KEYIN
- the class of the input keysVALUEIN
- the class of the input valuesKEYOUT
- the class of the output keysVALUEOUT
- the class of the output valuespublic interface ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> extends TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>
Reducer
.Modifier and Type | Interface and Description |
---|---|
static interface |
ReduceContext.ValueIterator<VALUEIN>
Iterator to iterate over values for a given group of records. |
CACHE_ARCHIVES_VISIBILITIES, CACHE_FILE_VISIBILITIES, COMBINE_CLASS_ATTR, INPUT_FORMAT_CLASS_ATTR, JAR_UNPACK_PATTERN, JOB_ACL_MODIFY_JOB, JOB_ACL_VIEW_JOB, JOB_CANCEL_DELEGATION_TOKEN, JOB_NAMENODES, MAP_CLASS_ATTR, MAP_MEMORY_PHYSICAL_MB, MAP_OUTPUT_COLLECTOR_CLASS_ATTR, MAPREDUCE_TASK_CLASSPATH_PRECEDENCE, OUTPUT_FORMAT_CLASS_ATTR, PARTITIONER_CLASS_ATTR, REDUCE_CLASS_ATTR, REDUCE_MEMORY_PHYSICAL_MB, SHUFFLE_CONSUMER_PLUGIN_ATTR, USER_LOG_RETAIN_HOURS
Modifier and Type | Method and Description |
---|---|
java.lang.Iterable<VALUEIN> |
getValues()
Iterate through the values for the current key, reusing the same value
object, which is stored in the context.
|
boolean |
nextKey()
Start processing next unique key.
|
getCurrentKey, getCurrentValue, getOutputCommitter, nextKeyValue, write
getCounter, getCounter, getStatus, getTaskAttemptID, setStatus
getArchiveClassPaths, getArchiveTimestamps, getCacheArchives, getCacheFiles, getCombinerClass, getCombinerKeyGroupingComparator, getConfiguration, getCredentials, getFileClassPaths, getFileTimestamps, getGroupingComparator, getInputFormatClass, getJar, getJobID, getJobName, getJobSetupCleanupNeeded, getLocalCacheArchives, getLocalCacheFiles, getMapOutputKeyClass, getMapOutputValueClass, getMapperClass, getMaxMapAttempts, getMaxReduceAttempts, getNumReduceTasks, getOutputFormatClass, getOutputKeyClass, getOutputValueClass, getPartitionerClass, getProfileEnabled, getProfileParams, getReducerClass, getSortComparator, getSymlink, getUser, getWorkingDirectory, userClassesTakesPrecedence
boolean nextKey() throws java.io.IOException, java.lang.InterruptedException
java.io.IOException
java.lang.InterruptedException
java.lang.Iterable<VALUEIN> getValues() throws java.io.IOException, java.lang.InterruptedException
java.io.IOException
java.lang.InterruptedException
Copyright © 2009 The Apache Software Foundation