Uses of Interface
org.apache.hadoop.mapred.Reducer

Packages that use Reducer

org.apache.hadoop.contrib.utils.join
org.apache.hadoop.examples	Hadoop example code.
org.apache.hadoop.mapred	A system for scalable, fault-tolerant, distributed computation over large data collections.
org.apache.hadoop.mapred.lib	Library of generally useful mappers, reducers, and partitioners.
org.apache.hadoop.mapred.lib.aggregate	Classes for performing various counting and aggregations.
org.apache.hadoop.streaming

Uses of Reducer in org.apache.hadoop.contrib.utils.join

Classes in org.apache.hadoop.contrib.utils.join that implement Reducer

class	DataJoinMapperBase This abstract class serves as the base class for the mapper class of a data join job.
class	DataJoinReducerBase This abstract class serves as the base class for the reducer class of a data join job.
class	JobBase A common base implementing some statics collecting mechanisms that are commonly used in a typical map/reduce job.

Uses of Reducer in org.apache.hadoop.examples

Classes in org.apache.hadoop.examples that implement Reducer

static class	PiEstimator.PiReducer
static class	WordCount.Reduce A reducer class that just emits the sum of the input values.

Uses of Reducer in org.apache.hadoop.mapred

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

Class<? extends Reducer>	JobConf.getCombinerClass()
Class<? extends Reducer>	JobConf.getReducerClass()

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

void	JobConf.setCombinerClass(Class<? extends Reducer> theClass)
void	JobConf.setReducerClass(Class<? extends Reducer> theClass)

Uses of Reducer in org.apache.hadoop.mapred.lib

Classes in org.apache.hadoop.mapred.lib that implement Reducer

class	FieldSelectionMapReduce This class implements a mapper/reducer class that can be used to perform field selections in a manner similar to unix cut.
class	IdentityReducer Performs no reduction, writing all input values directly to the output.
class	LongSumReducer A Reducer that sums long values.

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

Classes in org.apache.hadoop.mapred.lib.aggregate that implement Reducer

class	ValueAggregatorCombiner This class implements the generic combiner of Abacus.
class	ValueAggregatorJobBase This abstract class implements some common functionalities of the the generic mapper, reducer and combiner classes of Abacus.
class	ValueAggregatorMapper This class implements the generic mapper of Abacus.
class	ValueAggregatorReducer This class implements the generic reducer of Abacus.

Uses of Reducer in org.apache.hadoop.streaming

Classes in org.apache.hadoop.streaming that implement Reducer

class

PipeReducer A generic Reducer bridge.