Ngone51 commented on a change in pull request #30062: URL: https://github.com/apache/spark/pull/30062#discussion_r516467454
########## File path: common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java ########## @@ -0,0 +1,966 @@ +/* + * 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.network.shuffle; + +import java.io.BufferedOutputStream; +import java.io.DataOutputStream; +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.channels.FileChannel; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.Arrays; +import java.util.Collection; +import java.util.Iterator; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Executor; +import java.util.concurrent.Executors; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Objects; +import com.google.common.base.Preconditions; +import com.google.common.cache.CacheBuilder; +import com.google.common.cache.CacheLoader; +import com.google.common.cache.LoadingCache; +import com.google.common.cache.Weigher; +import com.google.common.collect.Maps; +import io.netty.buffer.ByteBuf; +import io.netty.buffer.Unpooled; +import org.roaringbitmap.RoaringBitmap; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.spark.network.buffer.FileSegmentManagedBuffer; +import org.apache.spark.network.buffer.ManagedBuffer; +import org.apache.spark.network.client.StreamCallbackWithID; +import org.apache.spark.network.protocol.Encoders; +import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo; +import org.apache.spark.network.shuffle.protocol.FinalizeShuffleMerge; +import org.apache.spark.network.shuffle.protocol.MergeStatuses; +import org.apache.spark.network.shuffle.protocol.PushBlockStream; +import org.apache.spark.network.util.JavaUtils; +import org.apache.spark.network.util.NettyUtils; +import org.apache.spark.network.util.TransportConf; + +/** + * An implementation of {@link MergedShuffleFileManager} that provides the most essential shuffle + * service processing logic to support push based shuffle. + */ +public class RemoteBlockPushResolver implements MergedShuffleFileManager { + + private static final Logger logger = LoggerFactory.getLogger(RemoteBlockPushResolver.class); + @VisibleForTesting + static final String MERGE_MANAGER_DIR = "merge_manager"; + + private final ConcurrentMap<String, AppPathsInfo> appsPathInfo; + private final ConcurrentMap<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> partitions; + + private final Executor directoryCleaner; + private final TransportConf conf; + private final int minChunkSize; + private final ErrorHandler.BlockPushErrorHandler errorHandler; + + @SuppressWarnings("UnstableApiUsage") + private final LoadingCache<File, ShuffleIndexInformation> indexCache; + + @SuppressWarnings("UnstableApiUsage") + public RemoteBlockPushResolver(TransportConf conf) { + this.conf = conf; + this.partitions = Maps.newConcurrentMap(); + this.appsPathInfo = Maps.newConcurrentMap(); + this.directoryCleaner = Executors.newSingleThreadExecutor( + // Add `spark` prefix because it will run in NM in Yarn mode. + NettyUtils.createThreadFactory("spark-shuffle-merged-shuffle-directory-cleaner")); + this.minChunkSize = conf.minChunkSizeInMergedShuffleFile(); + CacheLoader<File, ShuffleIndexInformation> indexCacheLoader = + new CacheLoader<File, ShuffleIndexInformation>() { + public ShuffleIndexInformation load(File file) throws IOException { + return new ShuffleIndexInformation(file); + } + }; + indexCache = CacheBuilder.newBuilder() + .maximumWeight(conf.mergedIndexCacheSize()) + .weigher((Weigher<File, ShuffleIndexInformation>) (file, indexInfo) -> indexInfo.getSize()) + .build(indexCacheLoader); + this.errorHandler = new ErrorHandler.BlockPushErrorHandler(); + } + + /** + * Given the appShuffleId and reduceId that uniquely identifies a given shuffle partition of an + * application, retrieves the associated metadata. If not present and the corresponding merged + * shuffle does not exist, initializes the metadata. + */ + private AppShufflePartitionInfo getOrCreateAppShufflePartitionInfo( + AppShuffleId appShuffleId, + int reduceId) { + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!partitions.containsKey(appShuffleId) && dataFile.exists()) { + // If this partition is already finalized then the partitions map will not contain + // the appShuffleId but the data file would exist. In that case the block is considered late. + return null; + } + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + partitions.computeIfAbsent(appShuffleId, id -> Maps.newConcurrentMap()); + return shufflePartitions.computeIfAbsent(reduceId, key -> { + // It only gets here when the key is not present in the map. This could either + // be the first time the merge manager receives a pushed block for a given application + // shuffle partition, or after the merged shuffle file is finalized. We handle these + // two cases accordingly by checking if the file already exists. + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + try { + if (dataFile.exists()) { + return null; + } else { + return new AppShufflePartitionInfo(appShuffleId, reduceId, dataFile, indexFile, metaFile); + } + } catch (IOException e) { + logger.error( + "Cannot create merged shuffle partition with data file {}, index file {}, and " + + "meta file {}", dataFile.getAbsolutePath(), + indexFile.getAbsolutePath(), metaFile.getAbsolutePath()); + throw new RuntimeException( + String.format("Cannot initialize merged shuffle partition for appId %s shuffleId %s " + + "reduceId %s", appShuffleId.appId, appShuffleId.shuffleId, reduceId), e); + } + }); + } + + @Override + public MergedBlockMeta getMergedBlockMeta(String appId, int shuffleId, int reduceId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + if (!indexFile.exists()) { + throw new RuntimeException(String.format( + "Merged shuffle index file %s not found", indexFile.getPath())); + } + int size = (int) indexFile.length(); + // First entry is the zero offset + int numChunks = (size / Long.BYTES) - 1; + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + if (!metaFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle meta file %s not found", + metaFile.getPath())); + } + FileSegmentManagedBuffer chunkBitMaps = + new FileSegmentManagedBuffer(conf, metaFile, 0L, metaFile.length()); + logger.trace( + "{} shuffleId {} reduceId {} num chunks {}", appId, shuffleId, reduceId, numChunks); + return new MergedBlockMeta(numChunks, chunkBitMaps); + } + + @SuppressWarnings("UnstableApiUsage") + @Override + public ManagedBuffer getMergedBlockData(String appId, int shuffleId, int reduceId, int chunkId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!dataFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle data file %s not found", + dataFile.getPath())); + } + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + try { + // If we get here, the merged shuffle file should have been properly finalized. Thus we can + // use the file length to determine the size of the merged shuffle block. + ShuffleIndexInformation shuffleIndexInformation = indexCache.get(indexFile); + ShuffleIndexRecord shuffleIndexRecord = shuffleIndexInformation.getIndex(chunkId); + return new FileSegmentManagedBuffer( + conf, dataFile, shuffleIndexRecord.getOffset(), shuffleIndexRecord.getLength()); + } catch (ExecutionException e) { + throw new RuntimeException(String.format( + "Failed to open merged shuffle index file %s", indexFile.getPath()), e); + } + } + + /** + * The logic here is consistent with + * org.apache.spark.storage.DiskBlockManager#getMergedShuffleFile + */ + private File getFile(String appId, String filename) { + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + File targetFile = ExecutorDiskUtils.getFile(appPathsInfo.activeLocalDirs, + appPathsInfo.subDirsPerLocalDir, filename); + logger.debug("Get merged file {}", targetFile.getAbsolutePath()); + return targetFile; + } + + private File getMergedShuffleDataFile(AppShuffleId appShuffleId, int reduceId) { + String fileName = String.format("%s.data", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, fileName); + } + + private File getMergedShuffleIndexFile(AppShuffleId appShuffleId, int reduceId) { + String indexName = String.format("%s.index", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, indexName); + } + + private File getMergedShuffleMetaFile(AppShuffleId appShuffleId, int reduceId) { + String metaName = String.format("%s.meta", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, metaName); + } + + @Override + public String[] getMergedBlockDirs(String appId) { + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + String[] activeLocalDirs = Preconditions.checkNotNull(appPathsInfo.activeLocalDirs, + "application " + appId + + " active local dirs list has not been updated by any executor registration"); + return activeLocalDirs; + } + + @Override + public void applicationRemoved(String appId, boolean cleanupLocalDirs) { + logger.info("Application {} removed, cleanupLocalDirs = {}", appId, cleanupLocalDirs); + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.remove(appId), + "application " + appId + " is not registered or NM was restarted."); + Iterator<Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>>> iterator = + partitions.entrySet().iterator(); + while (iterator.hasNext()) { + Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> entry = iterator.next(); + AppShuffleId appShuffleId = entry.getKey(); + if (appId.equals(appShuffleId.appId)) { + iterator.remove(); + for (AppShufflePartitionInfo partitionInfo : entry.getValue().values()) { + partitionInfo.closeAllFiles(); + } + } + } + if (cleanupLocalDirs) { + Path[] dirs = Arrays.stream(appPathsInfo.activeLocalDirs) + .map(dir -> Paths.get(dir)).toArray(Path[]::new); + directoryCleaner.execute(() -> deleteExecutorDirs(dirs)); + } + } + + /** + * Serially delete local dirs, executed in a separate thread. + */ + @VisibleForTesting + void deleteExecutorDirs(Path[] dirs) { + for (Path localDir : dirs) { + try { + if (Files.exists(localDir)) { + JavaUtils.deleteRecursively(localDir.toFile()); + logger.debug("Successfully cleaned up directory: {}", localDir); + } + } catch (Exception e) { + logger.error("Failed to delete directory: {}", localDir, e); + } + } + } + + @Override + public StreamCallbackWithID receiveBlockDataAsStream(PushBlockStream msg) { + // Retrieve merged shuffle file metadata + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + AppShufflePartitionInfo partitionInfoBeforeCheck = + getOrCreateAppShufflePartitionInfo(appShuffleId, msg.reduceId); + // Here partitionInfo will be null in 2 cases: + // 1) The request is received for a block that has already been merged, this is possible due + // to the retry logic. + // 2) The request is received after the merged shuffle is finalized, thus is too late. + // + // For case 1, we will drain the data in the channel and just respond success + // to the client. This is required because the response of the previously merged + // block will be ignored by the client, per the logic in RetryingBlockFetcher. + // Note that the netty server should receive data for a given block id only from 1 channel + // at any time. The block should be pushed only from successful maps, thus there should be + // only 1 source for a given block at any time. Although the netty client might retry sending + // this block to the server multiple times, the data of the same block always arrives from the + // same channel thus the server should have already processed the previous request of this + // block before seeing it again in the channel. This guarantees that we can simply just + // check the bitmap to determine if a block is a duplicate or not. + // + // For case 2, we will also drain the data in the channel, but throw an exception in + // {@link org.apache.spark.network.client.StreamCallback#onComplete(String)}. This way, + // the client will be notified of the failure but the channel will remain active. Keeping + // the channel alive is important because the same channel could be reused by multiple map + // tasks in the executor JVM, which belongs to different stages. While one of the shuffles + // in these stages is finalized, the others might still be active. Tearing down the channel + // on the server side will disrupt these other on-going shuffle merges. It's also important + // to notify the client of the failure, so that it can properly halt pushing the remaining + // blocks upon receiving such failures to preserve resources on the server/client side. + // + // Speculative execution would also raise a possible scenario with duplicate blocks. Although + // speculative execution would kill the slower task attempt, leading to only 1 task attempt + // succeeding in the end, there is no guarantee that only one copy of the block will be + // pushed. This is due to our handling of block push process outside of the map task, thus + // it is possible for the speculative task attempt to initiate the block push process before + // getting killed. When this happens, we need to distinguish the duplicate blocks as they + // arrive. More details on this is explained in later comments. + + // Track if the block is received after shuffle merge finalize + final boolean isTooLate = partitionInfoBeforeCheck == null; + // Check if the given block is already merged by checking the bitmap against the given map index + final AppShufflePartitionInfo partitionInfo = partitionInfoBeforeCheck != null + && partitionInfoBeforeCheck.mapTracker.contains(msg.mapIndex) ? null + : partitionInfoBeforeCheck; + if (partitionInfo != null) { + return new PushBlockStreamCallback( + this, msg, appShuffleId, msg.reduceId, msg.mapIndex, partitionInfo); + } else { + // For a duplicate block or a block which is late, respond back with a callback that handles + // them differently. + return new StreamCallbackWithID() { + @Override + public String getID() { + return msg.streamId; + } + + @Override + public void onData(String streamId, ByteBuffer buf) { + // Ignore the requests. It reaches here either when a request is received after the + // shuffle file is finalized or when a request is for a duplicate block. + } + + @Override + public void onComplete(String streamId) { + if (isTooLate) { + // Throw an exception here so the block data is drained from channel and server + // responds RpcFailure to the client. + throw new RuntimeException(String.format("Block %s %s", msg.streamId, + ErrorHandler.BlockPushErrorHandler.TOO_LATE_MESSAGE_SUFFIX)); + } + // For duplicate block that is received before the shuffle merge finalizes, the + // server should respond success to the client. + } + + @Override + public void onFailure(String streamId, Throwable cause) { + } + }; + } + } + + @SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter") + @Override + public MergeStatuses finalizeShuffleMerge(FinalizeShuffleMerge msg) throws IOException { + logger.info("Finalizing shuffle {} from Application {}.", msg.shuffleId, msg.appId); + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + Map<Integer, AppShufflePartitionInfo> shufflePartitions = partitions.get(appShuffleId); + MergeStatuses mergeStatuses; + if (shufflePartitions == null || shufflePartitions.isEmpty()) { + mergeStatuses = + new MergeStatuses(msg.shuffleId, new RoaringBitmap[0], new int[0], new long[0]); + } else { + Collection<AppShufflePartitionInfo> partitionsToFinalize = shufflePartitions.values(); + int totalPartitions = partitionsToFinalize.size(); + RoaringBitmap[] bitmaps = new RoaringBitmap[totalPartitions]; + int[] reduceIds = new int[totalPartitions]; + long[] sizes = new long[totalPartitions]; + Iterator<AppShufflePartitionInfo> partitionsIter = partitionsToFinalize.iterator(); + int idx = 0; + while (partitionsIter.hasNext()) { + AppShufflePartitionInfo partition = partitionsIter.next(); + synchronized (partition) { + // Get rid of any partial block data at the end of the file. This could either + // be due to failure or a request still being processed when the shuffle + // merge gets finalized. + try { + partition.dataChannel.truncate(partition.getPosition()); + if (partition.getPosition() != partition.getLastChunkOffset()) { + partition.updateChunkInfo(partition.getPosition(), partition.lastMergedMapIndex); + } + bitmaps[idx] = partition.mapTracker; + reduceIds[idx] = partition.reduceId; + sizes[idx++] = partition.getPosition(); + } catch (IOException ioe) { + logger.warn("Exception while finalizing shuffle partition {} {} {}", msg.appId, + msg.shuffleId, partition.reduceId, ioe); + } finally { + partition.closeAllFiles(); + // The partition should be removed after the files are written so that any new stream + // for the same reduce partition will see that the data file exists. + partitionsIter.remove(); + } + } + } + mergeStatuses = new MergeStatuses(msg.shuffleId, bitmaps, reduceIds, sizes); + } + partitions.remove(appShuffleId); + logger.info("Finalized shuffle {} from Application {}.", msg.shuffleId, msg.appId); + return mergeStatuses; + } + + @Override + public void registerExecutor(String appId, ExecutorShuffleInfo executorInfo) { + if (logger.isDebugEnabled()) { + logger.debug("register executor with RemoteBlockPushResolver {} local-dirs {} " + + "num sub-dirs {}", appId, Arrays.toString(executorInfo.localDirs), + executorInfo.subDirsPerLocalDir); + } + appsPathInfo.putIfAbsent(appId, new AppPathsInfo()); Review comment: How about we initialize the `activeLocalDirs` in `AppPathsInfo`'s constructor? And then, we don't need a separate `compute` and call `updateActiveLocalDirs()`. ########## File path: common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java ########## @@ -0,0 +1,966 @@ +/* + * 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.network.shuffle; + +import java.io.BufferedOutputStream; +import java.io.DataOutputStream; +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.channels.FileChannel; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.Arrays; +import java.util.Collection; +import java.util.Iterator; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Executor; +import java.util.concurrent.Executors; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Objects; +import com.google.common.base.Preconditions; +import com.google.common.cache.CacheBuilder; +import com.google.common.cache.CacheLoader; +import com.google.common.cache.LoadingCache; +import com.google.common.cache.Weigher; +import com.google.common.collect.Maps; +import io.netty.buffer.ByteBuf; +import io.netty.buffer.Unpooled; +import org.roaringbitmap.RoaringBitmap; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.spark.network.buffer.FileSegmentManagedBuffer; +import org.apache.spark.network.buffer.ManagedBuffer; +import org.apache.spark.network.client.StreamCallbackWithID; +import org.apache.spark.network.protocol.Encoders; +import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo; +import org.apache.spark.network.shuffle.protocol.FinalizeShuffleMerge; +import org.apache.spark.network.shuffle.protocol.MergeStatuses; +import org.apache.spark.network.shuffle.protocol.PushBlockStream; +import org.apache.spark.network.util.JavaUtils; +import org.apache.spark.network.util.NettyUtils; +import org.apache.spark.network.util.TransportConf; + +/** + * An implementation of {@link MergedShuffleFileManager} that provides the most essential shuffle + * service processing logic to support push based shuffle. + */ +public class RemoteBlockPushResolver implements MergedShuffleFileManager { + + private static final Logger logger = LoggerFactory.getLogger(RemoteBlockPushResolver.class); + @VisibleForTesting + static final String MERGE_MANAGER_DIR = "merge_manager"; + + private final ConcurrentMap<String, AppPathsInfo> appsPathInfo; + private final ConcurrentMap<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> partitions; + + private final Executor directoryCleaner; + private final TransportConf conf; + private final int minChunkSize; + private final ErrorHandler.BlockPushErrorHandler errorHandler; + + @SuppressWarnings("UnstableApiUsage") + private final LoadingCache<File, ShuffleIndexInformation> indexCache; + + @SuppressWarnings("UnstableApiUsage") + public RemoteBlockPushResolver(TransportConf conf) { + this.conf = conf; + this.partitions = Maps.newConcurrentMap(); + this.appsPathInfo = Maps.newConcurrentMap(); + this.directoryCleaner = Executors.newSingleThreadExecutor( + // Add `spark` prefix because it will run in NM in Yarn mode. + NettyUtils.createThreadFactory("spark-shuffle-merged-shuffle-directory-cleaner")); + this.minChunkSize = conf.minChunkSizeInMergedShuffleFile(); + CacheLoader<File, ShuffleIndexInformation> indexCacheLoader = + new CacheLoader<File, ShuffleIndexInformation>() { + public ShuffleIndexInformation load(File file) throws IOException { + return new ShuffleIndexInformation(file); + } + }; + indexCache = CacheBuilder.newBuilder() + .maximumWeight(conf.mergedIndexCacheSize()) + .weigher((Weigher<File, ShuffleIndexInformation>) (file, indexInfo) -> indexInfo.getSize()) + .build(indexCacheLoader); + this.errorHandler = new ErrorHandler.BlockPushErrorHandler(); + } + + /** + * Given the appShuffleId and reduceId that uniquely identifies a given shuffle partition of an + * application, retrieves the associated metadata. If not present and the corresponding merged + * shuffle does not exist, initializes the metadata. + */ + private AppShufflePartitionInfo getOrCreateAppShufflePartitionInfo( + AppShuffleId appShuffleId, + int reduceId) { + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!partitions.containsKey(appShuffleId) && dataFile.exists()) { + // If this partition is already finalized then the partitions map will not contain + // the appShuffleId but the data file would exist. In that case the block is considered late. + return null; + } + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + partitions.computeIfAbsent(appShuffleId, id -> Maps.newConcurrentMap()); + return shufflePartitions.computeIfAbsent(reduceId, key -> { + // It only gets here when the key is not present in the map. This could either + // be the first time the merge manager receives a pushed block for a given application + // shuffle partition, or after the merged shuffle file is finalized. We handle these + // two cases accordingly by checking if the file already exists. + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + try { + if (dataFile.exists()) { + return null; + } else { + return new AppShufflePartitionInfo(appShuffleId, reduceId, dataFile, indexFile, metaFile); + } + } catch (IOException e) { + logger.error( + "Cannot create merged shuffle partition with data file {}, index file {}, and " + + "meta file {}", dataFile.getAbsolutePath(), + indexFile.getAbsolutePath(), metaFile.getAbsolutePath()); + throw new RuntimeException( + String.format("Cannot initialize merged shuffle partition for appId %s shuffleId %s " + + "reduceId %s", appShuffleId.appId, appShuffleId.shuffleId, reduceId), e); + } + }); + } + + @Override + public MergedBlockMeta getMergedBlockMeta(String appId, int shuffleId, int reduceId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + if (!indexFile.exists()) { + throw new RuntimeException(String.format( + "Merged shuffle index file %s not found", indexFile.getPath())); + } + int size = (int) indexFile.length(); + // First entry is the zero offset + int numChunks = (size / Long.BYTES) - 1; + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + if (!metaFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle meta file %s not found", + metaFile.getPath())); + } + FileSegmentManagedBuffer chunkBitMaps = + new FileSegmentManagedBuffer(conf, metaFile, 0L, metaFile.length()); + logger.trace( + "{} shuffleId {} reduceId {} num chunks {}", appId, shuffleId, reduceId, numChunks); + return new MergedBlockMeta(numChunks, chunkBitMaps); + } + + @SuppressWarnings("UnstableApiUsage") + @Override + public ManagedBuffer getMergedBlockData(String appId, int shuffleId, int reduceId, int chunkId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!dataFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle data file %s not found", + dataFile.getPath())); + } + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + try { + // If we get here, the merged shuffle file should have been properly finalized. Thus we can + // use the file length to determine the size of the merged shuffle block. + ShuffleIndexInformation shuffleIndexInformation = indexCache.get(indexFile); + ShuffleIndexRecord shuffleIndexRecord = shuffleIndexInformation.getIndex(chunkId); + return new FileSegmentManagedBuffer( + conf, dataFile, shuffleIndexRecord.getOffset(), shuffleIndexRecord.getLength()); + } catch (ExecutionException e) { + throw new RuntimeException(String.format( + "Failed to open merged shuffle index file %s", indexFile.getPath()), e); + } + } + + /** + * The logic here is consistent with + * org.apache.spark.storage.DiskBlockManager#getMergedShuffleFile + */ + private File getFile(String appId, String filename) { + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + File targetFile = ExecutorDiskUtils.getFile(appPathsInfo.activeLocalDirs, + appPathsInfo.subDirsPerLocalDir, filename); + logger.debug("Get merged file {}", targetFile.getAbsolutePath()); + return targetFile; + } + + private File getMergedShuffleDataFile(AppShuffleId appShuffleId, int reduceId) { + String fileName = String.format("%s.data", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, fileName); + } + + private File getMergedShuffleIndexFile(AppShuffleId appShuffleId, int reduceId) { + String indexName = String.format("%s.index", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, indexName); + } + + private File getMergedShuffleMetaFile(AppShuffleId appShuffleId, int reduceId) { + String metaName = String.format("%s.meta", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, metaName); + } + + @Override + public String[] getMergedBlockDirs(String appId) { + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + String[] activeLocalDirs = Preconditions.checkNotNull(appPathsInfo.activeLocalDirs, + "application " + appId + + " active local dirs list has not been updated by any executor registration"); + return activeLocalDirs; + } + + @Override + public void applicationRemoved(String appId, boolean cleanupLocalDirs) { + logger.info("Application {} removed, cleanupLocalDirs = {}", appId, cleanupLocalDirs); + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.remove(appId), + "application " + appId + " is not registered or NM was restarted."); + Iterator<Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>>> iterator = + partitions.entrySet().iterator(); + while (iterator.hasNext()) { + Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> entry = iterator.next(); + AppShuffleId appShuffleId = entry.getKey(); + if (appId.equals(appShuffleId.appId)) { + iterator.remove(); + for (AppShufflePartitionInfo partitionInfo : entry.getValue().values()) { + partitionInfo.closeAllFiles(); + } + } + } + if (cleanupLocalDirs) { + Path[] dirs = Arrays.stream(appPathsInfo.activeLocalDirs) + .map(dir -> Paths.get(dir)).toArray(Path[]::new); + directoryCleaner.execute(() -> deleteExecutorDirs(dirs)); + } + } + + /** + * Serially delete local dirs, executed in a separate thread. + */ + @VisibleForTesting + void deleteExecutorDirs(Path[] dirs) { + for (Path localDir : dirs) { + try { + if (Files.exists(localDir)) { + JavaUtils.deleteRecursively(localDir.toFile()); + logger.debug("Successfully cleaned up directory: {}", localDir); + } + } catch (Exception e) { + logger.error("Failed to delete directory: {}", localDir, e); + } + } + } + + @Override + public StreamCallbackWithID receiveBlockDataAsStream(PushBlockStream msg) { + // Retrieve merged shuffle file metadata + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + AppShufflePartitionInfo partitionInfoBeforeCheck = + getOrCreateAppShufflePartitionInfo(appShuffleId, msg.reduceId); + // Here partitionInfo will be null in 2 cases: + // 1) The request is received for a block that has already been merged, this is possible due + // to the retry logic. + // 2) The request is received after the merged shuffle is finalized, thus is too late. + // + // For case 1, we will drain the data in the channel and just respond success + // to the client. This is required because the response of the previously merged + // block will be ignored by the client, per the logic in RetryingBlockFetcher. + // Note that the netty server should receive data for a given block id only from 1 channel + // at any time. The block should be pushed only from successful maps, thus there should be + // only 1 source for a given block at any time. Although the netty client might retry sending + // this block to the server multiple times, the data of the same block always arrives from the + // same channel thus the server should have already processed the previous request of this + // block before seeing it again in the channel. This guarantees that we can simply just + // check the bitmap to determine if a block is a duplicate or not. + // + // For case 2, we will also drain the data in the channel, but throw an exception in + // {@link org.apache.spark.network.client.StreamCallback#onComplete(String)}. This way, + // the client will be notified of the failure but the channel will remain active. Keeping + // the channel alive is important because the same channel could be reused by multiple map + // tasks in the executor JVM, which belongs to different stages. While one of the shuffles + // in these stages is finalized, the others might still be active. Tearing down the channel + // on the server side will disrupt these other on-going shuffle merges. It's also important + // to notify the client of the failure, so that it can properly halt pushing the remaining + // blocks upon receiving such failures to preserve resources on the server/client side. + // + // Speculative execution would also raise a possible scenario with duplicate blocks. Although + // speculative execution would kill the slower task attempt, leading to only 1 task attempt + // succeeding in the end, there is no guarantee that only one copy of the block will be + // pushed. This is due to our handling of block push process outside of the map task, thus + // it is possible for the speculative task attempt to initiate the block push process before + // getting killed. When this happens, we need to distinguish the duplicate blocks as they + // arrive. More details on this is explained in later comments. + + // Track if the block is received after shuffle merge finalize + final boolean isTooLate = partitionInfoBeforeCheck == null; + // Check if the given block is already merged by checking the bitmap against the given map index + final AppShufflePartitionInfo partitionInfo = partitionInfoBeforeCheck != null + && partitionInfoBeforeCheck.mapTracker.contains(msg.mapIndex) ? null + : partitionInfoBeforeCheck; + if (partitionInfo != null) { + return new PushBlockStreamCallback( + this, msg, appShuffleId, msg.reduceId, msg.mapIndex, partitionInfo); + } else { + // For a duplicate block or a block which is late, respond back with a callback that handles + // them differently. + return new StreamCallbackWithID() { + @Override + public String getID() { + return msg.streamId; + } + + @Override + public void onData(String streamId, ByteBuffer buf) { + // Ignore the requests. It reaches here either when a request is received after the + // shuffle file is finalized or when a request is for a duplicate block. + } + + @Override + public void onComplete(String streamId) { + if (isTooLate) { + // Throw an exception here so the block data is drained from channel and server + // responds RpcFailure to the client. + throw new RuntimeException(String.format("Block %s %s", msg.streamId, + ErrorHandler.BlockPushErrorHandler.TOO_LATE_MESSAGE_SUFFIX)); + } + // For duplicate block that is received before the shuffle merge finalizes, the + // server should respond success to the client. + } + + @Override + public void onFailure(String streamId, Throwable cause) { + } + }; + } + } + + @SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter") + @Override + public MergeStatuses finalizeShuffleMerge(FinalizeShuffleMerge msg) throws IOException { + logger.info("Finalizing shuffle {} from Application {}.", msg.shuffleId, msg.appId); + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + Map<Integer, AppShufflePartitionInfo> shufflePartitions = partitions.get(appShuffleId); + MergeStatuses mergeStatuses; + if (shufflePartitions == null || shufflePartitions.isEmpty()) { + mergeStatuses = + new MergeStatuses(msg.shuffleId, new RoaringBitmap[0], new int[0], new long[0]); + } else { + Collection<AppShufflePartitionInfo> partitionsToFinalize = shufflePartitions.values(); + int totalPartitions = partitionsToFinalize.size(); + RoaringBitmap[] bitmaps = new RoaringBitmap[totalPartitions]; + int[] reduceIds = new int[totalPartitions]; + long[] sizes = new long[totalPartitions]; + Iterator<AppShufflePartitionInfo> partitionsIter = partitionsToFinalize.iterator(); + int idx = 0; + while (partitionsIter.hasNext()) { + AppShufflePartitionInfo partition = partitionsIter.next(); + synchronized (partition) { + // Get rid of any partial block data at the end of the file. This could either + // be due to failure or a request still being processed when the shuffle + // merge gets finalized. + try { + partition.dataChannel.truncate(partition.getPosition()); + if (partition.getPosition() != partition.getLastChunkOffset()) { + partition.updateChunkInfo(partition.getPosition(), partition.lastMergedMapIndex); + } + bitmaps[idx] = partition.mapTracker; + reduceIds[idx] = partition.reduceId; + sizes[idx++] = partition.getPosition(); + } catch (IOException ioe) { + logger.warn("Exception while finalizing shuffle partition {} {} {}", msg.appId, + msg.shuffleId, partition.reduceId, ioe); + } finally { + partition.closeAllFiles(); + // The partition should be removed after the files are written so that any new stream + // for the same reduce partition will see that the data file exists. + partitionsIter.remove(); + } + } + } + mergeStatuses = new MergeStatuses(msg.shuffleId, bitmaps, reduceIds, sizes); + } + partitions.remove(appShuffleId); + logger.info("Finalized shuffle {} from Application {}.", msg.shuffleId, msg.appId); + return mergeStatuses; + } + + @Override + public void registerExecutor(String appId, ExecutorShuffleInfo executorInfo) { + if (logger.isDebugEnabled()) { + logger.debug("register executor with RemoteBlockPushResolver {} local-dirs {} " + + "num sub-dirs {}", appId, Arrays.toString(executorInfo.localDirs), + executorInfo.subDirsPerLocalDir); + } + appsPathInfo.putIfAbsent(appId, new AppPathsInfo()); + appsPathInfo.compute(appId, (targetAppId, appPathsInfo) -> { + assert appPathsInfo != null; + return appPathsInfo.updateActiveLocalDirs(targetAppId, executorInfo.localDirs, + executorInfo.subDirsPerLocalDir); + }); + } + + private static String generateFileName(AppShuffleId appShuffleId, int reduceId) { + return String.format("mergedShuffle_%s_%d_%d", appShuffleId.appId, appShuffleId.shuffleId, + reduceId); + } + + /** + * Callback for push stream that handles blocks which are not already merged. + */ + static class PushBlockStreamCallback implements StreamCallbackWithID { + + private final RemoteBlockPushResolver mergeManager; + private final PushBlockStream msg; + private final AppShuffleId appShuffleId; + private final int reduceId; + private final int mapIndex; + private final AppShufflePartitionInfo partitionInfo; + private int length = 0; + // This indicates that this stream got the opportunity to write the blocks to the merged file. + // Once this is set to true and the stream encounters a failure then it will take necessary + // action to overwrite any partial written data. This is reset to false when the stream + // completes without any failures. + private boolean isWriting = false; + // Use on-heap instead of direct ByteBuffer since these buffers will be GC'ed very quickly + private List<ByteBuffer> deferredBufs; + + private PushBlockStreamCallback( + RemoteBlockPushResolver mergeManager, + PushBlockStream msg, + AppShuffleId appShuffleId, + int reduceId, + int mapIndex, + AppShufflePartitionInfo partitionInfo) { + this.mergeManager = Preconditions.checkNotNull(mergeManager); + this.msg = Preconditions.checkNotNull(msg); + this.appShuffleId = appShuffleId; + this.reduceId = reduceId; + this.mapIndex = mapIndex; + this.partitionInfo = Preconditions.checkNotNull(partitionInfo); + } + + @Override + public String getID() { + return msg.streamId; + } + + /** + * Write a ByteBuffer to the merged shuffle file. Here we keep track of the length of the + * block data written to file. In case of failure during writing block to file, we use the + * information tracked in partitionInfo to overwrite the corrupt block when writing the new + * block. + */ + private void writeBuf(ByteBuffer buf) throws IOException { + while (buf.hasRemaining()) { + if (partitionInfo.isEncounteredFailure()) { + long updatedPos = partitionInfo.getPosition() + length; + logger.debug( + "{} shuffleId {} reduceId {} encountered failure current pos {} updated pos {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, partitionInfo.getPosition(), + updatedPos); + length += partitionInfo.dataChannel.write(buf, updatedPos); + } else { + length += partitionInfo.dataChannel.write(buf); + } + } + } + + /** + * There will be multiple streams of map blocks belonging to the same reduce partition. At any + * given point of time, only a single map stream can write its data to the merged file. Until + * this stream is completed, the other streams defer writing. This prevents corruption of + * merged data. This returns whether this stream is the active stream that can write to the + * merged file. + */ + private boolean allowedToWrite() { + return partitionInfo.getCurrentMapIndex() < 0 + || partitionInfo.getCurrentMapIndex() == mapIndex; + } + + /** + * Returns if this is a duplicate block generated by speculative tasks. With speculative + * tasks, we could receive the same block from 2 different sources at the same time. One of + * them is going to be the first to set the currentMapIndex. When that block does so, it's + * going to see the currentMapIndex initially as -1. After it sets the currentMapIndex, it's + * going to write some data to disk, thus increasing the length counter. The other duplicate + * block is going to see the currentMapIndex already set to its mapIndex. However, it hasn't + * written any data yet. If the first block gets written completely and resets the + * currentMapIndex to -1 before the processing for the second block finishes, we can just + * check the bitmap to identify the second as a duplicate. + */ + private boolean isDuplicateBlock() { + return (partitionInfo.getCurrentMapIndex() == mapIndex && length == 0) + || partitionInfo.mapTracker.contains(mapIndex); + } + + /** + * This is only invoked when the stream is able to write. The stream first writes any deferred + * block parts buffered in memory. + */ + private void writeAnyDeferredBufs() throws IOException { + if (deferredBufs != null && !deferredBufs.isEmpty()) { + for (ByteBuffer deferredBuf : deferredBufs) { + writeBuf(deferredBuf); + } + deferredBufs = null; + } + } + + @Override + public void onData(String streamId, ByteBuffer buf) throws IOException { + // When handling the block data using StreamInterceptor, it can help to reduce the amount + // of data that needs to be buffered in memory since it does not wait till the completion + // of the frame before handling the message, thus releasing the ByteBuf earlier. However, + // this also means it would chunk a block into multiple buffers. Here, we want to preserve + // the benefit of handling the block data using StreamInterceptor as much as possible while + // providing the guarantee that one block would be continuously written to the merged + // shuffle file before the next block starts. For each shuffle partition, we would track + // the current map index to make sure only block matching the map index can be written to + // disk. If one server thread sees the block being handled is the current block, it would + // directly write the block to disk. Otherwise, it would buffer the block chunks in memory. + // If the block becomes the current block before we see the end of it, we would then dump + // all buffered block data to disk and write the remaining portions of the block directly + // to disk as well. This way, we avoid having to buffer the entirety of every blocks in + // memory, while still providing the necessary guarantee. + synchronized (partitionInfo) { + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + mergeManager.partitions.get(appShuffleId); + // If the partitionInfo corresponding to (appId, shuffleId, reduceId) is no longer present + // then it means that the shuffle merge has already been finalized. We should thus ignore + // the data and just drain the remaining bytes of this message. This check should be + // placed inside the synchronized block to make sure that checking the key is still + // present and processing the data is atomic. + if (shufflePartitions == null || !shufflePartitions.containsKey(reduceId)) { + // TODO is it necessary to dereference deferredBufs? + deferredBufs = null; + return; + } + // Check whether we can write to disk + if (allowedToWrite()) { + isWriting = true; + // Identify duplicate block generated by speculative tasks. We respond success to + // the client in cases of duplicate even though no data is written. + if (isDuplicateBlock()) { + deferredBufs = null; + return; + } + logger.trace("{} shuffleId {} reduceId {} onData writable", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + if (partitionInfo.getCurrentMapIndex() < 0) { + partitionInfo.setCurrentMapIndex(mapIndex); + } + + // If we got here, it's safe to write the block data to the merged shuffle file. We + // first write any deferred block. + writeAnyDeferredBufs(); + writeBuf(buf); + // If we got here, it means we successfully write the current chunk of block to merged + // shuffle file. If we encountered failure while writing the previous block, we should + // reset the file channel position and the status of partitionInfo to indicate that we + // have recovered from previous disk write failure. However, we do not update the + // position tracked by partitionInfo here. That is only updated while the entire block + // is successfully written to merged shuffle file. + if (partitionInfo.isEncounteredFailure()) { + partitionInfo.dataChannel.position(partitionInfo.getPosition() + length); + partitionInfo.setEncounteredFailure(false); + } + } else { + logger.trace("{} shuffleId {} reduceId {} onData deferred", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + // If we cannot write to disk, we buffer the current block chunk in memory so it could + // potentially be written to disk later. We take our best effort without guarantee + // that the block will be written to disk. If the block data is divided into multiple + // chunks during TCP transportation, each #onData invocation is an attempt to write + // the block to disk. If the block is still not written to disk after all #onData + // invocations, the final #onComplete invocation is the last attempt to write the + // block to disk. If we still couldn't write this block to disk after this, we give up + // on this block push request and respond failure to client. We could potentially + // buffer the block longer or wait for a few iterations inside #onData or #onComplete + // to increase the chance of writing the block to disk, however this would incur more + // memory footprint or decrease the server processing throughput for the shuffle + // service. In addition, during test we observed that by randomizing the order in + // which clients sends block push requests batches, only ~0.5% blocks failed to be + // written to disk due to this reason. We thus decide to optimize for server + // throughput and memory usage. + if (deferredBufs == null) { + deferredBufs = new LinkedList<>(); + } + // Write the buffer to the in-memory deferred cache. Since buf is a slice of a larger + // byte buffer, we cache only the relevant bytes not the entire large buffer to save + // memory. + ByteBuffer deferredBuf = ByteBuffer.allocate(buf.remaining()); + deferredBuf.put(buf); + deferredBuf.flip(); + deferredBufs.add(deferredBuf); + } + } + } + + @Override + public void onComplete(String streamId) throws IOException { + // TODO should the merge manager check for the merge completion ratio here and finalize + // TODO shuffle merge if appropriate? So the merge manager can potentially finalize early + // TODO and the file channel can be closed even if finalize merge request is somehow not + // TODO received from the driver? If so, then we need to know # maps for this shuffle. + + synchronized (partitionInfo) { + logger.trace("{} shuffleId {} reduceId {} onComplete invoked", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + mergeManager.partitions.get(appShuffleId); + // When this request initially got to the server, the shuffle merge finalize request + // was not received yet. By the time we finish reading this message, the shuffle merge + // however is already finalized. We should thus respond RpcFailure to the client. + if (shufflePartitions == null || !shufflePartitions.containsKey(reduceId)) { + deferredBufs = null; + throw new RuntimeException(String.format("Block %s %s", msg.streamId, + ErrorHandler.BlockPushErrorHandler.TOO_LATE_MESSAGE_SUFFIX)); + } + // Check if we can commit this block + if (allowedToWrite()) { + isWriting = true; + // Identify duplicate block generated by speculative tasks. We respond success to + // the client in cases of duplicate even though no data is written. + if (isDuplicateBlock()) { + deferredBufs = null; + return; + } + if (partitionInfo.getCurrentMapIndex() < 0) { + writeAnyDeferredBufs(); + } + long updatedPos = partitionInfo.getPosition() + length; + boolean indexUpdated = false; + if (updatedPos - partitionInfo.getLastChunkOffset() >= mergeManager.minChunkSize) { + partitionInfo.updateChunkInfo(updatedPos, mapIndex); + indexUpdated = true; + } + partitionInfo.setPosition(updatedPos); + partitionInfo.setCurrentMapIndex(-1); + + // update merged results + partitionInfo.blockMerged(mapIndex); + if (indexUpdated) { + partitionInfo.resetChunkTracker(); + } + } else { + deferredBufs = null; Review comment: Could we log a warning too in addition to the exception? ########## File path: common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RemoteBlockPushResolver.java ########## @@ -0,0 +1,966 @@ +/* + * 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.network.shuffle; + +import java.io.BufferedOutputStream; +import java.io.DataOutputStream; +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.channels.FileChannel; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.Arrays; +import java.util.Collection; +import java.util.Iterator; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Executor; +import java.util.concurrent.Executors; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Objects; +import com.google.common.base.Preconditions; +import com.google.common.cache.CacheBuilder; +import com.google.common.cache.CacheLoader; +import com.google.common.cache.LoadingCache; +import com.google.common.cache.Weigher; +import com.google.common.collect.Maps; +import io.netty.buffer.ByteBuf; +import io.netty.buffer.Unpooled; +import org.roaringbitmap.RoaringBitmap; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.spark.network.buffer.FileSegmentManagedBuffer; +import org.apache.spark.network.buffer.ManagedBuffer; +import org.apache.spark.network.client.StreamCallbackWithID; +import org.apache.spark.network.protocol.Encoders; +import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo; +import org.apache.spark.network.shuffle.protocol.FinalizeShuffleMerge; +import org.apache.spark.network.shuffle.protocol.MergeStatuses; +import org.apache.spark.network.shuffle.protocol.PushBlockStream; +import org.apache.spark.network.util.JavaUtils; +import org.apache.spark.network.util.NettyUtils; +import org.apache.spark.network.util.TransportConf; + +/** + * An implementation of {@link MergedShuffleFileManager} that provides the most essential shuffle + * service processing logic to support push based shuffle. + */ +public class RemoteBlockPushResolver implements MergedShuffleFileManager { + + private static final Logger logger = LoggerFactory.getLogger(RemoteBlockPushResolver.class); + @VisibleForTesting + static final String MERGE_MANAGER_DIR = "merge_manager"; + + private final ConcurrentMap<String, AppPathsInfo> appsPathInfo; + private final ConcurrentMap<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> partitions; + + private final Executor directoryCleaner; + private final TransportConf conf; + private final int minChunkSize; + private final ErrorHandler.BlockPushErrorHandler errorHandler; + + @SuppressWarnings("UnstableApiUsage") + private final LoadingCache<File, ShuffleIndexInformation> indexCache; + + @SuppressWarnings("UnstableApiUsage") + public RemoteBlockPushResolver(TransportConf conf) { + this.conf = conf; + this.partitions = Maps.newConcurrentMap(); + this.appsPathInfo = Maps.newConcurrentMap(); + this.directoryCleaner = Executors.newSingleThreadExecutor( + // Add `spark` prefix because it will run in NM in Yarn mode. + NettyUtils.createThreadFactory("spark-shuffle-merged-shuffle-directory-cleaner")); + this.minChunkSize = conf.minChunkSizeInMergedShuffleFile(); + CacheLoader<File, ShuffleIndexInformation> indexCacheLoader = + new CacheLoader<File, ShuffleIndexInformation>() { + public ShuffleIndexInformation load(File file) throws IOException { + return new ShuffleIndexInformation(file); + } + }; + indexCache = CacheBuilder.newBuilder() + .maximumWeight(conf.mergedIndexCacheSize()) + .weigher((Weigher<File, ShuffleIndexInformation>) (file, indexInfo) -> indexInfo.getSize()) + .build(indexCacheLoader); + this.errorHandler = new ErrorHandler.BlockPushErrorHandler(); + } + + /** + * Given the appShuffleId and reduceId that uniquely identifies a given shuffle partition of an + * application, retrieves the associated metadata. If not present and the corresponding merged + * shuffle does not exist, initializes the metadata. + */ + private AppShufflePartitionInfo getOrCreateAppShufflePartitionInfo( + AppShuffleId appShuffleId, + int reduceId) { + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!partitions.containsKey(appShuffleId) && dataFile.exists()) { + // If this partition is already finalized then the partitions map will not contain + // the appShuffleId but the data file would exist. In that case the block is considered late. + return null; + } + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + partitions.computeIfAbsent(appShuffleId, id -> Maps.newConcurrentMap()); + return shufflePartitions.computeIfAbsent(reduceId, key -> { + // It only gets here when the key is not present in the map. This could either + // be the first time the merge manager receives a pushed block for a given application + // shuffle partition, or after the merged shuffle file is finalized. We handle these + // two cases accordingly by checking if the file already exists. + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + try { + if (dataFile.exists()) { + return null; + } else { + return new AppShufflePartitionInfo(appShuffleId, reduceId, dataFile, indexFile, metaFile); + } + } catch (IOException e) { + logger.error( + "Cannot create merged shuffle partition with data file {}, index file {}, and " + + "meta file {}", dataFile.getAbsolutePath(), + indexFile.getAbsolutePath(), metaFile.getAbsolutePath()); + throw new RuntimeException( + String.format("Cannot initialize merged shuffle partition for appId %s shuffleId %s " + + "reduceId %s", appShuffleId.appId, appShuffleId.shuffleId, reduceId), e); + } + }); + } + + @Override + public MergedBlockMeta getMergedBlockMeta(String appId, int shuffleId, int reduceId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + if (!indexFile.exists()) { + throw new RuntimeException(String.format( + "Merged shuffle index file %s not found", indexFile.getPath())); + } + int size = (int) indexFile.length(); + // First entry is the zero offset + int numChunks = (size / Long.BYTES) - 1; + File metaFile = getMergedShuffleMetaFile(appShuffleId, reduceId); + if (!metaFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle meta file %s not found", + metaFile.getPath())); + } + FileSegmentManagedBuffer chunkBitMaps = + new FileSegmentManagedBuffer(conf, metaFile, 0L, metaFile.length()); + logger.trace( + "{} shuffleId {} reduceId {} num chunks {}", appId, shuffleId, reduceId, numChunks); + return new MergedBlockMeta(numChunks, chunkBitMaps); + } + + @SuppressWarnings("UnstableApiUsage") + @Override + public ManagedBuffer getMergedBlockData(String appId, int shuffleId, int reduceId, int chunkId) { + AppShuffleId appShuffleId = new AppShuffleId(appId, shuffleId); + File dataFile = getMergedShuffleDataFile(appShuffleId, reduceId); + if (!dataFile.exists()) { + throw new RuntimeException(String.format("Merged shuffle data file %s not found", + dataFile.getPath())); + } + File indexFile = getMergedShuffleIndexFile(appShuffleId, reduceId); + try { + // If we get here, the merged shuffle file should have been properly finalized. Thus we can + // use the file length to determine the size of the merged shuffle block. + ShuffleIndexInformation shuffleIndexInformation = indexCache.get(indexFile); + ShuffleIndexRecord shuffleIndexRecord = shuffleIndexInformation.getIndex(chunkId); + return new FileSegmentManagedBuffer( + conf, dataFile, shuffleIndexRecord.getOffset(), shuffleIndexRecord.getLength()); + } catch (ExecutionException e) { + throw new RuntimeException(String.format( + "Failed to open merged shuffle index file %s", indexFile.getPath()), e); + } + } + + /** + * The logic here is consistent with + * org.apache.spark.storage.DiskBlockManager#getMergedShuffleFile + */ + private File getFile(String appId, String filename) { + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + File targetFile = ExecutorDiskUtils.getFile(appPathsInfo.activeLocalDirs, + appPathsInfo.subDirsPerLocalDir, filename); + logger.debug("Get merged file {}", targetFile.getAbsolutePath()); + return targetFile; + } + + private File getMergedShuffleDataFile(AppShuffleId appShuffleId, int reduceId) { + String fileName = String.format("%s.data", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, fileName); + } + + private File getMergedShuffleIndexFile(AppShuffleId appShuffleId, int reduceId) { + String indexName = String.format("%s.index", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, indexName); + } + + private File getMergedShuffleMetaFile(AppShuffleId appShuffleId, int reduceId) { + String metaName = String.format("%s.meta", generateFileName(appShuffleId, reduceId)); + return getFile(appShuffleId.appId, metaName); + } + + @Override + public String[] getMergedBlockDirs(String appId) { + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.get(appId), + "application " + appId + " is not registered or NM was restarted."); + String[] activeLocalDirs = Preconditions.checkNotNull(appPathsInfo.activeLocalDirs, + "application " + appId + + " active local dirs list has not been updated by any executor registration"); + return activeLocalDirs; + } + + @Override + public void applicationRemoved(String appId, boolean cleanupLocalDirs) { + logger.info("Application {} removed, cleanupLocalDirs = {}", appId, cleanupLocalDirs); + // TODO: Change the message when this service is able to handle NM restart + AppPathsInfo appPathsInfo = Preconditions.checkNotNull(appsPathInfo.remove(appId), + "application " + appId + " is not registered or NM was restarted."); + Iterator<Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>>> iterator = + partitions.entrySet().iterator(); + while (iterator.hasNext()) { + Map.Entry<AppShuffleId, Map<Integer, AppShufflePartitionInfo>> entry = iterator.next(); + AppShuffleId appShuffleId = entry.getKey(); + if (appId.equals(appShuffleId.appId)) { + iterator.remove(); + for (AppShufflePartitionInfo partitionInfo : entry.getValue().values()) { + partitionInfo.closeAllFiles(); + } + } + } + if (cleanupLocalDirs) { + Path[] dirs = Arrays.stream(appPathsInfo.activeLocalDirs) + .map(dir -> Paths.get(dir)).toArray(Path[]::new); + directoryCleaner.execute(() -> deleteExecutorDirs(dirs)); + } + } + + /** + * Serially delete local dirs, executed in a separate thread. + */ + @VisibleForTesting + void deleteExecutorDirs(Path[] dirs) { + for (Path localDir : dirs) { + try { + if (Files.exists(localDir)) { + JavaUtils.deleteRecursively(localDir.toFile()); + logger.debug("Successfully cleaned up directory: {}", localDir); + } + } catch (Exception e) { + logger.error("Failed to delete directory: {}", localDir, e); + } + } + } + + @Override + public StreamCallbackWithID receiveBlockDataAsStream(PushBlockStream msg) { + // Retrieve merged shuffle file metadata + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + AppShufflePartitionInfo partitionInfoBeforeCheck = + getOrCreateAppShufflePartitionInfo(appShuffleId, msg.reduceId); + // Here partitionInfo will be null in 2 cases: + // 1) The request is received for a block that has already been merged, this is possible due + // to the retry logic. + // 2) The request is received after the merged shuffle is finalized, thus is too late. + // + // For case 1, we will drain the data in the channel and just respond success + // to the client. This is required because the response of the previously merged + // block will be ignored by the client, per the logic in RetryingBlockFetcher. + // Note that the netty server should receive data for a given block id only from 1 channel + // at any time. The block should be pushed only from successful maps, thus there should be + // only 1 source for a given block at any time. Although the netty client might retry sending + // this block to the server multiple times, the data of the same block always arrives from the + // same channel thus the server should have already processed the previous request of this + // block before seeing it again in the channel. This guarantees that we can simply just + // check the bitmap to determine if a block is a duplicate or not. + // + // For case 2, we will also drain the data in the channel, but throw an exception in + // {@link org.apache.spark.network.client.StreamCallback#onComplete(String)}. This way, + // the client will be notified of the failure but the channel will remain active. Keeping + // the channel alive is important because the same channel could be reused by multiple map + // tasks in the executor JVM, which belongs to different stages. While one of the shuffles + // in these stages is finalized, the others might still be active. Tearing down the channel + // on the server side will disrupt these other on-going shuffle merges. It's also important + // to notify the client of the failure, so that it can properly halt pushing the remaining + // blocks upon receiving such failures to preserve resources on the server/client side. + // + // Speculative execution would also raise a possible scenario with duplicate blocks. Although + // speculative execution would kill the slower task attempt, leading to only 1 task attempt + // succeeding in the end, there is no guarantee that only one copy of the block will be + // pushed. This is due to our handling of block push process outside of the map task, thus + // it is possible for the speculative task attempt to initiate the block push process before + // getting killed. When this happens, we need to distinguish the duplicate blocks as they + // arrive. More details on this is explained in later comments. + + // Track if the block is received after shuffle merge finalize + final boolean isTooLate = partitionInfoBeforeCheck == null; + // Check if the given block is already merged by checking the bitmap against the given map index + final AppShufflePartitionInfo partitionInfo = partitionInfoBeforeCheck != null + && partitionInfoBeforeCheck.mapTracker.contains(msg.mapIndex) ? null + : partitionInfoBeforeCheck; + if (partitionInfo != null) { + return new PushBlockStreamCallback( + this, msg, appShuffleId, msg.reduceId, msg.mapIndex, partitionInfo); + } else { + // For a duplicate block or a block which is late, respond back with a callback that handles + // them differently. + return new StreamCallbackWithID() { + @Override + public String getID() { + return msg.streamId; + } + + @Override + public void onData(String streamId, ByteBuffer buf) { + // Ignore the requests. It reaches here either when a request is received after the + // shuffle file is finalized or when a request is for a duplicate block. + } + + @Override + public void onComplete(String streamId) { + if (isTooLate) { + // Throw an exception here so the block data is drained from channel and server + // responds RpcFailure to the client. + throw new RuntimeException(String.format("Block %s %s", msg.streamId, + ErrorHandler.BlockPushErrorHandler.TOO_LATE_MESSAGE_SUFFIX)); + } + // For duplicate block that is received before the shuffle merge finalizes, the + // server should respond success to the client. + } + + @Override + public void onFailure(String streamId, Throwable cause) { + } + }; + } + } + + @SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter") + @Override + public MergeStatuses finalizeShuffleMerge(FinalizeShuffleMerge msg) throws IOException { + logger.info("Finalizing shuffle {} from Application {}.", msg.shuffleId, msg.appId); + AppShuffleId appShuffleId = new AppShuffleId(msg.appId, msg.shuffleId); + Map<Integer, AppShufflePartitionInfo> shufflePartitions = partitions.get(appShuffleId); + MergeStatuses mergeStatuses; + if (shufflePartitions == null || shufflePartitions.isEmpty()) { + mergeStatuses = + new MergeStatuses(msg.shuffleId, new RoaringBitmap[0], new int[0], new long[0]); + } else { + Collection<AppShufflePartitionInfo> partitionsToFinalize = shufflePartitions.values(); + int totalPartitions = partitionsToFinalize.size(); + RoaringBitmap[] bitmaps = new RoaringBitmap[totalPartitions]; + int[] reduceIds = new int[totalPartitions]; + long[] sizes = new long[totalPartitions]; + Iterator<AppShufflePartitionInfo> partitionsIter = partitionsToFinalize.iterator(); + int idx = 0; + while (partitionsIter.hasNext()) { + AppShufflePartitionInfo partition = partitionsIter.next(); + synchronized (partition) { + // Get rid of any partial block data at the end of the file. This could either + // be due to failure or a request still being processed when the shuffle + // merge gets finalized. + try { + partition.dataChannel.truncate(partition.getPosition()); + if (partition.getPosition() != partition.getLastChunkOffset()) { + partition.updateChunkInfo(partition.getPosition(), partition.lastMergedMapIndex); + } + bitmaps[idx] = partition.mapTracker; + reduceIds[idx] = partition.reduceId; + sizes[idx++] = partition.getPosition(); + } catch (IOException ioe) { + logger.warn("Exception while finalizing shuffle partition {} {} {}", msg.appId, + msg.shuffleId, partition.reduceId, ioe); + } finally { + partition.closeAllFiles(); + // The partition should be removed after the files are written so that any new stream + // for the same reduce partition will see that the data file exists. + partitionsIter.remove(); + } + } + } + mergeStatuses = new MergeStatuses(msg.shuffleId, bitmaps, reduceIds, sizes); + } + partitions.remove(appShuffleId); + logger.info("Finalized shuffle {} from Application {}.", msg.shuffleId, msg.appId); + return mergeStatuses; + } + + @Override + public void registerExecutor(String appId, ExecutorShuffleInfo executorInfo) { + if (logger.isDebugEnabled()) { + logger.debug("register executor with RemoteBlockPushResolver {} local-dirs {} " + + "num sub-dirs {}", appId, Arrays.toString(executorInfo.localDirs), + executorInfo.subDirsPerLocalDir); + } + appsPathInfo.putIfAbsent(appId, new AppPathsInfo()); + appsPathInfo.compute(appId, (targetAppId, appPathsInfo) -> { + assert appPathsInfo != null; + return appPathsInfo.updateActiveLocalDirs(targetAppId, executorInfo.localDirs, + executorInfo.subDirsPerLocalDir); + }); + } + + private static String generateFileName(AppShuffleId appShuffleId, int reduceId) { + return String.format("mergedShuffle_%s_%d_%d", appShuffleId.appId, appShuffleId.shuffleId, + reduceId); + } + + /** + * Callback for push stream that handles blocks which are not already merged. + */ + static class PushBlockStreamCallback implements StreamCallbackWithID { + + private final RemoteBlockPushResolver mergeManager; + private final PushBlockStream msg; + private final AppShuffleId appShuffleId; + private final int reduceId; + private final int mapIndex; + private final AppShufflePartitionInfo partitionInfo; + private int length = 0; + // This indicates that this stream got the opportunity to write the blocks to the merged file. + // Once this is set to true and the stream encounters a failure then it will take necessary + // action to overwrite any partial written data. This is reset to false when the stream + // completes without any failures. + private boolean isWriting = false; + // Use on-heap instead of direct ByteBuffer since these buffers will be GC'ed very quickly + private List<ByteBuffer> deferredBufs; + + private PushBlockStreamCallback( + RemoteBlockPushResolver mergeManager, + PushBlockStream msg, + AppShuffleId appShuffleId, + int reduceId, + int mapIndex, + AppShufflePartitionInfo partitionInfo) { + this.mergeManager = Preconditions.checkNotNull(mergeManager); + this.msg = Preconditions.checkNotNull(msg); + this.appShuffleId = appShuffleId; + this.reduceId = reduceId; + this.mapIndex = mapIndex; + this.partitionInfo = Preconditions.checkNotNull(partitionInfo); + } + + @Override + public String getID() { + return msg.streamId; + } + + /** + * Write a ByteBuffer to the merged shuffle file. Here we keep track of the length of the + * block data written to file. In case of failure during writing block to file, we use the + * information tracked in partitionInfo to overwrite the corrupt block when writing the new + * block. + */ + private void writeBuf(ByteBuffer buf) throws IOException { + while (buf.hasRemaining()) { + if (partitionInfo.isEncounteredFailure()) { + long updatedPos = partitionInfo.getPosition() + length; + logger.debug( + "{} shuffleId {} reduceId {} encountered failure current pos {} updated pos {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, partitionInfo.getPosition(), + updatedPos); + length += partitionInfo.dataChannel.write(buf, updatedPos); + } else { + length += partitionInfo.dataChannel.write(buf); + } + } + } + + /** + * There will be multiple streams of map blocks belonging to the same reduce partition. At any + * given point of time, only a single map stream can write its data to the merged file. Until + * this stream is completed, the other streams defer writing. This prevents corruption of + * merged data. This returns whether this stream is the active stream that can write to the + * merged file. + */ + private boolean allowedToWrite() { + return partitionInfo.getCurrentMapIndex() < 0 + || partitionInfo.getCurrentMapIndex() == mapIndex; + } + + /** + * Returns if this is a duplicate block generated by speculative tasks. With speculative + * tasks, we could receive the same block from 2 different sources at the same time. One of + * them is going to be the first to set the currentMapIndex. When that block does so, it's + * going to see the currentMapIndex initially as -1. After it sets the currentMapIndex, it's + * going to write some data to disk, thus increasing the length counter. The other duplicate + * block is going to see the currentMapIndex already set to its mapIndex. However, it hasn't + * written any data yet. If the first block gets written completely and resets the + * currentMapIndex to -1 before the processing for the second block finishes, we can just + * check the bitmap to identify the second as a duplicate. + */ + private boolean isDuplicateBlock() { + return (partitionInfo.getCurrentMapIndex() == mapIndex && length == 0) + || partitionInfo.mapTracker.contains(mapIndex); + } + + /** + * This is only invoked when the stream is able to write. The stream first writes any deferred + * block parts buffered in memory. + */ + private void writeAnyDeferredBufs() throws IOException { + if (deferredBufs != null && !deferredBufs.isEmpty()) { + for (ByteBuffer deferredBuf : deferredBufs) { + writeBuf(deferredBuf); + } + deferredBufs = null; + } + } + + @Override + public void onData(String streamId, ByteBuffer buf) throws IOException { + // When handling the block data using StreamInterceptor, it can help to reduce the amount + // of data that needs to be buffered in memory since it does not wait till the completion + // of the frame before handling the message, thus releasing the ByteBuf earlier. However, + // this also means it would chunk a block into multiple buffers. Here, we want to preserve + // the benefit of handling the block data using StreamInterceptor as much as possible while + // providing the guarantee that one block would be continuously written to the merged + // shuffle file before the next block starts. For each shuffle partition, we would track + // the current map index to make sure only block matching the map index can be written to + // disk. If one server thread sees the block being handled is the current block, it would + // directly write the block to disk. Otherwise, it would buffer the block chunks in memory. + // If the block becomes the current block before we see the end of it, we would then dump + // all buffered block data to disk and write the remaining portions of the block directly + // to disk as well. This way, we avoid having to buffer the entirety of every blocks in + // memory, while still providing the necessary guarantee. + synchronized (partitionInfo) { + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + mergeManager.partitions.get(appShuffleId); + // If the partitionInfo corresponding to (appId, shuffleId, reduceId) is no longer present + // then it means that the shuffle merge has already been finalized. We should thus ignore + // the data and just drain the remaining bytes of this message. This check should be + // placed inside the synchronized block to make sure that checking the key is still + // present and processing the data is atomic. + if (shufflePartitions == null || !shufflePartitions.containsKey(reduceId)) { + // TODO is it necessary to dereference deferredBufs? + deferredBufs = null; + return; + } + // Check whether we can write to disk + if (allowedToWrite()) { + isWriting = true; + // Identify duplicate block generated by speculative tasks. We respond success to + // the client in cases of duplicate even though no data is written. + if (isDuplicateBlock()) { + deferredBufs = null; + return; + } + logger.trace("{} shuffleId {} reduceId {} onData writable", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + if (partitionInfo.getCurrentMapIndex() < 0) { + partitionInfo.setCurrentMapIndex(mapIndex); + } + + // If we got here, it's safe to write the block data to the merged shuffle file. We + // first write any deferred block. + writeAnyDeferredBufs(); + writeBuf(buf); + // If we got here, it means we successfully write the current chunk of block to merged + // shuffle file. If we encountered failure while writing the previous block, we should + // reset the file channel position and the status of partitionInfo to indicate that we + // have recovered from previous disk write failure. However, we do not update the + // position tracked by partitionInfo here. That is only updated while the entire block + // is successfully written to merged shuffle file. + if (partitionInfo.isEncounteredFailure()) { + partitionInfo.dataChannel.position(partitionInfo.getPosition() + length); + partitionInfo.setEncounteredFailure(false); + } + } else { + logger.trace("{} shuffleId {} reduceId {} onData deferred", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + // If we cannot write to disk, we buffer the current block chunk in memory so it could + // potentially be written to disk later. We take our best effort without guarantee + // that the block will be written to disk. If the block data is divided into multiple + // chunks during TCP transportation, each #onData invocation is an attempt to write + // the block to disk. If the block is still not written to disk after all #onData + // invocations, the final #onComplete invocation is the last attempt to write the + // block to disk. If we still couldn't write this block to disk after this, we give up + // on this block push request and respond failure to client. We could potentially + // buffer the block longer or wait for a few iterations inside #onData or #onComplete + // to increase the chance of writing the block to disk, however this would incur more + // memory footprint or decrease the server processing throughput for the shuffle + // service. In addition, during test we observed that by randomizing the order in + // which clients sends block push requests batches, only ~0.5% blocks failed to be + // written to disk due to this reason. We thus decide to optimize for server + // throughput and memory usage. + if (deferredBufs == null) { + deferredBufs = new LinkedList<>(); + } + // Write the buffer to the in-memory deferred cache. Since buf is a slice of a larger + // byte buffer, we cache only the relevant bytes not the entire large buffer to save + // memory. + ByteBuffer deferredBuf = ByteBuffer.allocate(buf.remaining()); + deferredBuf.put(buf); + deferredBuf.flip(); + deferredBufs.add(deferredBuf); + } + } + } + + @Override + public void onComplete(String streamId) throws IOException { + // TODO should the merge manager check for the merge completion ratio here and finalize + // TODO shuffle merge if appropriate? So the merge manager can potentially finalize early + // TODO and the file channel can be closed even if finalize merge request is somehow not + // TODO received from the driver? If so, then we need to know # maps for this shuffle. + + synchronized (partitionInfo) { + logger.trace("{} shuffleId {} reduceId {} onComplete invoked", appShuffleId.appId, + appShuffleId.shuffleId, reduceId); + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + mergeManager.partitions.get(appShuffleId); + // When this request initially got to the server, the shuffle merge finalize request + // was not received yet. By the time we finish reading this message, the shuffle merge + // however is already finalized. We should thus respond RpcFailure to the client. + if (shufflePartitions == null || !shufflePartitions.containsKey(reduceId)) { + deferredBufs = null; + throw new RuntimeException(String.format("Block %s %s", msg.streamId, + ErrorHandler.BlockPushErrorHandler.TOO_LATE_MESSAGE_SUFFIX)); + } + // Check if we can commit this block + if (allowedToWrite()) { + isWriting = true; + // Identify duplicate block generated by speculative tasks. We respond success to + // the client in cases of duplicate even though no data is written. + if (isDuplicateBlock()) { + deferredBufs = null; + return; + } + if (partitionInfo.getCurrentMapIndex() < 0) { + writeAnyDeferredBufs(); + } + long updatedPos = partitionInfo.getPosition() + length; + boolean indexUpdated = false; + if (updatedPos - partitionInfo.getLastChunkOffset() >= mergeManager.minChunkSize) { + partitionInfo.updateChunkInfo(updatedPos, mapIndex); + indexUpdated = true; + } + partitionInfo.setPosition(updatedPos); + partitionInfo.setCurrentMapIndex(-1); + + // update merged results + partitionInfo.blockMerged(mapIndex); + if (indexUpdated) { + partitionInfo.resetChunkTracker(); + } + } else { + deferredBufs = null; + throw new RuntimeException(String.format("%s %s to merged shuffle", + ErrorHandler.BlockPushErrorHandler.BLOCK_APPEND_COLLISION_DETECTED_MSG_PREFIX, + msg.streamId)); + } + } + isWriting = false; + } + + @Override + public void onFailure(String streamId, Throwable throwable) throws IOException { + if (mergeManager.errorHandler.shouldLogError(throwable)) { + logger.error("Encountered issue when merging shuffle partition block {}", msg, throwable); + } else { + logger.debug("Encountered issue when merging shuffle partition block {}", msg, throwable); + } + // Only update partitionInfo if the failure corresponds to a valid request. If the + // request is too late, i.e. received after shuffle merge finalize, #onFailure will + // also be triggered, and we can just ignore. Also, if we couldn't find an opportunity + // to write the block data to disk, we should also ignore here. + if (isWriting) { + synchronized (partitionInfo) { + Map<Integer, AppShufflePartitionInfo> shufflePartitions = + mergeManager.partitions.get(appShuffleId); + if (shufflePartitions != null && shufflePartitions.containsKey(reduceId)) { + logger.debug("{} shuffleId {} reduceId {} set encountered failure", + appShuffleId.appId, appShuffleId.shuffleId, reduceId); + partitionInfo.setCurrentMapIndex(-1); + partitionInfo.setEncounteredFailure(true); + } + } + } + } + } + + /** + * ID that uniquely identifies a shuffle for an application. This is used as a key in + * {@link #partitions}. + */ + public static class AppShuffleId { + public final String appId; + public final int shuffleId; + + AppShuffleId(String appId, int shuffleId) { + this.appId = appId; + this.shuffleId = shuffleId; + } + + @Override + public boolean equals(Object o) { + if (this == o) { + return true; + } + if (o == null || getClass() != o.getClass()) { + return false; + } + AppShuffleId that = (AppShuffleId) o; + return shuffleId == that.shuffleId && Objects.equal(appId, that.appId); + } + + @Override + public int hashCode() { + return Objects.hashCode(appId, shuffleId); + } + + @Override + public String toString() { + return Objects.toStringHelper(this) + .add("appId", appId) + .add("shuffleId", shuffleId) + .toString(); + } + } + + /** Metadata tracked for an actively merged shuffle partition */ + public static class AppShufflePartitionInfo { + + private final AppShuffleId appShuffleId; + private final int reduceId; + // The merged shuffle data file channel + public FileChannel dataChannel; + // Location offset of the last successfully merged block for this shuffle partition + private long position; + // Indicating whether failure was encountered when merging the previous block + private boolean encounteredFailure; + // Track the map index whose block is being merged for this shuffle partition + private int currentMapIndex; + // Bitmap tracking which mapper's blocks have been merged for this shuffle partition + private RoaringBitmap mapTracker; + // The index file for a particular merged shuffle contains the chunk offsets. + private FileChannel indexChannel; + private DataOutputStream indexWriteStream; + // The meta file for a particular merged shuffle contains all the map indices that belong to + // every chunk. The entry per chunk is a serialized bitmap. + private FileChannel metaChannel; + // The offset for the last chunk tracked in the index file for this shuffle partition + private long lastChunkOffset; + private int lastMergedMapIndex = -1; + + // Bitmap tracking which mapper's blocks are in the current shuffle chunk + private RoaringBitmap chunkTracker; + ByteBuf trackerBuf = null; + + AppShufflePartitionInfo( + AppShuffleId appShuffleId, + int reduceId, + File dataFile, + File indexFile, + File metaFile) throws IOException { + this.appShuffleId = Preconditions.checkNotNull(appShuffleId, "app shuffle id"); + this.reduceId = reduceId; + this.dataChannel = new FileOutputStream(dataFile).getChannel(); + FileOutputStream fos = new FileOutputStream(indexFile); + indexChannel = fos.getChannel(); + this.indexWriteStream = new DataOutputStream(new BufferedOutputStream(fos)); + metaChannel = new FileOutputStream(metaFile).getChannel(); + this.currentMapIndex = -1; + // Writing 0 offset so that we can reuse ShuffleIndexInformation.getIndex() + updateChunkInfo(0L, -1); + this.position = 0; + this.encounteredFailure = false; + this.mapTracker = new RoaringBitmap(); + this.chunkTracker = new RoaringBitmap(); + } + + public long getPosition() { + return position; + } + + public void setPosition(long position) { + logger.trace("{} shuffleId {} reduceId {} current pos {} update pos {}", appShuffleId.appId, + appShuffleId.shuffleId, reduceId, this.position, position); + this.position = position; + } + + boolean isEncounteredFailure() { + return encounteredFailure; + } + + void setEncounteredFailure(boolean encounteredFailure) { + this.encounteredFailure = encounteredFailure; + } + + int getCurrentMapIndex() { + return currentMapIndex; + } + + void setCurrentMapIndex(int mapIndex) { + logger.trace("{} shuffleId {} reduceId {} updated mapIndex {} current mapIndex {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, currentMapIndex, mapIndex); + this.currentMapIndex = mapIndex; + } + + long getLastChunkOffset() { + return lastChunkOffset; + } + + void blockMerged(int mapIndex) { + logger.debug("{} shuffleId {} reduceId {} updated merging mapIndex {}", appShuffleId.appId, + appShuffleId.shuffleId, reduceId, mapIndex); + mapTracker.add(mapIndex); + chunkTracker.add(mapIndex); + lastMergedMapIndex = mapIndex; + } + + void resetChunkTracker() { + chunkTracker.clear(); + } + + /** + * Appends the chunk offset to the index file and adds the map index to the chunk tracker. + * + * @param chunkOffset the offset of the chunk in the data file. + * @param mapIndex the map index to be added to chunk tracker. + */ + void updateChunkInfo(long chunkOffset, int mapIndex) throws IOException { + long idxStartPos = -1; + try { + // update the chunk tracker to meta file before index file + writeChunkTracker(mapIndex); + idxStartPos = indexChannel.position(); + logger.trace("{} shuffleId {} reduceId {} updated index current {} updated {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, this.lastChunkOffset, + chunkOffset); + indexWriteStream.writeLong(chunkOffset); + } catch (IOException ioe) { + if (idxStartPos != -1) { + // reset the position to avoid corrupting index files during exception. + logger.warn("{} shuffleId {} reduceId {} reset index to position {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, idxStartPos); + indexChannel.position(idxStartPos); + } + throw ioe; + } + this.lastChunkOffset = chunkOffset; + } + + private void writeChunkTracker(int mapIndex) throws IOException { + if (mapIndex == -1) { + return; + } + chunkTracker.add(mapIndex); + if (trackerBuf == null) { + trackerBuf = Unpooled.buffer(Encoders.Bitmaps.encodedLength(chunkTracker)); + } + Encoders.Bitmaps.encode(trackerBuf, chunkTracker); + long metaStartPos = metaChannel.position(); + try { + logger.trace("{} shuffleId {} reduceId {} mapIndex {} write chunk to meta file", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, mapIndex); + metaChannel.write(trackerBuf.nioBuffer()); + } catch (IOException ioe) { + logger.warn("{} shuffleId {} reduceId {} mapIndex {} reset position of meta file to {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId, mapIndex, metaStartPos); + metaChannel.position(metaStartPos); + throw ioe; + } finally { + trackerBuf.clear(); + } + } + + void closeAllFiles() { + try { + if (dataChannel != null) { + dataChannel.close(); + dataChannel = null; + } + } catch (IOException ioe) { + logger.warn("Error closing data channel for {} shuffleId {} reduceId {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId); + } + try { + if (metaChannel != null) { + metaChannel.close(); + metaChannel = null; + } + } catch (IOException ioe) { + logger.warn("Error closing meta channel for {} shuffleId {} reduceId {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId); + } + try { + if (indexWriteStream != null) { + indexWriteStream.close(); + indexWriteStream = null; + } + } catch (IOException ioe) { + logger.warn("Error closing index stream for {} shuffleId {} reduceId {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId); + } + try { + if (indexChannel != null) { + indexChannel.close(); + indexChannel = null; + } + } catch (IOException ioe) { + logger.warn("Error closing index channel for {} shuffleId {} reduceId {}", + appShuffleId.appId, appShuffleId.shuffleId, reduceId); + } + } + + @Override + protected void finalize() throws Throwable { + closeAllFiles(); + } + } + + /** + * Wraps all the information related to the merge directory of an application. + */ + private static class AppPathsInfo { + + private String[] activeLocalDirs; + private int subDirsPerLocalDir; + + private AppPathsInfo updateActiveLocalDirs( + String appId, + String[] localDirs, + int subDirsPerLocalDir) { + if (activeLocalDirs == null) { + activeLocalDirs = Arrays.stream(localDirs) + .map(localDir -> + // Merge directory is created at the same level as block-manager directory. The list of + // local directories that we get from executorShuffleInfo are paths of each + // block-manager directory. To find out the merge directory location, we first find the + // parent dir and then append the "merger_manager" directory to it. + Paths.get(localDir).getParent().resolve(MERGE_MANAGER_DIR).toFile().getPath()) + .toArray(String[]::new); + this.subDirsPerLocalDir = subDirsPerLocalDir; + if (logger.isInfoEnabled()) { + logger.info("Updated the active local dirs {} for application {}", + Arrays.toString(activeLocalDirs), appId); + } Review comment: nit: too many indentations ---------------------------------------------------------------- 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. 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