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.hbase.mapred   
org.apache.hadoop.mapred A software framework for easily writing applications which process vast amounts of data (multi-terabyte data-sets) parallelly on large clusters (thousands of nodes) built of commodity hardware in a reliable, fault-tolerant manner. 
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 Hadoop Streaming is a utility which allows users to create and run Map-Reduce jobs with any executables (e.g. 
 

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
           
 class SleepJob
          Dummy class for testing MR framefork.
static class WordCount.Reduce
          A reducer class that just emits the sum of the input values.
 

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

Classes in org.apache.hadoop.hbase.mapred that implement Reducer
 class IdentityTableReduce
          Write to table each key, record pair
 class IndexTableReduce
          Construct a Lucene document per row, which is consumed by IndexOutputFormat to build a Lucene index
 class TableReduce<K extends WritableComparable,V extends Writable>
          Write a table, sorting by the input key
 

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()
          Get the user-defined combiner class used to combine map-outputs before being sent to the reducers.
 Class<? extends Reducer> JobConf.getReducerClass()
          Get the Reducer class for the job.
 

Method parameters in org.apache.hadoop.mapred with type arguments of type Reducer
 void JobConf.setCombinerClass(Class<? extends Reducer> theClass)
          Set the user-defined combiner class used to combine map-outputs before being sent to the reducers.
 void JobConf.setReducerClass(Class<? extends Reducer> theClass)
          Set the Reducer class for the job.
 

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

Classes in org.apache.hadoop.mapred.lib that implement Reducer
 class FieldSelectionMapReduce<K extends WritableComparable,V extends Writable>
          This class implements a mapper/reducer class that can be used to perform field selections in a manner similar to unix cut.
 class IdentityReducer<K extends WritableComparable,V extends Writable>
          Performs no reduction, writing all input values directly to the output.
 class LongSumReducer<K extends WritableComparable>
          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<K1 extends WritableComparable,V1 extends Writable>
          This class implements the generic combiner of Aggregate.
 class ValueAggregatorJobBase<K1 extends WritableComparable,V1 extends Writable>
          This abstract class implements some common functionalities of the the generic mapper, reducer and combiner classes of Aggregate.
 class ValueAggregatorMapper<K1 extends WritableComparable,V1 extends Writable>
          This class implements the generic mapper 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.streaming
 

Classes in org.apache.hadoop.streaming that implement Reducer
 class PipeReducer
          A generic Reducer bridge.
 



Copyright © 2006 The Apache Software Foundation