org.apache.hadoop.examples.pi

Class DistSum.ReduceSide.SummingReducer

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<IntWritable,SummationWritable,NullWritable,TaskResult>

org.apache.hadoop.examples.pi.DistSum.ReduceSide.SummingReducer

Enclosing class:

DistSum.ReduceSide

public static class DistSum.ReduceSide.SummingReducer
extends Reducer<IntWritable,SummationWritable,NullWritable,TaskResult>

A Reducer which computes sums

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

Reducer.Context

Constructor Summary

Constructors

Constructor and Description
DistSum.ReduceSide.SummingReducer()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	reduce(IntWritable index, Iterable<SummationWritable> sums, Reducer.Context context) This method is called once for each key.

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

DistSum.ReduceSide.SummingReducer

public DistSum.ReduceSide.SummingReducer()

Method Detail

reduce

protected void reduce(IntWritable index,
          Iterable<SummationWritable> sums,
          Reducer.Context context)
               throws IOException,
                      InterruptedException

Description copied from class: Reducer

This method is called once for each key. Most applications will define their reduce class by overriding this method. The default implementation is an identity function.

Overrides:

reduce in class Reducer<IntWritable,SummationWritable,NullWritable,TaskResult>

Throws:

IOException

InterruptedException