org.apache.hadoop.mapreduce.lib.reduce

Class WrappedReducer.Context

java.lang.Object

org.apache.hadoop.mapreduce.Reducer.Context

org.apache.hadoop.mapreduce.lib.reduce.WrappedReducer.Context

All Implemented Interfaces:

JobContext, ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>, TaskAttemptContext, TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>, org.apache.hadoop.util.Progressable

Enclosing class:

WrappedReducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

public class WrappedReducer.Context
extends Reducer.Context

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.mapreduce.ReduceContext

ReduceContext.ValueIterator<VALUEIN>

Field Summary

Fields

Modifier and Type	Field and Description
protected ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	reduceContext

Fields inherited from interface org.apache.hadoop.mapreduce.JobContext

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

Constructor Summary

Constructors

Constructor and Description
WrappedReducer.Context(ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> reduceContext)

Method Summary

Methods

Modifier and Type	Method and Description
org.apache.hadoop.fs.Path[]	getArchiveClassPaths() Get the archive entries in classpath as an array of Path
java.lang.String[]	getArchiveTimestamps() Get the timestamps of the archives.
java.net.URI[]	getCacheArchives() Get cache archives set in the Configuration
java.net.URI[]	getCacheFiles() Get cache files set in the Configuration
java.lang.Class<? extends Reducer<?,?,?,?>>	getCombinerClass() Get the combiner class for the job.
org.apache.hadoop.io.RawComparator<?>	getCombinerKeyGroupingComparator() Get the user defined RawComparator comparator for grouping keys of inputs to the combiner.
org.apache.hadoop.conf.Configuration	getConfiguration() Return the configuration for the job.
Counter	getCounter(java.lang.Enum counterName) Get the Counter for the given counterName.
Counter	getCounter(java.lang.String groupName, java.lang.String counterName) Get the Counter for the given groupName and counterName.
org.apache.hadoop.security.Credentials	getCredentials() Get credentials for the job.
KEYIN	getCurrentKey() Get the current key.
VALUEIN	getCurrentValue() Get the current value.
org.apache.hadoop.fs.Path[]	getFileClassPaths() Get the file entries in classpath as an array of Path
java.lang.String[]	getFileTimestamps() Get the timestamps of the files.
org.apache.hadoop.io.RawComparator<?>	getGroupingComparator() Get the user defined RawComparator comparator for grouping keys of inputs to the reduce.
java.lang.Class<? extends InputFormat<?,?>>	getInputFormatClass() Get the InputFormat class for the job.
java.lang.String	getJar() Get the pathname of the job's jar.
JobID	getJobID() Get the unique ID for the job.
java.lang.String	getJobName() Get the user-specified job name.
boolean	getJobSetupCleanupNeeded() Get whether job-setup and job-cleanup is needed for the job
org.apache.hadoop.fs.Path[]	getLocalCacheArchives() Return the path array of the localized caches
org.apache.hadoop.fs.Path[]	getLocalCacheFiles() Return the path array of the localized files
java.lang.Class<?>	getMapOutputKeyClass() Get the key class for the map output data.
java.lang.Class<?>	getMapOutputValueClass() Get the value class for the map output data.
java.lang.Class<? extends Mapper<?,?,?,?>>	getMapperClass() Get the Mapper class for the job.
int	getMaxMapAttempts() Get the configured number of maximum attempts that will be made to run a
int	getMaxReduceAttempts() Get the configured number of maximum attempts that will be made to run a
int	getNumReduceTasks() Get configured the number of reduce tasks for this job.
OutputCommitter	getOutputCommitter() Get the OutputCommitter for the task-attempt.
java.lang.Class<? extends OutputFormat<?,?>>	getOutputFormatClass() Get the OutputFormat class for the job.
java.lang.Class<?>	getOutputKeyClass() Get the key class for the job output data.
java.lang.Class<?>	getOutputValueClass() Get the value class for job outputs.
java.lang.Class<? extends Partitioner<?,?>>	getPartitionerClass() Get the Partitioner class for the job.
boolean	getProfileEnabled() Get whether the task profiling is enabled.
java.lang.String	getProfileParams()
java.lang.Class<? extends Reducer<?,?,?,?>>	getReducerClass() Get the Reducer class for the job.
org.apache.hadoop.io.RawComparator<?>	getSortComparator() Get the RawComparator comparator used to compare keys.
java.lang.String	getStatus() Get the last set status message.
boolean	getSymlink() This method checks to see if symlinks are to be create for the localized cache files in the current working directory
TaskAttemptID	getTaskAttemptID() Get the unique name for this task attempt.
java.lang.String	getUser() Get the reported username for this job.
java.lang.Iterable<VALUEIN>	getValues() Iterate through the values for the current key, reusing the same value object, which is stored in the context.
org.apache.hadoop.fs.Path	getWorkingDirectory() Get the current working directory for the default file system.
boolean	nextKey() Start processing next unique key.
boolean	nextKeyValue() Advance to the next key, value pair, returning null if at end.
void	progress()
void	setStatus(java.lang.String msg) Set the current status of the task to the given string.
boolean	userClassesTakesPrecedence() Get the boolean value for the property that specifies which classpath takes precedence when tasks are launched.
void	write(KEYOUT key, VALUEOUT value) Generate an output key/value pair.

Methods inherited from class java.lang.Object

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

Field Detail

reduceContext

protected ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> reduceContext

Constructor Detail

WrappedReducer.Context

public WrappedReducer.Context(ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> reduceContext)

Method Detail

getCurrentKey

public KEYIN getCurrentKey()
                    throws java.io.IOException,
                           java.lang.InterruptedException

Description copied from interface: TaskInputOutputContext

Get the current key.

Returns:

the current key object or null if there isn't one

Throws:

java.io.IOException

java.lang.InterruptedException

getCurrentValue

public VALUEIN getCurrentValue()
                        throws java.io.IOException,
                               java.lang.InterruptedException

Description copied from interface: TaskInputOutputContext

Get the current value.

Returns:

the value object that was read into

Throws:

java.io.IOException

java.lang.InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException,
                            java.lang.InterruptedException

Description copied from interface: TaskInputOutputContext

Advance to the next key, value pair, returning null if at end.

Returns:

the key object that was read into, or null if no more

Throws:

java.io.IOException

java.lang.InterruptedException

getCounter

public Counter getCounter(java.lang.Enum counterName)

Description copied from interface: TaskAttemptContext

Get the Counter for the given counterName.

Parameters:

counterName - counter name

Returns:

the Counter for the given counterName

getCounter

public Counter getCounter(java.lang.String groupName,
                 java.lang.String counterName)

Description copied from interface: TaskAttemptContext

Get the Counter for the given groupName and counterName.

counterName - counter name

Returns:

the Counter for the given groupName and counterName

getOutputCommitter

public OutputCommitter getOutputCommitter()

Description copied from interface: TaskInputOutputContext

Get the OutputCommitter for the task-attempt.

Returns:

the OutputCommitter for the task-attempt

write

public void write(KEYOUT key,
         VALUEOUT value)
           throws java.io.IOException,
                  java.lang.InterruptedException

Description copied from interface: TaskInputOutputContext

Generate an output key/value pair.

Throws:

java.io.IOException

java.lang.InterruptedException

getStatus

public java.lang.String getStatus()

Description copied from interface: TaskAttemptContext

Get the last set status message.

Returns:

the current status message

getTaskAttemptID

public TaskAttemptID getTaskAttemptID()

Description copied from interface: TaskAttemptContext

Get the unique name for this task attempt.

setStatus

public void setStatus(java.lang.String msg)

Description copied from interface: TaskAttemptContext

Set the current status of the task to the given string.

getArchiveClassPaths

public org.apache.hadoop.fs.Path[] getArchiveClassPaths()

Description copied from interface: JobContext

Get the archive entries in classpath as an array of Path

getArchiveTimestamps

public java.lang.String[] getArchiveTimestamps()

Description copied from interface: JobContext

Get the timestamps of the archives. Used by internal

Returns:

a string array of timestamps

getCacheArchives

public java.net.URI[] getCacheArchives()
                                throws java.io.IOException

Description copied from interface: JobContext

Get cache archives set in the Configuration

Returns:

A URI array of the caches set in the Configuration

Throws:

java.io.IOException

getCacheFiles

public java.net.URI[] getCacheFiles()
                             throws java.io.IOException

Description copied from interface: JobContext

Get cache files set in the Configuration

Throws:

java.io.IOException

getCombinerClass

public java.lang.Class<? extends Reducer<?,?,?,?>> getCombinerClass()
                                                             throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the combiner class for the job.

Returns:

the combiner class for the job.

Throws:

java.lang.ClassNotFoundException

getConfiguration

public org.apache.hadoop.conf.Configuration getConfiguration()

Description copied from interface: JobContext

Return the configuration for the job.

Returns:

the shared configuration object

getFileClassPaths

public org.apache.hadoop.fs.Path[] getFileClassPaths()

Description copied from interface: JobContext

Get the file entries in classpath as an array of Path

getFileTimestamps

public java.lang.String[] getFileTimestamps()

Description copied from interface: JobContext

Get the timestamps of the files. Used by internal

Returns:

a string array of timestamps

getCombinerKeyGroupingComparator

public org.apache.hadoop.io.RawComparator<?> getCombinerKeyGroupingComparator()

Description copied from interface: JobContext

Get the user defined RawComparator comparator for grouping keys of inputs to the combiner.

Returns:

comparator set by the user for grouping values.

See Also:

Job.setCombinerKeyGroupingComparatorClass(Class)

getGroupingComparator

public org.apache.hadoop.io.RawComparator<?> getGroupingComparator()

Description copied from interface: JobContext

Get the user defined RawComparator comparator for grouping keys of inputs to the reduce.

Returns:

comparator set by the user for grouping values.

See Also:

for details., JobContext.getCombinerKeyGroupingComparator()

getInputFormatClass

public java.lang.Class<? extends InputFormat<?,?>> getInputFormatClass()
                                                                throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the InputFormat class for the job.

Returns:

the InputFormat class for the job.

Throws:

java.lang.ClassNotFoundException

getJar

public java.lang.String getJar()

Description copied from interface: JobContext

Get the pathname of the job's jar.

Returns:

the pathname

getJobID

public JobID getJobID()

Description copied from interface: JobContext

Get the unique ID for the job.

Returns:

the object with the job id

getJobName

public java.lang.String getJobName()

Description copied from interface: JobContext

Get the user-specified job name. This is only used to identify the job to the user.

Returns:

the job's name, defaulting to "".

userClassesTakesPrecedence

public boolean userClassesTakesPrecedence()

Description copied from interface: JobContext

Get the boolean value for the property that specifies which classpath takes precedence when tasks are launched. True - user's classes takes precedence. False - system's classes takes precedence.

Returns:

true if user's classes should take precedence

getJobSetupCleanupNeeded

public boolean getJobSetupCleanupNeeded()

Description copied from interface: JobContext

Get whether job-setup and job-cleanup is needed for the job

Returns:

boolean

getLocalCacheArchives

public org.apache.hadoop.fs.Path[] getLocalCacheArchives()
                                                  throws java.io.IOException

Description copied from interface: JobContext

Return the path array of the localized caches

Returns:

A path array of localized caches

Throws:

java.io.IOException

getLocalCacheFiles

public org.apache.hadoop.fs.Path[] getLocalCacheFiles()
                                               throws java.io.IOException

Description copied from interface: JobContext

Return the path array of the localized files

Returns:

A path array of localized files

Throws:

java.io.IOException

getMapOutputKeyClass

public java.lang.Class<?> getMapOutputKeyClass()

Description copied from interface: JobContext

Get the key class for the map output data. If it is not set, use the (final) output key class. This allows the map output key class to be different than the final output key class.

Returns:

the map output key class.

getMapOutputValueClass

public java.lang.Class<?> getMapOutputValueClass()

Description copied from interface: JobContext

Get the value class for the map output data. If it is not set, use the (final) output value class This allows the map output value class to be different than the final output value class.

Returns:

the map output value class.

getMapperClass

public java.lang.Class<? extends Mapper<?,?,?,?>> getMapperClass()
                                                          throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the Mapper class for the job.

Returns:

the Mapper class for the job.

Throws:

java.lang.ClassNotFoundException

getMaxMapAttempts

public int getMaxMapAttempts()

Description copied from interface: JobContext

Get the configured number of maximum attempts that will be made to run a

Returns:

the max number of attempts per map task.

getMaxReduceAttempts

public int getMaxReduceAttempts()

Description copied from interface: JobContext

Get the configured number of maximum attempts that will be made to run a

Returns:

the max number of attempts per reduce task.

getNumReduceTasks

public int getNumReduceTasks()

Description copied from interface: JobContext

Get configured the number of reduce tasks for this job. Defaults to 1.

Returns:

the number of reduce tasks for this job.

getOutputFormatClass

public java.lang.Class<? extends OutputFormat<?,?>> getOutputFormatClass()
                                                                  throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the OutputFormat class for the job.

Returns:

the OutputFormat class for the job.

Throws:

java.lang.ClassNotFoundException

getOutputKeyClass

public java.lang.Class<?> getOutputKeyClass()

Description copied from interface: JobContext

Get the key class for the job output data.

Returns:

the key class for the job output data.

getOutputValueClass

public java.lang.Class<?> getOutputValueClass()

Description copied from interface: JobContext

Get the value class for job outputs.

Returns:

the value class for job outputs.

getPartitionerClass

public java.lang.Class<? extends Partitioner<?,?>> getPartitionerClass()
                                                                throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the Partitioner class for the job.

Returns:

the Partitioner class for the job.

Throws:

java.lang.ClassNotFoundException

getReducerClass

public java.lang.Class<? extends Reducer<?,?,?,?>> getReducerClass()
                                                            throws java.lang.ClassNotFoundException

Description copied from interface: JobContext

Get the Reducer class for the job.

Returns:

the Reducer class for the job.

Throws:

java.lang.ClassNotFoundException

getSortComparator

public org.apache.hadoop.io.RawComparator<?> getSortComparator()

Description copied from interface: JobContext

Get the RawComparator comparator used to compare keys.

Returns:

the RawComparator comparator used to compare keys.

getSymlink

public boolean getSymlink()

Description copied from interface: JobContext

This method checks to see if symlinks are to be create for the localized cache files in the current working directory

Returns:

true if symlinks are to be created- else return false

getWorkingDirectory

public org.apache.hadoop.fs.Path getWorkingDirectory()
                                              throws java.io.IOException

Description copied from interface: JobContext

Get the current working directory for the default file system.

Returns:

the directory name.

Throws:

java.io.IOException

progress

public void progress()

getValues

public java.lang.Iterable<VALUEIN> getValues()
                                      throws java.io.IOException,
                                             java.lang.InterruptedException

Description copied from interface: ReduceContext

Iterate through the values for the current key, reusing the same value object, which is stored in the context.

Returns:

the series of values associated with the current key. All of the objects returned directly and indirectly from this method are reused.

Throws:

java.io.IOException

java.lang.InterruptedException

nextKey

public boolean nextKey()
                throws java.io.IOException,
                       java.lang.InterruptedException

Description copied from interface: ReduceContext

Start processing next unique key.

Throws:

java.io.IOException

java.lang.InterruptedException

getProfileEnabled

public boolean getProfileEnabled()

Description copied from interface: JobContext

Get whether the task profiling is enabled.

Returns:

true if some tasks will be profiled

getProfileParams

public java.lang.String getProfileParams()

Returns:

the parameters to pass to the task child to configure profiling

getUser

public java.lang.String getUser()

Description copied from interface: JobContext

Get the reported username for this job.

Returns:

the username

getCredentials

public org.apache.hadoop.security.Credentials getCredentials()

Description copied from interface: JobContext

Get credentials for the job.

Returns:

credentials for the job