org.apache.nutch.mapReduce
Interface Partitioner

All Superinterfaces:

Configurable

All Known Implementing Classes:

HashPartitioner

public interface Partitioner

extends Configurable

Partitions the key space. A partition is created for each reduce task.

Method Summary

int	getPartition(WritableComparable key, int numPartitions) Returns the paritition number for a given key given the total number of partitions.

Methods inherited from interface org.apache.nutch.mapReduce.Configurable

configure

Method Detail

getPartition

public int getPartition(WritableComparable key,
                        int numPartitions)

Returns the paritition number for a given key given the total number of partitions. Typically a hash function on a all or a subset of the key.

Parameters:

key - the key

numPartitions - the number of partitions

Returns:

the partition number