@InterfaceAudience.Private @InterfaceStability.Unstable public class ReduceTask extends Task
Task.CombineOutputCollector<K,V>, Task.CombinerRunner<K,V>, Task.CombineValuesIterator<KEY,VALUE>, Task.Counter, Task.NewCombinerRunner<K,V>, Task.OldCombinerRunner<K,V>, Task.TaskReporter
committer, conf, DEFAULT_COMBINE_RECORDS_BEFORE_PROGRESS, extraData, failedShuffleCounter, FILESYSTEM_COUNTER_GROUP, gcUpdater, jobCleanup, jobContext, jobRunStateForCleanup, jobSetup, lDirAlloc, mapOutputFile, MERGED_OUTPUT_PREFIX, mergedMapOutputsCounter, outputFormat, PROGRESS_INTERVAL, shuffleSecret, spilledRecordsCounter, taskCleanup, taskContext, tokenSecret, umbilical
Constructor and Description |
---|
ReduceTask() |
ReduceTask(String jobFile,
TaskAttemptID taskId,
int partition,
int numMaps,
int numSlotsRequired) |
Modifier and Type | Method and Description |
---|---|
int |
getNumMaps() |
boolean |
isMapTask() |
void |
localizeConfiguration(JobConf conf)
Localize the given JobConf to be specific for this task.
|
void |
readFields(DataInput in)
Deserialize the fields of this object from
in . |
void |
run(JobConf job,
TaskUmbilicalProtocol umbilical)
Run this task as a part of the named job.
|
void |
write(DataOutput out)
Serialize the fields of this object to
out . |
createReduceContext, done, getConf, getFileSystemCounterNames, getFsStatistics, getJobFile, getJobID, getJobTokenSecret, getMapOutputFile, getNumSlotsRequired, getPartition, getPhase, getProgress, getShuffleSecret, getSkipRanges, getTaskID, initialize, isSkipping, keepTaskFiles, normalizeStatus, reportFatalError, reportNextRecordRange, runJobCleanupTask, runJobSetupTask, runTaskCleanupTask, setConf, setJobFile, setJobTokenSecret, setPhase, setShuffleSecret, setSkipping, setSkipRanges, setWriteSkipRecs, statusUpdate, toString, toWriteSkipRecs
public ReduceTask()
public ReduceTask(String jobFile, TaskAttemptID taskId, int partition, int numMaps, int numSlotsRequired)
public int getNumMaps()
public void localizeConfiguration(JobConf conf) throws IOException
localizeConfiguration
in class Task
IOException
public void write(DataOutput out) throws IOException
Writable
out
.write
in interface Writable
write
in class Task
out
- DataOuput
to serialize this object into.IOException
public void readFields(DataInput in) throws IOException
Writable
in
.
For efficiency, implementations should attempt to re-use storage in the existing object where possible.
readFields
in interface Writable
readFields
in class Task
in
- DataInput
to deseriablize this object from.IOException
public void run(JobConf job, TaskUmbilicalProtocol umbilical) throws IOException, InterruptedException, ClassNotFoundException
Task
run
in class Task
umbilical
- for progress reportsIOException
InterruptedException
ClassNotFoundException
Copyright © 2013 Apache Software Foundation. All rights reserved.