| /** |
| * 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; |
| |
| import java.io.IOException; |
| import java.util.*; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.BytesWritable; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| import org.apache.hadoop.mapred.*; |
| import org.apache.hadoop.mapred.join.*; |
| import org.apache.hadoop.mapred.lib.IdentityMapper; |
| import org.apache.hadoop.mapred.lib.IdentityReducer; |
| import org.apache.hadoop.util.Tool; |
| import org.apache.hadoop.util.ToolRunner; |
| |
| /** |
| * This is the trivial map/reduce program that does absolutely nothing |
| * other than use the framework to fragment and sort the input values. |
| * |
| * To run: bin/hadoop jar build/hadoop-examples.jar join |
| * [-m <i>maps</i>] [-r <i>reduces</i>] |
| * [-inFormat <i>input format class</i>] |
| * [-outFormat <i>output format class</i>] |
| * [-outKey <i>output key class</i>] |
| * [-outValue <i>output value class</i>] |
| * [-joinOp <inner|outer|override>] |
| * [<i>in-dir</i>]* <i>in-dir</i> <i>out-dir</i> |
| */ |
| public class Join extends Configured implements Tool { |
| |
| static int printUsage() { |
| System.out.println("join [-m <maps>] [-r <reduces>] " + |
| "[-inFormat <input format class>] " + |
| "[-outFormat <output format class>] " + |
| "[-outKey <output key class>] " + |
| "[-outValue <output value class>] " + |
| "[-joinOp <inner|outer|override>] " + |
| "[input]* <input> <output>"); |
| ToolRunner.printGenericCommandUsage(System.out); |
| return -1; |
| } |
| |
| /** |
| * The main driver for sort program. |
| * Invoke this method to submit the map/reduce job. |
| * @throws IOException When there is communication problems with the |
| * job tracker. |
| */ |
| public int run(String[] args) throws Exception { |
| JobConf jobConf = new JobConf(getConf(), Sort.class); |
| jobConf.setJobName("join"); |
| |
| jobConf.setMapperClass(IdentityMapper.class); |
| jobConf.setReducerClass(IdentityReducer.class); |
| |
| JobClient client = new JobClient(jobConf); |
| ClusterStatus cluster = client.getClusterStatus(); |
| int num_maps = cluster.getTaskTrackers() * |
| jobConf.getInt("test.sort.maps_per_host", 10); |
| int num_reduces = (int) (cluster.getMaxReduceTasks() * 0.9); |
| String sort_reduces = jobConf.get("test.sort.reduces_per_host"); |
| if (sort_reduces != null) { |
| num_reduces = cluster.getTaskTrackers() * |
| Integer.parseInt(sort_reduces); |
| } |
| Class<? extends InputFormat> inputFormatClass = |
| SequenceFileInputFormat.class; |
| Class<? extends OutputFormat> outputFormatClass = |
| SequenceFileOutputFormat.class; |
| Class<? extends WritableComparable> outputKeyClass = BytesWritable.class; |
| Class<? extends Writable> outputValueClass = TupleWritable.class; |
| String op = "inner"; |
| List<String> otherArgs = new ArrayList<String>(); |
| for(int i=0; i < args.length; ++i) { |
| try { |
| if ("-m".equals(args[i])) { |
| num_maps = Integer.parseInt(args[++i]); |
| } else if ("-r".equals(args[i])) { |
| num_reduces = Integer.parseInt(args[++i]); |
| } else if ("-inFormat".equals(args[i])) { |
| inputFormatClass = |
| Class.forName(args[++i]).asSubclass(InputFormat.class); |
| } else if ("-outFormat".equals(args[i])) { |
| outputFormatClass = |
| Class.forName(args[++i]).asSubclass(OutputFormat.class); |
| } else if ("-outKey".equals(args[i])) { |
| outputKeyClass = |
| Class.forName(args[++i]).asSubclass(WritableComparable.class); |
| } else if ("-outValue".equals(args[i])) { |
| outputValueClass = |
| Class.forName(args[++i]).asSubclass(Writable.class); |
| } else if ("-joinOp".equals(args[i])) { |
| op = args[++i]; |
| } else { |
| otherArgs.add(args[i]); |
| } |
| } catch (NumberFormatException except) { |
| System.out.println("ERROR: Integer expected instead of " + args[i]); |
| return printUsage(); |
| } catch (ArrayIndexOutOfBoundsException except) { |
| System.out.println("ERROR: Required parameter missing from " + |
| args[i-1]); |
| return printUsage(); // exits |
| } |
| } |
| |
| // Set user-supplied (possibly default) job configs |
| jobConf.setNumMapTasks(num_maps); |
| jobConf.setNumReduceTasks(num_reduces); |
| |
| if (otherArgs.size() < 2) { |
| System.out.println("ERROR: Wrong number of parameters: "); |
| return printUsage(); |
| } |
| |
| FileOutputFormat.setOutputPath(jobConf, |
| new Path(otherArgs.remove(otherArgs.size() - 1))); |
| List<Path> plist = new ArrayList<Path>(otherArgs.size()); |
| for (String s : otherArgs) { |
| plist.add(new Path(s)); |
| } |
| |
| jobConf.setInputFormat(CompositeInputFormat.class); |
| jobConf.set("mapred.join.expr", CompositeInputFormat.compose( |
| op, inputFormatClass, plist.toArray(new Path[0]))); |
| jobConf.setOutputFormat(outputFormatClass); |
| |
| jobConf.setOutputKeyClass(outputKeyClass); |
| jobConf.setOutputValueClass(outputValueClass); |
| |
| Date startTime = new Date(); |
| System.out.println("Job started: " + startTime); |
| JobClient.runJob(jobConf); |
| Date end_time = new Date(); |
| System.out.println("Job ended: " + end_time); |
| System.out.println("The job took " + |
| (end_time.getTime() - startTime.getTime()) /1000 + " seconds."); |
| return 0; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| int res = ToolRunner.run(new Configuration(), new Join(), args); |
| System.exit(res); |
| } |
| |
| } |