@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, 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) |
void |
run(JobConf job,
TaskUmbilicalProtocol umbilical)
Run this task as a part of the named job.
|
void |
setLocalMapFiles(Map<TaskAttemptID,MapOutputFile> mapFiles)
Register the set of mapper outputs created by a LocalJobRunner-based
job with this ReduceTask so it knows where to fetch from.
|
void |
write(DataOutput out) |
createReduceContext, done, getConf, getEncryptedSpillKey, getFileSystemCounterNames, getFsStatistics, getJobFile, getJobID, getJobTokenSecret, getMapOutputFile, getNumSlotsRequired, getPartition, getPhase, getProgress, getShuffleSecret, getSkipRanges, getTaskID, initialize, isSkipping, keepTaskFiles, normalizeStatus, reportFatalError, reportNextRecordRange, runJobCleanupTask, runJobSetupTask, runTaskCleanupTask, setConf, setEncryptedSpillKey, 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 void setLocalMapFiles(Map<TaskAttemptID,MapOutputFile> mapFiles)
public int getNumMaps()
public void localizeConfiguration(JobConf conf) throws IOException
localizeConfiguration
in class Task
IOException
public void write(DataOutput out) throws IOException
write
in interface org.apache.hadoop.io.Writable
write
in class Task
IOException
public void readFields(DataInput in) throws IOException
readFields
in interface org.apache.hadoop.io.Writable
readFields
in class Task
IOException
public void run(JobConf job, TaskUmbilicalProtocol umbilical) throws IOException, InterruptedException, ClassNotFoundException
Task
run
in class Task
umbilical
- for progress reportsIOException
InterruptedException
ClassNotFoundException
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