org.apache.hadoop.hbase.mapreduce

Class KeyValueSortReducer

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<ImmutableBytesWritable,KeyValue,ImmutableBytesWritable,KeyValue>

org.apache.hadoop.hbase.mapreduce.KeyValueSortReducer

@InterfaceAudience.Public
@InterfaceStability.Stable
public class KeyValueSortReducer
extends org.apache.hadoop.mapreduce.Reducer<ImmutableBytesWritable,KeyValue,ImmutableBytesWritable,KeyValue>

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

See Also:

HFileOutputFormat

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
KeyValueSortReducer()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	reduce(ImmutableBytesWritable row, Iterable<KeyValue> 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

KeyValueSortReducer

public KeyValueSortReducer()

Method Detail

reduce

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

Overrides:

reduce in class org.apache.hadoop.mapreduce.Reducer<ImmutableBytesWritable,KeyValue,ImmutableBytesWritable,KeyValue>

Throws:

IOException

InterruptedException