org.apache.hadoop.contrib.index.mapred
Class IndexUpdatePartitioner

java.lang.Object
  org.apache.hadoop.contrib.index.mapred.IndexUpdatePartitioner

All Implemented Interfaces:

JobConfigurable, Partitioner<Shard,IntermediateForm>

public class IndexUpdatePartitioner
extends Object
implements Partitioner<Shard,IntermediateForm>

This partitioner class puts the values of the same key - in this case the same shard - in the same partition.

Constructor Summary

IndexUpdatePartitioner()

Method Summary

void	configure(JobConf job) Initializes a new instance from a JobConf.
int	getPartition(Shard key, IntermediateForm value, int numPartitions) Get the paritition number for a given key (hence record) given the total number of partitions i.e.

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexUpdatePartitioner

public IndexUpdatePartitioner()

Method Detail

getPartition

public int getPartition(Shard key,
                        IntermediateForm value,
                        int numPartitions)

Description copied from interface: Partitioner

Get the paritition 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 interface Partitioner<Shard,IntermediateForm>

Parameters:

key - the key to be paritioned.

value - the entry value.

numPartitions - the total number of partitions.

Returns:

the partition number for the key.

configure

public void configure(JobConf job)

Description copied from interface: JobConfigurable

Initializes a new instance from a JobConf.

Specified by:

configure in interface JobConfigurable

Parameters:

job - the configuration