| Package | Description |
|---|---|
| org.apache.hadoop.mapred | |
| org.apache.hadoop.mapred.lib | |
| org.apache.hadoop.mapred.lib.aggregate | |
| org.apache.hadoop.mapred.lib.db |
| Modifier and Type | Interface and Description |
|---|---|
interface |
Mapper<K1,V1,K2,V2>
Maps input key/value pairs to a set of intermediate key/value pairs.
|
interface |
MapRunnable<K1,V1,K2,V2>
Expert: Generic interface for
Mappers. |
interface |
Partitioner<K2,V2>
Partitions the key space.
|
interface |
Reducer<K2,V2,K3,V3>
Reduces a set of intermediate values which share a key to a smaller set of
values.
|
| Modifier and Type | Class and Description |
|---|---|
class |
FixedLengthInputFormat
FixedLengthInputFormat is an input format used to read input files
which contain fixed length records.
|
class |
KeyValueTextInputFormat
An
InputFormat for plain text files. |
class |
MapReduceBase
|
class |
MapRunner<K1,V1,K2,V2>
Default
MapRunnable implementation. |
class |
TextInputFormat
An
InputFormat for plain text files. |
| Modifier and Type | Class and Description |
|---|---|
class |
BinaryPartitioner<V>
Partition
BinaryComparable keys using a configurable part of
the bytes array returned by BinaryComparable.getBytes(). |
class |
ChainMapper
The ChainMapper class allows to use multiple Mapper classes within a single
Map task.
|
class |
ChainReducer
The ChainReducer class allows to chain multiple Mapper classes after a
Reducer within the Reducer task.
|
class |
FieldSelectionMapReduce<K,V>
This class implements a mapper/reducer class that can be used to perform
field selections in a manner similar to unix cut.
|
class |
HashPartitioner<K2,V2>
Partition keys by their
Object.hashCode(). |
class |
IdentityMapper<K,V>
Implements the identity function, mapping inputs directly to outputs.
|
class |
IdentityReducer<K,V>
Performs no reduction, writing all input values directly to the output.
|
class |
InverseMapper<K,V>
A
Mapper that swaps keys and values. |
class |
KeyFieldBasedComparator<K,V>
This comparator implementation provides a subset of the features provided
by the Unix/GNU Sort.
|
class |
KeyFieldBasedPartitioner<K2,V2>
Defines a way to partition keys based on certain key fields (also see
KeyFieldBasedComparator. |
class |
LongSumReducer<K>
A
Reducer that sums long values. |
class |
MultithreadedMapRunner<K1,V1,K2,V2>
Multithreaded implementation for
MapRunnable. |
class |
NLineInputFormat
NLineInputFormat which splits N lines of input as one split.
|
class |
RegexMapper<K>
A
Mapper that extracts text matching a regular expression. |
class |
TokenCountMapper<K>
A
Mapper that maps text values into <token,freq> pairs. |
class |
TotalOrderPartitioner<K extends WritableComparable<?>,V>
Partitioner effecting a total order by reading split points from
an externally generated source.
|
| Modifier and Type | Class and Description |
|---|---|
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.
|
| Modifier and Type | Class and Description |
|---|---|
class |
DBInputFormat<T extends DBWritable> |
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