org.apache.mahout.fpm.pfpgrowth
Class ParallelCountingReducer

java.lang.Object
  extended by org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>
      extended by org.apache.mahout.fpm.pfpgrowth.ParallelCountingReducer

public class ParallelCountingReducer
extends org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>

sums up the item count and output the item and the count This can also be used as a local Combiner. A simple summing reducer


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer
org.apache.hadoop.mapreduce.Reducer.Context
 
Constructor Summary
ParallelCountingReducer()
           
 
Method Summary
protected  void reduce(org.apache.hadoop.io.Text key, Iterable<org.apache.hadoop.io.LongWritable> values, org.apache.hadoop.mapreduce.Reducer.Context context)
           
 
Methods inherited from class org.apache.hadoop.mapreduce.Reducer
cleanup, run, setup
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ParallelCountingReducer

public ParallelCountingReducer()
Method Detail

reduce

protected void reduce(org.apache.hadoop.io.Text key,
                      Iterable<org.apache.hadoop.io.LongWritable> values,
                      org.apache.hadoop.mapreduce.Reducer.Context context)
               throws IOException,
                      InterruptedException
Overrides:
reduce in class org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>
Throws:
IOException
InterruptedException


Copyright © 2008–2014 The Apache Software Foundation. All rights reserved.