org.apache.hadoop.examples.pi

Class DistSum

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.examples.pi.DistSum

All Implemented Interfaces:

Configurable, Tool

public final class DistSum
extends Configured
implements Tool

The main class for computing sums using map/reduce jobs. A sum is partitioned into jobs. A job may be executed on the map-side or on the reduce-side. A map-side job has multiple maps and zero reducer. A reduce-side job has one map and multiple reducers. Depending on the clusters status in runtime, a mix-type job may be executed on either side.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistSum.Machine Abstract machine for job execution.
static class	DistSum.MapSide A machine which does computation on the map side.
static class	DistSum.MixMachine A machine which chooses Machine in runtime according to the cluster status
static class	DistSum.ReduceSide A machine which does computation on the reduce side.

Constructor Summary

Constructors

Constructor and Description
DistSum()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args) main
int	run(String[] args)
static Map.Entry<String,TaskResult>	string2TaskResult(String s) Convert a String to a (String, TaskResult) pair
static String	taskResult2string(String name, TaskResult result) Convert a TaskResult to a String

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Constructor Detail

DistSum

public DistSum()

Method Detail

taskResult2string

public static String taskResult2string(String name,
                                       TaskResult result)

Convert a TaskResult to a String

string2TaskResult

public static Map.Entry<String,TaskResult> string2TaskResult(String s)

Convert a String to a (String, TaskResult) pair

run

public int run(String[] args)
        throws Exception

Specified by:

run in interface Tool

Throws:

Exception

main

public static void main(String[] args)
                 throws Exception

main

Throws:

Exception