org.apache.hadoop.hbase.mapreduce

类 HRegionPartitioner<KEY,VALUE>

java.lang.Object

org.apache.hadoop.mapreduce.Partitioner<ImmutableBytesWritable,VALUE>

org.apache.hadoop.hbase.mapreduce.HRegionPartitioner<KEY,VALUE>

类型参数:

KEY - The type of the key.

VALUE - The type of the value.

所有已实现的接口:

org.apache.hadoop.conf.Configurable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class HRegionPartitioner<KEY,VALUE>
extends org.apache.hadoop.mapreduce.Partitioner<ImmutableBytesWritable,VALUE>
implements org.apache.hadoop.conf.Configurable

This is used to partition the output keys into groups of keys. Keys are grouped according to the regions that currently exist so that each reducer fills a single region so load is distributed.

This class is not suitable as partitioner creating hfiles for incremental bulk loads as region spread will likely change between time of hfile creation and load time. See LoadIncrementalHFiles and Bulk Load.

构造器概要

构造器

构造器和说明
HRegionPartitioner()

方法概要

方法

限定符和类型	方法和说明
org.apache.hadoop.conf.Configuration	getConf() Returns the current configuration.
int	getPartition(ImmutableBytesWritable key, VALUE value, int numPartitions) Gets the partition number for a given key (hence record) given the total number of partitions i.e. number of reduce-tasks for the job.
void	setConf(org.apache.hadoop.conf.Configuration configuration) Sets the configuration.

从类继承的方法 java.lang.Object

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

构造器详细资料

HRegionPartitioner

public HRegionPartitioner()

方法详细资料

getPartition

public int getPartition(ImmutableBytesWritable key,
               VALUE value,
               int numPartitions)

Gets 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.

指定者:

getPartition 在类中 org.apache.hadoop.mapreduce.Partitioner<ImmutableBytesWritable,VALUE>

参数:

key - The key to be partitioned.

value - The entry value.

numPartitions - The total number of partitions.

返回:

The partition number for the key.

另请参阅:

Partitioner.getPartition( java.lang.Object, java.lang.Object, int)

getConf

public org.apache.hadoop.conf.Configuration getConf()

Returns the current configuration.

指定者:

getConf 在接口中 org.apache.hadoop.conf.Configurable

返回:

The current configuration.

另请参阅:

Configurable.getConf()

setConf

public void setConf(org.apache.hadoop.conf.Configuration configuration)

Sets the configuration. This is used to determine the start keys for the given table.

指定者:

setConf 在接口中 org.apache.hadoop.conf.Configurable

参数:

configuration - The configuration to set.

另请参阅:

Configurable.setConf( org.apache.hadoop.conf.Configuration)