org.apache.hadoop.mapred
Class Task.CombinerRunner<K,V>

java.lang.Object
  org.apache.hadoop.mapred.Task.CombinerRunner<K,V>

Direct Known Subclasses:

Task.NewCombinerRunner, Task.OldCombinerRunner

Enclosing class:

Task

@InterfaceAudience.LimitedPrivate(value="MapReduce")
@InterfaceStability.Unstable
public abstract static class Task.CombinerRunner<K,V>
extends Object

Field Summary

protected Counters.Counter	inputCounter
protected JobConf	job
protected Task.TaskReporter	reporter

Method Summary

abstract void	combine(RawKeyValueIterator iterator, OutputCollector<K,V> collector) Run the combiner over a set of inputs.
static <K,V> Task.CombinerRunner<K,V>	create(JobConf job, TaskAttemptID taskId, Counters.Counter inputCounter, Task.TaskReporter reporter, OutputCommitter committer)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

inputCounter

protected final Counters.Counter inputCounter

job

protected final JobConf job

reporter

protected final Task.TaskReporter reporter

Method Detail

combine

public abstract void combine(RawKeyValueIterator iterator,
                             OutputCollector<K,V> collector)
                      throws IOException,
                             InterruptedException,
                             ClassNotFoundException

Run the combiner over a set of inputs.

Parameters:

iterator - the key/value pairs to use as input

collector - the output collector

Throws:

IOException

InterruptedException

ClassNotFoundException

create

public static <K,V> Task.CombinerRunner<K,V> create(JobConf job,
                                                    TaskAttemptID taskId,
                                                    Counters.Counter inputCounter,
                                                    Task.TaskReporter reporter,
                                                    OutputCommitter committer)
                                       throws ClassNotFoundException

Throws:

ClassNotFoundException