org.apache.hadoop.examples.terasort

Class TeraSort.SimplePartitioner

java.lang.Object

org.apache.hadoop.mapreduce.Partitioner<Text,Text>

org.apache.hadoop.examples.terasort.TeraSort.SimplePartitioner

All Implemented Interfaces:

Configurable

Enclosing class:

TeraSort

public static class TeraSort.SimplePartitioner
extends Partitioner<Text,Text>
implements Configurable

A total order partitioner that assigns keys based on their first PREFIX_LENGTH bytes, assuming a flat distribution.

Constructor Summary

Constructors

Constructor and Description
TeraSort.SimplePartitioner()

Method Summary

Methods

Modifier and Type	Method and Description
Configuration	getConf() Return the configuration used by this object.
int	getPartition(Text key, Text value, int numPartitions) Get the partition number for a given key (hence record) given the total number of partitions i.e.
void	setConf(Configuration conf) Set the configuration to be used by this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

TeraSort.SimplePartitioner

public TeraSort.SimplePartitioner()

Method Detail

setConf

public void setConf(Configuration conf)

Description copied from interface: Configurable

Set the configuration to be used by this object.

Specified by:

setConf in interface Configurable

getConf

public Configuration getConf()

Description copied from interface: Configurable

Return the configuration used by this object.

Specified by:

getConf in interface Configurable

getPartition

public int getPartition(Text key,
               Text value,
               int numPartitions)

Description copied from class: Partitioner

Get the partition number for a given key (hence record) given the total number of partitions i.e. number of reduce-tasks for the job.

Typically a hash function on a all or a subset of the key.

Specified by:

getPartition in class Partitioner<Text,Text>

Parameters:

key - the key to be partioned.

value - the entry value.

numPartitions - the total number of partitions.

Returns:

the partition number for the key.