Package | Description |
---|---|
org.apache.hadoop.examples |
Hadoop example code.
|
org.apache.hadoop.examples.pi |
This package consists of a map/reduce application,
distbbp,
which computes exact binary digits of the mathematical constant π.
|
org.apache.hadoop.mapred | |
org.apache.hadoop.mapred.gridmix | |
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.map | |
org.apache.hadoop.mapreduce.lib.reduce | |
org.apache.hadoop.mapreduce.task |
Modifier and Type | Class and Description |
---|---|
static class |
BaileyBorweinPlouffe.BbpReducer
Reducer for concatenating map outputs.
|
static class |
QuasiMonteCarlo.QmcReducer
Reducer class for Pi estimation.
|
static class |
SecondarySort.Reduce
A reducer class that just emits the sum of the input values.
|
static class |
WordCount.IntSumReducer |
static class |
WordMean.WordMeanReducer
Performs integer summation of all the values for each key.
|
static class |
WordMedian.WordMedianReducer
Performs integer summation of all the values for each key.
|
static class |
WordStandardDeviation.WordStandardDeviationReducer
Performs integer summation of all the values for each key.
|
Modifier and Type | Class and Description |
---|---|
static class |
DistSum.ReduceSide.SummingReducer
A Reducer which computes sums
|
Modifier and Type | Method and Description |
---|---|
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE> |
Task.createReduceContext(Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
TaskAttemptID taskId,
RawKeyValueIterator rIter,
Counter inputKeyCounter,
Counter inputValueCounter,
RecordWriter<OUTKEY,OUTVALUE> output,
OutputCommitter committer,
StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass,
Class<INVALUE> valueClass) |
Modifier and Type | Class and Description |
---|---|
static class |
SleepJob.SleepReducer |
Modifier and Type | Method and 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. |
Modifier and Type | Method and 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. |
Modifier and Type | Class and 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.
|
Modifier and Type | Class and Description |
---|---|
class |
ChainReducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>
The ChainReducer class allows to chain multiple Mapper classes after a
Reducer within the Reducer task.
|
Modifier and Type | Method and Description |
---|---|
protected static void |
Chain.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.
|
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. |
Modifier and Type | Class and 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.
|
Modifier and Type | Method and Description |
---|---|
Class<? extends Reducer<?,?,?,?>> |
WrappedMapper.Context.getCombinerClass() |
Class<? extends Reducer<?,?,?,?>> |
WrappedMapper.Context.getReducerClass() |
Modifier and Type | Class and 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. |
Modifier and Type | Method and Description |
---|---|
Class<? extends Reducer<?,?,?,?>> |
WrappedReducer.Context.getCombinerClass() |
Class<? extends Reducer<?,?,?,?>> |
WrappedReducer.Context.getReducerClass() |
Modifier and Type | Method and Description |
---|---|
Class<? extends Reducer<?,?,?,?>> |
JobContextImpl.getCombinerClass()
Get the combiner class for the job.
|
Class<? extends Reducer<?,?,?,?>> |
JobContextImpl.getReducerClass()
Get the
Reducer class for the job. |
Copyright © 2013 Apache Software Foundation. All rights reserved.