HeartSaVioR commented on a change in pull request #26416: [SPARK-29779][CORE] Compact old event log files and cleanup URL: https://github.com/apache/spark/pull/26416#discussion_r357449041
########## File path: core/src/main/scala/org/apache/spark/deploy/history/EventLogFileCompactor.scala ########## @@ -0,0 +1,157 @@ +/* + * 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.deploy.history + +import java.io.IOException +import java.net.URI + +import org.apache.hadoop.conf.Configuration +import org.apache.hadoop.fs.{FileStatus, FileSystem, Path} + +import org.apache.spark.SparkConf +import org.apache.spark.internal.Logging +import org.apache.spark.internal.config.EVENT_LOG_ROLLING_MAX_FILES_TO_RETAIN +import org.apache.spark.scheduler._ + +/** + * This class compacts the old event log files into one compact file, via two phases reading: + * + * 1) Initialize available [[EventFilterBuilder]] instances, and replay the old event log files with + * builders, so that these builders can gather the information to create [[EventFilter]] instances. + * 2) Initialize [[EventFilter]] instances from [[EventFilterBuilder]] instances, and replay the + * old event log files with filters. Rewrite the events to the compact file which the filters decide + * to accept. + * + * This class assumes caller will provide the sorted list of files which are sorted by the index of + * event log file - caller should keep in mind that this class doesn't care about the semantic of + * ordering. + * + * When compacting the files, the range of compaction for given file list is determined as: + * (rightmost compact file ~ the file where there're `maxFilesToRetain` files on the right side) + * + * If there's no compact file in the list, it starts from the first file. If there're not enough + * files after rightmost compact file, compaction will be skipped. + */ +class EventLogFileCompactor( + sparkConf: SparkConf, + hadoopConf: Configuration, + fs: FileSystem) extends Logging { + + private val maxFilesToRetain: Int = sparkConf.get(EVENT_LOG_ROLLING_MAX_FILES_TO_RETAIN) + + def compact(eventLogFiles: Seq[FileStatus]): Seq[FileStatus] = { + if (eventLogFiles.length <= maxFilesToRetain) { + return eventLogFiles + } + + if (EventLogFileWriter.isCompacted(eventLogFiles.last.getPath)) { + return Seq(eventLogFiles.last) + } + + val (filesToCompact, filesToRetain) = findFilesToCompact(eventLogFiles) + if (filesToCompact.isEmpty) { + filesToRetain + } else { + val builders = EventFilterBuilder.initializeBuilders(fs, filesToCompact.map(_.getPath)) + + val rewriter = new FilteredEventLogFileRewriter(sparkConf, hadoopConf, fs, + builders.map(_.createFilter())) + val compactedPath = rewriter.rewrite(filesToCompact) + + cleanupCompactedFiles(filesToCompact) + + fs.getFileStatus(new Path(compactedPath)) :: filesToRetain.toList + } + } + + private def cleanupCompactedFiles(files: Seq[FileStatus]): Unit = { + files.foreach { file => + var deleted = false + try { + deleted = fs.delete(file.getPath, true) + } catch { + case _: IOException => + } + if (!deleted) { + logWarning(s"Failed to remove ${file.getPath} / skip removing.") + } + } + } + + private def findFilesToCompact( + eventLogFiles: Seq[FileStatus]): (Seq[FileStatus], Seq[FileStatus]) = { + val files = RollingEventLogFilesFileReader.dropBeforeLastCompactFile(eventLogFiles) + if (files.length > maxFilesToRetain) { + (files.dropRight(maxFilesToRetain), files.takeRight(maxFilesToRetain)) + } else { + (Seq.empty, files) + } + } +} + +/** + * This class rewrites the event log files into one compact file: the compact file will only + * contain the events which pass the filters. Events will be dropped only when all filters + * decide to reject the event or don't mind about the event. Otherwise, the original line for + * the event is written to the compact file as it is. + */ +class FilteredEventLogFileRewriter( + sparkConf: SparkConf, + hadoopConf: Configuration, + fs: FileSystem, + filters: Seq[EventFilter]) { + + def rewrite(eventLogFiles: Seq[FileStatus]): String = { + require(eventLogFiles.nonEmpty) + + val lastIndexEventLogPath = eventLogFiles.last.getPath + val logWriter = new CompactedEventLogFileWriter(lastIndexEventLogPath, "dummy", None, + lastIndexEventLogPath.getParent.toUri, sparkConf, hadoopConf) + + logWriter.start() + eventLogFiles.foreach { file => + EventFilter.applyFilterToFile(fs, filters, file.getPath) { case (line, _) => Review comment: I'm seeing both forms (my patch and suggestion) in Spark codebase, but I agree the form in suggestion is clearer and more readable. Let me reflect it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
