| /** |
| * 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.examples.terasort; |
| |
| import java.io.IOException; |
| import java.io.PrintStream; |
| import java.net.URI; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.filecache.DistributedCache; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.io.SequenceFile; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapred.FileOutputFormat; |
| import org.apache.hadoop.mapred.JobClient; |
| import org.apache.hadoop.mapred.JobConf; |
| import org.apache.hadoop.mapred.Partitioner; |
| import org.apache.hadoop.util.Tool; |
| import org.apache.hadoop.util.ToolRunner; |
| |
| /** |
| * Generates the sampled split points, launches the job, and waits for it to |
| * finish. |
| * <p> |
| * To run the program: |
| * <b>bin/hadoop jar hadoop-examples-*.jar terasort in-dir out-dir</b> |
| */ |
| public class TeraSort extends Configured implements Tool { |
| private static final Log LOG = LogFactory.getLog(TeraSort.class); |
| |
| /** |
| * A partitioner that splits text keys into roughly equal partitions |
| * in a global sorted order. |
| */ |
| static class TotalOrderPartitioner implements Partitioner<Text,Text>{ |
| private TrieNode trie; |
| private Text[] splitPoints; |
| |
| /** |
| * A generic trie node |
| */ |
| static abstract class TrieNode { |
| private int level; |
| TrieNode(int level) { |
| this.level = level; |
| } |
| abstract int findPartition(Text key); |
| abstract void print(PrintStream strm) throws IOException; |
| int getLevel() { |
| return level; |
| } |
| } |
| |
| /** |
| * An inner trie node that contains 256 children based on the next |
| * character. |
| */ |
| static class InnerTrieNode extends TrieNode { |
| private TrieNode[] child = new TrieNode[256]; |
| |
| InnerTrieNode(int level) { |
| super(level); |
| } |
| int findPartition(Text key) { |
| int level = getLevel(); |
| if (key.getLength() <= level) { |
| return child[0].findPartition(key); |
| } |
| return child[key.getBytes()[level]].findPartition(key); |
| } |
| void setChild(int idx, TrieNode child) { |
| this.child[idx] = child; |
| } |
| void print(PrintStream strm) throws IOException { |
| for(int ch=0; ch < 255; ++ch) { |
| for(int i = 0; i < 2*getLevel(); ++i) { |
| strm.print(' '); |
| } |
| strm.print(ch); |
| strm.println(" ->"); |
| if (child[ch] != null) { |
| child[ch].print(strm); |
| } |
| } |
| } |
| } |
| |
| /** |
| * A leaf trie node that does string compares to figure out where the given |
| * key belongs between lower..upper. |
| */ |
| static class LeafTrieNode extends TrieNode { |
| int lower; |
| int upper; |
| Text[] splitPoints; |
| LeafTrieNode(int level, Text[] splitPoints, int lower, int upper) { |
| super(level); |
| this.splitPoints = splitPoints; |
| this.lower = lower; |
| this.upper = upper; |
| } |
| int findPartition(Text key) { |
| for(int i=lower; i<upper; ++i) { |
| if (splitPoints[i].compareTo(key) >= 0) { |
| return i; |
| } |
| } |
| return upper; |
| } |
| void print(PrintStream strm) throws IOException { |
| for(int i = 0; i < 2*getLevel(); ++i) { |
| strm.print(' '); |
| } |
| strm.print(lower); |
| strm.print(", "); |
| strm.println(upper); |
| } |
| } |
| |
| |
| /** |
| * Read the cut points from the given sequence file. |
| * @param fs the file system |
| * @param p the path to read |
| * @param job the job config |
| * @return the strings to split the partitions on |
| * @throws IOException |
| */ |
| private static Text[] readPartitions(FileSystem fs, Path p, |
| JobConf job) throws IOException { |
| SequenceFile.Reader reader = new SequenceFile.Reader(fs, p, job); |
| List<Text> parts = new ArrayList<Text>(); |
| Text key = new Text(); |
| NullWritable value = NullWritable.get(); |
| while (reader.next(key, value)) { |
| parts.add(key); |
| key = new Text(); |
| } |
| reader.close(); |
| return parts.toArray(new Text[parts.size()]); |
| } |
| |
| /** |
| * Given a sorted set of cut points, build a trie that will find the correct |
| * partition quickly. |
| * @param splits the list of cut points |
| * @param lower the lower bound of partitions 0..numPartitions-1 |
| * @param upper the upper bound of partitions 0..numPartitions-1 |
| * @param prefix the prefix that we have already checked against |
| * @param maxDepth the maximum depth we will build a trie for |
| * @return the trie node that will divide the splits correctly |
| */ |
| private static TrieNode buildTrie(Text[] splits, int lower, int upper, |
| Text prefix, int maxDepth) { |
| int depth = prefix.getLength(); |
| if (depth >= maxDepth || lower == upper) { |
| return new LeafTrieNode(depth, splits, lower, upper); |
| } |
| InnerTrieNode result = new InnerTrieNode(depth); |
| Text trial = new Text(prefix); |
| // append an extra byte on to the prefix |
| trial.append(new byte[1], 0, 1); |
| int currentBound = lower; |
| for(int ch = 0; ch < 255; ++ch) { |
| trial.getBytes()[depth] = (byte) (ch + 1); |
| lower = currentBound; |
| while (currentBound < upper) { |
| if (splits[currentBound].compareTo(trial) >= 0) { |
| break; |
| } |
| currentBound += 1; |
| } |
| trial.getBytes()[depth] = (byte) ch; |
| result.child[ch] = buildTrie(splits, lower, currentBound, trial, |
| maxDepth); |
| } |
| // pick up the rest |
| trial.getBytes()[depth] = 127; |
| result.child[255] = buildTrie(splits, currentBound, upper, trial, |
| maxDepth); |
| return result; |
| } |
| |
| public void configure(JobConf job) { |
| try { |
| FileSystem fs = FileSystem.getLocal(job); |
| Path partFile = new Path(TeraInputFormat.PARTITION_FILENAME); |
| splitPoints = readPartitions(fs, partFile, job); |
| trie = buildTrie(splitPoints, 0, splitPoints.length, new Text(), 2); |
| } catch (IOException ie) { |
| throw new IllegalArgumentException("can't read paritions file", ie); |
| } |
| } |
| |
| public TotalOrderPartitioner() { |
| } |
| |
| public int getPartition(Text key, Text value, int numPartitions) { |
| return trie.findPartition(key); |
| } |
| |
| } |
| |
| public int run(String[] args) throws Exception { |
| LOG.info("starting"); |
| JobConf job = (JobConf) getConf(); |
| Path inputDir = new Path(args[0]); |
| inputDir = inputDir.makeQualified(inputDir.getFileSystem(job)); |
| Path partitionFile = new Path(inputDir, TeraInputFormat.PARTITION_FILENAME); |
| URI partitionUri = new URI(partitionFile.toString() + |
| "#" + TeraInputFormat.PARTITION_FILENAME); |
| TeraInputFormat.setInputPaths(job, new Path(args[0])); |
| FileOutputFormat.setOutputPath(job, new Path(args[1])); |
| job.setJobName("TeraSort"); |
| job.setJarByClass(TeraSort.class); |
| job.setOutputKeyClass(Text.class); |
| job.setOutputValueClass(Text.class); |
| job.setInputFormat(TeraInputFormat.class); |
| job.setOutputFormat(TeraOutputFormat.class); |
| job.setPartitionerClass(TotalOrderPartitioner.class); |
| TeraInputFormat.writePartitionFile(job, partitionFile); |
| DistributedCache.addCacheFile(partitionUri, job); |
| DistributedCache.createSymlink(job); |
| job.setInt("dfs.replication", 1); |
| TeraOutputFormat.setFinalSync(job, true); |
| JobClient.runJob(job); |
| LOG.info("done"); |
| return 0; |
| } |
| |
| /** |
| * @param args |
| */ |
| public static void main(String[] args) throws Exception { |
| int res = ToolRunner.run(new JobConf(), new TeraSort(), args); |
| System.exit(res); |
| } |
| |
| } |