org.apache.hadoop.hbase.mapreduce

Class CellSortReducer

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell,org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell>

org.apache.hadoop.hbase.mapreduce.CellSortReducer

@InterfaceAudience.Public
public class CellSortReducer
extends org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell,org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell>

Emits sorted Cells. Reads in all Cells from passed Iterator, sorts them, then emits Cells in sorted order. If lots of columns per row, it will use lots of memory sorting.

See Also:

HFileOutputFormat2

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

org.apache.hadoop.mapreduce.Reducer.Context

Constructor Summary

Constructors

Constructor and Description
CellSortReducer()

Method Summary

Modifier and Type	Method and Description
protected void	reduce(org.apache.hadoop.hbase.io.ImmutableBytesWritable row, Iterable<org.apache.hadoop.hbase.Cell> kvs, org.apache.hadoop.mapreduce.Reducer.Context context)

Methods inherited from class org.apache.hadoop.mapreduce.Reducer

cleanup, run, setup

Methods inherited from class java.lang.Object

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

Constructor Detail

CellSortReducer

public CellSortReducer()

Method Detail

reduce

protected void reduce(org.apache.hadoop.hbase.io.ImmutableBytesWritable row,
                      Iterable<org.apache.hadoop.hbase.Cell> kvs,
                      org.apache.hadoop.mapreduce.Reducer.Context context)
               throws IOException,
                      InterruptedException

Overrides:

reduce in class org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell,org.apache.hadoop.hbase.io.ImmutableBytesWritable,org.apache.hadoop.hbase.Cell>

Throws:

IOException

InterruptedException