| /** |
| * 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.hadoop.mapreduce.task.reduce; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| |
| import org.apache.hadoop.io.IOUtils; |
| |
| import org.apache.hadoop.mapred.JobConf; |
| import org.apache.hadoop.mapred.Reporter; |
| import org.apache.hadoop.mapred.MapOutputFile; |
| |
| import org.apache.hadoop.mapreduce.TaskAttemptID; |
| import org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.CompressAwarePath; |
| |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| class OnDiskMapOutput<K, V> extends MapOutput<K, V> { |
| private static final Log LOG = LogFactory.getLog(OnDiskMapOutput.class); |
| private final FileSystem localFS; |
| private final Path tmpOutputPath; |
| private final Path outputPath; |
| private final MergeManagerImpl<K, V> merger; |
| private final OutputStream disk; |
| private long compressedSize; |
| |
| public OnDiskMapOutput(TaskAttemptID mapId, TaskAttemptID reduceId, |
| MergeManagerImpl<K, V> merger, long size, |
| JobConf conf, |
| MapOutputFile mapOutputFile, |
| int fetcher, boolean primaryMapOutput) |
| throws IOException { |
| super(mapId, size, primaryMapOutput); |
| this.merger = merger; |
| this.localFS = FileSystem.getLocal(conf); |
| outputPath = |
| mapOutputFile.getInputFileForWrite(mapId.getTaskID(),size); |
| tmpOutputPath = outputPath.suffix(String.valueOf(fetcher)); |
| |
| disk = localFS.create(tmpOutputPath); |
| |
| } |
| |
| @Override |
| public void shuffle(MapHost host, InputStream input, |
| long compressedLength, long decompressedLength, |
| ShuffleClientMetrics metrics, |
| Reporter reporter) throws IOException { |
| // Copy data to local-disk |
| long bytesLeft = compressedLength; |
| try { |
| final int BYTES_TO_READ = 64 * 1024; |
| byte[] buf = new byte[BYTES_TO_READ]; |
| while (bytesLeft > 0) { |
| int n = input.read(buf, 0, (int) Math.min(bytesLeft, BYTES_TO_READ)); |
| if (n < 0) { |
| throw new IOException("read past end of stream reading " + |
| getMapId()); |
| } |
| disk.write(buf, 0, n); |
| bytesLeft -= n; |
| metrics.inputBytes(n); |
| reporter.progress(); |
| } |
| |
| LOG.info("Read " + (compressedLength - bytesLeft) + |
| " bytes from map-output for " + getMapId()); |
| |
| disk.close(); |
| } catch (IOException ioe) { |
| // Close the streams |
| IOUtils.cleanup(LOG, input, disk); |
| |
| // Re-throw |
| throw ioe; |
| } |
| |
| // Sanity check |
| if (bytesLeft != 0) { |
| throw new IOException("Incomplete map output received for " + |
| getMapId() + " from " + |
| host.getHostName() + " (" + |
| bytesLeft + " bytes missing of " + |
| compressedLength + ")"); |
| } |
| this.compressedSize = compressedLength; |
| } |
| |
| @Override |
| public void commit() throws IOException { |
| localFS.rename(tmpOutputPath, outputPath); |
| CompressAwarePath compressAwarePath = new CompressAwarePath(outputPath, |
| getSize(), this.compressedSize); |
| merger.closeOnDiskFile(compressAwarePath); |
| } |
| |
| @Override |
| public void abort() { |
| try { |
| localFS.delete(tmpOutputPath, false); |
| } catch (IOException ie) { |
| LOG.info("failure to clean up " + tmpOutputPath, ie); |
| } |
| } |
| |
| @Override |
| public String getDescription() { |
| return "DISK"; |
| } |
| } |