edu.yale.cs.hadoopdb.benchmark.SelectionTaskHDFS.java Source code

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Here is the source code for edu.yale.cs.hadoopdb.benchmark.SelectionTaskHDFS.java

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/**
 * Copyright 2009 HadoopDB Team (http://db.cs.yale.edu/hadoopdb/hadoopdb.html)
 *
 * 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.yale.cs.hadoopdb.benchmark;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
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.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.util.ToolRunner;

import edu.yale.cs.hadoopdb.exec.HDFSJobBase;
import edu.yale.cs.hadoopdb.util.BenchmarkUtils;
import edu.yale.cs.hadoopdb.util.HDFSUtil;

/**
 * Adapted from Andy Pavlo's code 
 * http://database.cs.brown.edu/projects/mapreduce-vs-dbms/
 */
public class SelectionTaskHDFS extends HDFSJobBase {

    public static final String PAGE_RANK_VALUE_PARAM = "page.rank.value";

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

    @Override
    protected JobConf configureJob(String... args) throws IOException {

        JobConf conf = new JobConf(getConf(), this.getClass());
        conf.setJobName("selection_hdfs");

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

        conf.setMapperClass(Map.class);
        conf.setNumReduceTasks(0);

        conf.setInputFormat(TextInputFormat.class);
        conf.setOutputFormat(TextOutputFormat.class);
        if (args.length < 3) {
            throw new RuntimeException("Incorrect arguments provided for " + this.getClass());
        }

        conf.set(PAGE_RANK_VALUE_PARAM, args[0]);
        FileInputFormat.setInputPaths(conf, new Path(args[1]));

        // OUTPUT properties
        Path outputPath = new Path(args[2]);
        HDFSUtil.deletePath(outputPath);
        FileOutputFormat.setOutputPath(conf, outputPath);

        return conf;

    }

    static class Map extends MapReduceBase implements Mapper<LongWritable, Text, Text, IntWritable> {
        protected int PAGE_RANK_VALUE;

        public void configure(JobConf job) {
            super.configure(job);

            String pageRank = job.get(PAGE_RANK_VALUE_PARAM);
            PAGE_RANK_VALUE = Integer.parseInt(pageRank);
        }

        protected Text outputKey = new Text();
        protected IntWritable outputValue = new IntWritable();

        public void map(LongWritable key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter)
                throws IOException {

            // Rankings: pageRank | pageURL | avgDuration
            String fields[] = BenchmarkUtils.DELIMITER_PATTERN.split(value.toString());

            int pageRank = Integer.valueOf(fields[0]);
            if (pageRank > PAGE_RANK_VALUE) {
                outputKey.set(fields[1]);
                outputValue.set(pageRank);
                output.collect(outputKey, outputValue);
            }
        }
    }

    @Override
    protected int printUsage() {
        System.out.println("<page_rank_value> <input_dir> <output_dir>");
        return -1;
    }

}