org.beymani.proximity.NeighborDensity.java Source code

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Here is the source code for org.beymani.proximity.NeighborDensity.java

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/*
 * beymani: Outlier and anamoly detection 
 * Author: Pranab Ghosh
 * 
 * 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 org.beymani.proximity;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.chombo.util.SecondarySort;
import org.chombo.util.TextInt;
import org.chombo.util.Tuple;
import org.chombo.util.Utility;

/**
 * @author pranab
 *
 */
public class NeighborDensity extends Configured implements Tool {

    @Override
    public int run(String[] args) throws Exception {
        Job job = new Job(getConf());
        String jobName = "Nearest neighbour density";
        job.setJobName(jobName);

        job.setJarByClass(NeighborDensity.class);

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        job.setMapperClass(NeighborDensity.GroupingMapper.class);
        job.setReducerClass(NeighborDensity.GroupingReducer.class);

        job.setMapOutputKeyClass(TextInt.class);
        job.setMapOutputValueClass(Tuple.class);

        job.setOutputKeyClass(NullWritable.class);
        job.setOutputValueClass(Text.class);

        job.setGroupingComparatorClass(SecondarySort.TextIntIdPairGroupComprator.class);
        job.setPartitionerClass(SecondarySort.TextIntIdPairTuplePartitioner.class);

        Utility.setConfiguration(job.getConfiguration());

        job.setNumReduceTasks(job.getConfiguration().getInt("num.reducer", 1));

        int status = job.waitForCompletion(true) ? 0 : 1;
        return status;
    }

    /**
     * @author pranab
     *
     */
    public static class GroupingMapper extends Mapper<LongWritable, Text, TextInt, Tuple> {
        private String fieldDelimRegex;
        private String fieldDelim;
        private boolean isDensitySplit;
        private TextInt outKey = new TextInt();
        private Tuple outVal = new Tuple();
        private String[] items;
        private static final Logger LOG = Logger.getLogger(GroupingMapper.class);

        protected void setup(Context context) throws IOException, InterruptedException {
            Configuration conf = context.getConfiguration();
            fieldDelim = conf.get("field.delim", ",");
            fieldDelimRegex = conf.get("field.delim.regex", "\\[\\]");
            String densityFilePrefix = conf.get("density.file.prefix", "first");
            isDensitySplit = ((FileSplit) context.getInputSplit()).getPath().getName()
                    .startsWith(densityFilePrefix);
            if (conf.getBoolean("debug.on", false)) {
                LOG.setLevel(Level.DEBUG);
            }
            LOG.debug("isDensitySplit:" + isDensitySplit);
        }

        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            items = value.toString().split(fieldDelimRegex);
            outVal.initialize();
            if (isDensitySplit) {
                outKey.set(items[0], 0);
                outVal.add(Integer.parseInt(items[1]));
            } else {
                outKey.set(items[0], 1);
                outVal.add(items[1], Integer.parseInt(items[2]));
            }
            context.write(outKey, outVal);
        }

    }

    /**
     * @author pranab
     *
     */
    public static class GroupingReducer extends Reducer<TextInt, Tuple, NullWritable, Text> {
        private String entityID;
        private int density;
        private String group;
        private Text outVal = new Text();
        private String fieldDelim;
        private static final Logger LOG = Logger.getLogger(GroupingReducer.class);

        /* (non-Javadoc)
         * @see org.apache.hadoop.mapreduce.Reducer#setup(org.apache.hadoop.mapreduce.Reducer.Context)
         */
        protected void setup(Context context) throws IOException, InterruptedException {
            Configuration conf = context.getConfiguration();
            fieldDelim = conf.get("field.delim", "\\[\\]");
            if (conf.getBoolean("debug.on", false)) {
                LOG.setLevel(Level.DEBUG);
            }
        }

        /* (non-Javadoc)
         * @see org.apache.hadoop.mapreduce.Reducer#reduce(KEYIN, java.lang.Iterable, org.apache.hadoop.mapreduce.Reducer.Context)
         */
        protected void reduce(TextInt key, Iterable<Tuple> values, Context context)
                throws IOException, InterruptedException {
            entityID = key.getFirst().toString();
            LOG.debug("entityID:" + entityID);

            for (Tuple val : values) {
                LOG.debug("value tuple size:" + val.getSize());
                if (val.getSize() == 1) {
                    density = val.getInt(0);
                } else {
                    group = val.getString(0);
                    outVal.set(group + fieldDelim + entityID + fieldDelim + density);
                    context.write(NullWritable.get(), outVal);
                }
            }
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        int exitCode = ToolRunner.run(new NeighborDensity(), args);
        System.exit(exitCode);
    }

}