Uses of Class
org.apache.hadoop.mapreduce.Reducer

Packages that use Reducer

Package	Description
org.apache.hadoop.mapreduce
org.apache.hadoop.mapreduce.lib.aggregate
org.apache.hadoop.mapreduce.lib.chain
org.apache.hadoop.mapreduce.lib.fieldsel
org.apache.hadoop.mapreduce.lib.reduce

Uses of Reducer in org.apache.hadoop.mapreduce

Methods in org.apache.hadoop.mapreduce that return types with arguments of type Reducer

Modifier and Type	Method	Description
Class<? extends Reducer<?,?,?,?>>	JobContext.getCombinerClass()	Get the combiner class for the job.
Class<? extends Reducer<?,?,?,?>>	JobContext.getReducerClass()	Get the Reducer class for the job.

Method parameters in org.apache.hadoop.mapreduce with type arguments of type Reducer

Modifier and Type	Method	Description
void	Job.setCombinerClass(Class<? extends Reducer> cls)	Set the combiner class for the job.
void	Job.setReducerClass(Class<? extends Reducer> cls)	Set the Reducer for the job.

Uses of Reducer in org.apache.hadoop.mapreduce.lib.aggregate

Subclasses of Reducer in org.apache.hadoop.mapreduce.lib.aggregate

Modifier and Type	Class	Description
class	ValueAggregatorCombiner<K1 extends WritableComparable<?>,V1 extends Writable>	This class implements the generic combiner of Aggregate.
class	ValueAggregatorReducer<K1 extends WritableComparable<?>,V1 extends Writable>	This class implements the generic reducer of Aggregate.

Uses of Reducer in org.apache.hadoop.mapreduce.lib.chain

Subclasses of Reducer in org.apache.hadoop.mapreduce.lib.chain

Modifier and Type	Class	Description
class	ChainReducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	The ChainReducer class allows to chain multiple Mapper classes after a Reducer within the Reducer task.

Method parameters in org.apache.hadoop.mapreduce.lib.chain with type arguments of type Reducer

Modifier and Type	Method	Description
static void	ChainReducer.setReducer(Job job, Class<? extends Reducer> klass, Class<?> inputKeyClass, Class<?> inputValueClass, Class<?> outputKeyClass, Class<?> outputValueClass, Configuration reducerConf)	Sets the Reducer class to the chain job.

Uses of Reducer in org.apache.hadoop.mapreduce.lib.fieldsel

Subclasses of Reducer in org.apache.hadoop.mapreduce.lib.fieldsel

Modifier and Type	Class	Description
class	FieldSelectionReducer<K,V>	This class implements a reducer class that can be used to perform field selections in a manner similar to unix cut.

Uses of Reducer in org.apache.hadoop.mapreduce.lib.reduce

Subclasses of Reducer in org.apache.hadoop.mapreduce.lib.reduce

Modifier and Type	Class	Description
class	IntSumReducer<Key>
class	LongSumReducer<KEY>
class	WrappedReducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	A Reducer which wraps a given one to allow for custom Reducer.Context implementations.