Package org.apache.hadoop.mapreduce

Interface Summary

Counter	A named counter that tracks the progress of a map/reduce job.
CounterGroup	A group of Counters that logically belong together.
JobContext	A read-only view of the job that is provided to the tasks while they are running.
MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	The context that is given to the Mapper.
MRConfig	Place holder for cluster level configuration keys.
MRJobConfig
ReduceContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	The context passed to the Reducer.
ReduceContext.ValueIterator<VALUEIN>	Iterator to iterate over values for a given group of records.
TaskAttemptContext	The context for task attempts.
TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	A context object that allows input and output from the task.

Class Summary

Cluster	Provides a way to access information about the map/reduce cluster.
ClusterMetrics	Status information on the current state of the Map-Reduce cluster.
ContextFactory	A factory to allow applications to deal with inconsistencies between MapReduce Context Objects API between hadoop-0.20 and later versions.
Counters	Counters holds per job/task counters, defined either by the Map-Reduce framework or applications.
ID	A general identifier, which internally stores the id as an integer.
InputFormat<K,V>	InputFormat describes the input-specification for a Map-Reduce job.
InputSplit	InputSplit represents the data to be processed by an individual Mapper.
Job	The job submitter's view of the Job.
JobID	JobID represents the immutable and unique identifier for the job.
JobStatus	Describes the current status of a job.
JobSubmissionFiles	A utility to manage job submission files.
Mapper<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	Maps input key/value pairs to a set of intermediate key/value pairs.
MarkableIterator<VALUE>	MarkableIterator is a wrapper iterator class that implements the MarkableIteratorInterface.
OutputCommitter	OutputCommitter describes the commit of task output for a Map-Reduce job.
OutputFormat<K,V>	OutputFormat describes the output-specification for a Map-Reduce job.
Partitioner<KEY,VALUE>	Partitions the key space.
QueueAclsInfo	Class to encapsulate Queue ACLs for a particular user.
QueueInfo	Class that contains the information regarding the Job Queues which are maintained by the Hadoop Map/Reduce framework.
RecordReader<KEYIN,VALUEIN>	The record reader breaks the data into key/value pairs for input to the Mapper.
RecordWriter<K,V>	RecordWriter writes the output <key, value> pairs to an output file.
Reducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>	Reduces a set of intermediate values which share a key to a smaller set of values.
StatusReporter
TaskAttemptID	TaskAttemptID represents the immutable and unique identifier for a task attempt.
TaskCompletionEvent	This is used to track task completion events on job tracker.
TaskID	TaskID represents the immutable and unique identifier for a Map or Reduce Task.
TaskReport	A report on the state of a task.
TaskTrackerInfo	Information about TaskTracker.

Enum Summary

Cluster.JobTrackerStatus
FileSystemCounter
Job.JobState
Job.TaskStatusFilter
JobACL	Job related ACLs
JobCounter
JobPriority	Used to describe the priority of the running job.
JobStatus.State	Current state of the job
QueueState	Enum representing queue state
TaskCompletionEvent.Status
TaskCounter
TaskType	Enum for map, reduce, job-setup, job-cleanup, task-cleanup task types.