edu.umd.cloud9.pagerank.PartitionGraph.java Source code

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Here is the source code for edu.umd.cloud9.pagerank.PartitionGraph.java

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/*
 * Cloud9: A MapReduce Library for Hadoop
 *
 * Licensed 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 edu.umd.cloud9.pagerank;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

/**
 * <p>
 * Driver program for partitioning the graph. Command-line arguments are as
 * follows:
 * </p>
 * 
 * <ul>
 * 
 * <li>[inputDir]: input directory</li>
 * <li>[outputDir]: output directory</li>
 * <li>[numPartitions]: number of partitions</li>
 * <li>[useRange?]: 1 to user range partitioning or 0 otherwise</li>
 * <li>[nodeCount]: number of nodes in the graph</li>
 * 
 * </ul>
 * 
 * @author Jimmy Lin
 * @author Michael Schatz
 * 
 */
public class PartitionGraph extends Configured implements Tool {
    private static final Logger sLogger = Logger.getLogger(PartitionGraph.class);

    private static class MapClass extends MapReduceBase
            implements Mapper<IntWritable, PageRankNode, IntWritable, PageRankNode> {
        public void map(IntWritable nid, PageRankNode node, OutputCollector<IntWritable, PageRankNode> output,
                Reporter reporter) throws IOException {
            output.collect(nid, node);
        }
    }

    private static class ReduceClass extends MapReduceBase
            implements Reducer<IntWritable, PageRankNode, IntWritable, PageRankNode> {
        public void reduce(IntWritable nid, Iterator<PageRankNode> values,
                OutputCollector<IntWritable, PageRankNode> output, Reporter reporter) throws IOException {
            while (values.hasNext()) {
                PageRankNode node = values.next();
                output.collect(nid, node);
            }
        }
    }

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new PartitionGraph(), args);
        System.exit(res);
    }

    public PartitionGraph() {
    }

    private static int printUsage() {
        System.out.println("usage: [inputDir] [outputDir] [numPartitions] [useRange?] [nodeCount]");
        ToolRunner.printGenericCommandUsage(System.out);
        return -1;
    }

    public int run(String[] args) throws IOException {
        if (args.length != 5) {
            printUsage();
            return -1;
        }

        String inPath = args[0];
        String outPath = args[1];
        int numParts = Integer.parseInt(args[2]);
        boolean useRange = Integer.parseInt(args[3]) != 0;
        int nodeCount = Integer.parseInt(args[4]);

        sLogger.info("Tool name: PartitionGraph");
        sLogger.info(" - inputDir: " + inPath);
        sLogger.info(" - outputDir: " + outPath);
        sLogger.info(" - numPartitions: " + numParts);
        sLogger.info(" - useRange?: " + useRange);
        sLogger.info(" - nodeCnt: " + nodeCount);

        JobConf conf = new JobConf(PartitionGraph.class);

        conf.setJobName("Partition Graph " + numParts);
        conf.setNumReduceTasks(numParts);

        conf.setInt("mapred.min.split.size", 1024 * 1024 * 1024);
        conf.set("mapred.child.java.opts", "-Xmx2048m");
        conf.setInt("NodeCount", nodeCount);

        FileInputFormat.setInputPaths(conf, new Path(inPath));
        FileOutputFormat.setOutputPath(conf, new Path(outPath));

        conf.setInputFormat(SequenceFileInputFormat.class);
        conf.setOutputFormat(SequenceFileOutputFormat.class);

        conf.setMapOutputKeyClass(IntWritable.class);
        conf.setMapOutputValueClass(PageRankNode.class);

        conf.setOutputKeyClass(IntWritable.class);
        conf.setOutputValueClass(PageRankNode.class);

        conf.setMapperClass(MapClass.class);
        conf.setReducerClass(ReduceClass.class);

        conf.setSpeculativeExecution(false);

        if (useRange) {
            conf.setPartitionerClass(RangePartitioner.class);
        }

        FileSystem.get(conf).delete(new Path(outPath), true);

        JobClient.runJob(conf);

        return 0;
    }
}