/*
* 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.io.WritableComparable;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Partitioner;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Reducer.Context;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.chombo.util.TextInt;
import org.chombo.util.Utility;
/**
* @author pranab
*
*/
public class AverageDistance extends Configured implements Tool {
@Override
public int run(String[] args) throws Exception {
Job job = new Job(getConf());
String jobName = "Nearest neighbour stat calculation MR";
job.setJobName(jobName);
job.setJarByClass(AverageDistance.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
job.setMapperClass(AverageDistance.TopMatchesMapper.class);
job.setReducerClass(AverageDistance.TopMatchesReducer.class);
job.setMapOutputKeyClass(TextInt.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(NullWritable.class);
job.setOutputValueClass(Text.class);
job.setGroupingComparatorClass(IdRankGroupComprator.class);
job.setPartitionerClass(IdRankPartitioner.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 TopMatchesMapper extends Mapper<LongWritable, Text, TextInt, Text> {
private String srcEntityId;
private String trgEntityId;
private int rank;
private TextInt outKey = new TextInt();
private Text outVal = new Text();
private String fieldDelimRegex;
private String fieldDelim;
protected void setup(Context context) throws IOException, InterruptedException {
fieldDelim = context.getConfiguration().get("field.delim", ",");
fieldDelimRegex = context.getConfiguration().get("field.delim.regex", "\\[\\]");
}
@Override
protected void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String[] items = value.toString().split(fieldDelimRegex);
srcEntityId = items[0];
trgEntityId = items[1];
rank = Integer.parseInt(items[items.length - 1]);
outKey.set(srcEntityId, rank);
outVal.set(trgEntityId + fieldDelim + items[items.length - 1]);
context.write(outKey, outVal);
}
}
/**
* @author pranab
*
*/
public static class TopMatchesReducer extends Reducer<TextInt, Text, NullWritable, Text> {
private int topMatchCount;
private String trgEntityId;
private String srcEntityId;
private int count;
private int sum;
private int dist;
private Text outVal = new Text();
private boolean doAverage;
private boolean doDensity;
private boolean doGrouping;
private int densityScale;
private int avg;
private int density;
private String fieldDelim;
private String fieldDelimRegex;
private String[] items;
private int grMemeberIndex;
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Reducer#setup(org.apache.hadoop.mapreduce.Reducer.Context)
*/
protected void setup(Context context) throws IOException, InterruptedException {
Configuration config = context.getConfiguration();
fieldDelim = config.get("field.delim", ",");
fieldDelimRegex = config.get("field.delim.regex", "\\[\\]");
topMatchCount = config.getInt("avd.top.match.count", 10);
doAverage = config.getBoolean("avd.match.average", true);
doDensity = config.getBoolean("avd.top.match.density", false);
doGrouping = config.getBoolean("avd.top.match.grouping", false);
densityScale = config.getInt("avd.top.match.density.scale", 1000000);
}
/* (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<Text> values, Context context)
throws IOException, InterruptedException {
srcEntityId = key.getFirst().toString();
count = 0;
sum = 0;
grMemeberIndex = 0;
if (doGrouping) {
//group leader
outVal.set(srcEntityId + fieldDelim + srcEntityId + fieldDelim + grMemeberIndex);
context.write(NullWritable.get(), outVal);
++grMemeberIndex;
}
for (Text value : values){
items = value.toString().split(fieldDelimRegex);
if (doAverage || doDensity) {
//average distance or density
dist = Integer.parseInt(items[1]);
sum += dist;
} else {
//neighborhood group - entity, group, memebership number
trgEntityId = items[0];
outVal.set(trgEntityId + fieldDelim + srcEntityId + fieldDelim + grMemeberIndex);
context.write(NullWritable.get(), outVal);
++grMemeberIndex;
}
if (++count == topMatchCount){
break;
}
}
if (doAverage || doDensity) {
avg = sum / count;
}
if (doDensity) {
avg = avg == 0 ? 1 : avg;
density = densityScale / avg;
outVal.set(srcEntityId +fieldDelim + density);
} else if (doAverage) {
outVal.set(srcEntityId + fieldDelim + avg);
}
if (doAverage || doDensity) {
context.write(NullWritable.get(), outVal);
}
}
}
/**
* @author pranab
*
*/
public static class IdRankPartitioner extends Partitioner<TextInt, Text> {
@Override
public int getPartition(TextInt key, Text value, int numPartitions) {
//consider only base part of key
Text id = key.getFirst();
return id.hashCode() % numPartitions;
}
}
/**
* @author pranab
*
*/
public static class IdRankGroupComprator extends WritableComparator {
protected IdRankGroupComprator() {
super(TextInt.class, true);
}
@Override
public int compare(WritableComparable w1, WritableComparable w2) {
//consider only the base part of the key
Text t1 = ((TextInt)w1).getFirst();
Text t2 = ((TextInt)w2).getFirst();
int comp = t1.compareTo(t2);
return comp;
}
}
/**
* @param args
*/
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new AverageDistance(), args);
System.exit(exitCode);
}
}