will be throttled to this value
   *                             to avoid generating too many tasks.
   * @return for each input path, the set of discovered files for the path
   */
  def parallelListLeafFiles(sc: SparkContext,
                            paths: Seq[Path],
                            hadoopConf: Configuration,
                            filter: PathFilter,
                            ignoreMissingFiles: Boolean,
                            ignoreLocality: Boolean,
                            parallelismThreshold: Int,
                            parallelismMax: Int): Seq[(Path, Seq[FileStatus])] = {
    parallelListLeafFilesInternal(sc, paths, hadoopConf, filter, isRootLevel = true,
      ignoreMissingFiles, ignoreLocality, parallelismThreshold, parallelismMax)
  }

  // scalastyle:off parameter.number
  private def parallelListLeafFilesInternal(sc: SparkContext,
                                            paths: Seq[Path],
                                            hadoopConf: Configuration,
                                            filter: PathFilter,
                                            isRootLevel: Boolean,
                                            ignoreMissingFiles: Boolean,
                                            ignoreLocality: Boolean,
                                            parallelismThreshold: Int,
                                            parallelismMax: Int): Seq[(Path, Seq[FileStatus])] = {

    // Short-circuits parallel listing when serial listing is likely to be faster.
    if (paths.size <= parallelismThreshold) {
      // scalastyle:off return
      return paths.map { path =>
        val leafFiles = listLeafFiles(
          path,
          hadoopConf,
          filter,
          Some(sc),
          ignoreMissingFiles = ignoreMissingFiles,
          ignoreLocality = ignoreLocality,
          isRootPath = isRootLevel,
          parallelismThreshold = parallelismThreshold,
          parallelismMax = parallelismMax)
        (path, leafFiles)
      }
      // scalastyle:on return
    }

    logInfo(s"Listing leaf files and directories in parallel under ${paths.length} paths." +
      s" The first several paths are: ${paths.take(10).mkString(", ")}.")
    HiveCatalogMetrics.incrementParallelListingJobCount(1)

    val serializableConfiguration = new SerializableConfiguration(hadoopConf)
    val serializedPaths = paths.map(_.toString)

    // Set the number of parallelism to prevent following file listing from generating many tasks
    // in case of large #defaultParallelism.
    val numParallelism = Math.min(paths.size, parallelismMax)

    val previousJobDescription = sc.getLocalProperty(SparkContext.SPARK_JOB_DESCRIPTION)
    val statusMap = try {
      val description = paths.size match {
        case 0 =>
          "Listing leaf files and directories 0 paths"
        case 1 =>
          s"Listing leaf files and directories for 1 path:
${paths(0)}" case s => s"Listing leaf files and directories for $s paths:
${paths(0)}, ..." } sc.setJobDescription(description) sc .parallelize(serializedPaths, numParallelism) .mapPartitions { pathStrings => val hadoopConf = serializableConfiguration.value pathStrings.map(new Path(_)).toSeq.map { path => val leafFiles = listLeafFiles( path = path, hadoopConf = hadoopConf, filter = filter, contextOpt = None, // Can't execute parallel scans on workers ignoreMissingFiles = ignoreMissingFiles, ignoreLocality = ignoreLocality, isRootPath = isRootLevel, parallelismThreshold = Int.MaxValue, parallelismMax = 0) (path, leafFiles) }.iterator }.map { case (path, statuses) => val serializableStatuses = statuses.map { status => // Turn FileStatus into SerializableFileStatus so we can send it back to the driver val blockLocations = status match { case f: LocatedFileStatus => f.getBlockLocations.map { loc => SerializableBlockLocation( loc.getNames, loc.getHosts, loc.getOffset, loc.getLength) } case _ => Array.empty[SerializableBlockLocation] } SerializableFileStatus( status.getPath.toString, status.getLen, status.isDirectory, status.getReplication, status.getBlockSize, status.getModificationTime, status.getAccessTime, blockLocations) } (path.toString, serializableStatuses) }.collect() } finally { sc.setJobDescription(previousJobDescription) } // turn SerializableFileStatus back to Status statusMap.map { case (path, serializableStatuses) => val statuses = serializableStatuses.map { f => val blockLocations = f.blockLocations.map { loc => new BlockLocation(loc.names, loc.hosts, loc.offset, loc.length) } new LocatedFileStatus( new FileStatus( f.length, f.isDir, f.blockReplication, f.blockSize, f.modificationTime, new Path(f.path)), blockLocations) } (new Path(path), statuses) } } // scalastyle:on parameter.number // scalastyle:off parameter.number /** * Lists a single filesystem path recursively. If a `SparkContext` object is specified, this * function may launch Spark jobs to parallelize listing based on `parallelismThreshold`. * * If sessionOpt is None, this may be called on executors. * * @return all children of path that match the specified filter. */ private def listLeafFiles(path: Path, hadoopConf: Configuration, filter: PathFilter, contextOpt: Option[SparkContext], ignoreMissingFiles: Boolean, ignoreLocality: Boolean, isRootPath: Boolean, parallelismThreshold: Int, parallelismMax: Int): Seq[FileStatus] = { logTrace(s"Listing $path") val fs = path.getFileSystem(hadoopConf) // Note that statuses only include FileStatus for the files and dirs directly under path, // and does not include anything else recursively. val statuses: Array[FileStatus] = try { fs match { // DistributedFileSystem overrides listLocatedStatus to make 1 single call to namenode // to retrieve the file status with the file block location. The reason to still fallback // to listStatus is because the default implementation would potentially throw a // FileNotFoundException which is better handled by doing the lookups manually below. case (_: DistributedFileSystem | _: ViewFileSystem) if !ignoreLocality => val remoteIter = fs.listLocatedStatus(path) new Iterator[LocatedFileStatus]() { def next(): LocatedFileStatus = remoteIter.next def hasNext(): Boolean = remoteIter.hasNext }.toArray case _ => fs.listStatus(path) } } catch { // If we are listing a root path for SQL (e.g. a top level directory of a table), we need to // ignore FileNotFoundExceptions during this root level of the listing because // // (a) certain code paths might construct an InMemoryFileIndex with root paths that // might not exist (i.e. not all callers are guaranteed to have checked // path existence prior to constructing InMemoryFileIndex) and, // (b) we need to ignore deleted root paths during REFRESH TABLE, otherwise we break // existing behavior and break the ability drop SessionCatalog tables when tables' // root directories have been deleted (which breaks a number of Spark's own tests). // // If we are NOT listing a root path then a FileNotFoundException here means that the // directory was present in a previous level of file listing but is absent in this // listing, likely indicating a race condition (e.g. concurrent table overwrite or S3 // list inconsistency). // // The trade-off in supporting existing behaviors / use-cases is that we won't be // able to detect race conditions involving root paths being deleted during // InMemoryFileIndex construction. However, it's still a net improvement to detect and // fail-fast on the non-root cases. For more info see the SPARK-27676 review discussion. case _: FileNotFoundException if isRootPath || ignoreMissingFiles => logWarning(s"The directory $path was not found. Was it deleted very recently?") Array.empty[FileStatus] } val filteredStatuses = statuses.filterNot(status => shouldFilterOutPathName(status.getPath.getName)) val allLeafStatuses = { val (dirs, topLevelFiles) = filteredStatuses.partition(_.isDirectory) val nestedFiles: Seq[FileStatus] = contextOpt match { case Some(context) if dirs.size > parallelismThreshold => parallelListLeafFilesInternal( context, dirs.map(_.getPath), hadoopConf = hadoopConf, filter = filter, isRootLevel = false, ignoreMissingFiles = ignoreMissingFiles, ignoreLocality = ignoreLocality, parallelismThreshold = parallelismThreshold, parallelismMax = parallelismMax ).flatMap(_._2) case _ => dirs.flatMap { dir => listLeafFiles( path = dir.getPath, hadoopConf = hadoopConf, filter = filter, contextOpt = contextOpt, ignoreMissingFiles = ignoreMissingFiles, ignoreLocality = ignoreLocality, isRootPath = false, parallelismThreshold = parallelismThreshold, parallelismMax = parallelismMax) } } val allFiles = topLevelFiles ++ nestedFiles if (filter != null) allFiles.filter(f => filter.accept(f.getPath)) else allFiles } val missingFiles = mutable.ArrayBuffer.empty[String] val resolvedLeafStatuses = allLeafStatuses.flatMap { case f: LocatedFileStatus => Some(f) // NOTE: // // - Although S3/S3A/S3N file system can be quite slow for remote file metadata // operations, calling `getFileBlockLocations` does no harm here since these file system // implementations don't actually issue RPC for this method. // // - Here we are calling `getFileBlockLocations` in a sequential manner, but it should not // be a big deal since we always use to `parallelListLeafFiles` when the number of // paths exceeds threshold. case f if !ignoreLocality => // The other constructor of LocatedFileStatus will call FileStatus.getPermission(), // which is very slow on some file system (RawLocalFileSystem, which is launch a // subprocess and parse the stdout). try { val locations = fs.getFileBlockLocations(f, 0, f.getLen).map { loc => // Store BlockLocation objects to consume less memory if (loc.getClass == classOf[BlockLocation]) { loc } else { new BlockLocation(loc.getNames, loc.getHosts, loc.getOffset, loc.getLength) } } val lfs = new LocatedFileStatus(f.getLen, f.isDirectory, f.getReplication, f.getBlockSize, f.getModificationTime, 0, null, null, null, null, f.getPath, locations) if (f.isSymlink) { lfs.setSymlink(f.getSymlink) } Some(lfs) } catch { case _: FileNotFoundException if ignoreMissingFiles => missingFiles += f.getPath.toString None } case f => Some(f) } if (missingFiles.nonEmpty) { logWarning( s"the following files were missing during file scan:\n ${missingFiles.mkString("\n ")}") } resolvedLeafStatuses } // scalastyle:on parameter.number /** A serializable variant of HDFS's BlockLocation. This is required by Hadoop 2.7. */ private case class SerializableBlockLocation(names: Array[String], hosts: Array[String], offset: Long, length: Long) /** A serializable variant of HDFS's FileStatus. This is required by Hadoop 2.7. */ private case class SerializableFileStatus(path: String, length: Long, isDir: Boolean, blockReplication: Short, blockSize: Long, modificationTime: Long, accessTime: Long, blockLocations: Array[SerializableBlockLocation]) /** Checks if we should filter out this path name. */ def shouldFilterOutPathName(pathName: String): Boolean = { // We filter follow paths: // 1. everything that starts with _ and ., except _common_metadata and _metadata // because Parquet needs to find those metadata files from leaf files returned by this method. // We should refactor this logic to not mix metadata files with data files. // 2. everything that ends with `._COPYING_`, because this is a intermediate state of file. we // should skip this file in case of double reading. val exclude = (pathName.startsWith("_") && !pathName.contains("=")) || pathName.endsWith("._COPYING_") val include = pathName.startsWith("_common_metadata") || pathName.startsWith("_metadata") exclude && !include } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy