Class | Description |
---|---|
Counter |
A named counter that tracks the progress of a map/reduce job.
|
CounterGroup |
A group of
Counter s that logically belong together. |
Counters | |
ID |
A general identifier, which internally stores the id
as an integer.
|
InputFormat<K,V> |
InputFormat describes the input-specification for a
Map-Reduce job. |
InputSplit |
InputSplit represents the data to be processed by an
individual Mapper . |
Job |
The job submitter's view of the Job.
|
JobContext |
A read-only view of the job that is provided to the tasks while they
are running.
|
JobID |
JobID represents the immutable and unique identifier for
the job.
|
MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
The context that is given to the
Mapper . |
Mapper<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
Maps input key/value pairs to a set of intermediate key/value pairs.
|
OutputCommitter |
OutputCommitter describes the commit of task output for a
Map-Reduce job. |
OutputFormat<K,V> |
OutputFormat describes the output-specification for a
Map-Reduce job. |
Partitioner<KEY,VALUE> |
Partitions the key space.
|
RecordReader<KEYIN,VALUEIN> |
The record reader breaks the data into key/value pairs for input to the
Mapper . |
RecordWriter<K,V> |
RecordWriter writes the output <key, value> pairs
to an output file. |
ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
The context passed to the
Reducer . |
Reducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
Reduces a set of intermediate values which share a key to a smaller set of
values.
|
StatusReporter | |
TaskAttemptContext |
The context for task attempts.
|
TaskAttemptID |
TaskAttemptID represents the immutable and unique identifier for
a task attempt.
|
TaskID |
TaskID represents the immutable and unique identifier for
a Map or Reduce Task.
|
TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
A context object that allows input and output from the task.
|
Enum | Description |
---|---|
Job.JobState |
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