Package org.apache.hadoop.mapred

A system for scalable, fault-tolerant, distributed computation over large data collections.

See:
          Description

Interface Summary
InputFormat An input data format.
JobConfigurable That what may be configured.
MapOutputLocation.Pingable An interface for callbacks when an method makes some progress.
Mapper Maps input key/value pairs to a set of intermediate key/value pairs.
MapRunnable Expert: Permits greater control of map processing.
OutputCollector Passed to Mapper and Reducer implementations to collect output data.
OutputFormat An output data format.
Partitioner Partitions the key space.
RecordReader Reads key/value pairs from an input file FileSplit.
RecordWriter Writes key/value pairs to an output file.
Reducer Reduces a set of intermediate values which share a key to a smaller set of values.
Reporter Passed to application code to permit alteration of status.
RunningJob Includes details on a running MapReduce job.
 

Class Summary
ClusterStatus Summarizes the size and current state of the cluster.
FileSplit A section of an input file.
InputFormatBase A base class for InputFormat.
JobClient JobClient interacts with the JobTracker network interface.
JobConf A map/reduce job configuration.
JobTracker JobTracker is the central location for submitting and tracking MR jobs in a network environment.
MapFileOutputFormat An OutputFormat that writes MapFiles.
MapReduceBase Base class for Mapper and Reducer implementations.
MapRunner Default MapRunnable implementation.
OutputFormatBase A base class for OutputFormat.
SequenceFileInputFormat An InputFormat for SequenceFiles.
SequenceFileOutputFormat An OutputFormat that writes SequenceFiles.
SequenceFileRecordReader An RecordReader for SequenceFiles.
StatusHttpServer Create a Jetty embedded server to answer http requests.
TaskReport A report on the state of a task.
TaskTracker TaskTracker is a process that starts and tracks MR Tasks in a networked environment.
TaskTracker.Child The main() for child processes.
TextInputFormat An InputFormat for plain text files.
TextOutputFormat An OutputFormat that writes plain text files.
 

Package org.apache.hadoop.mapred Description

A system for scalable, fault-tolerant, distributed computation over large data collections.

Applications implement Mapper and Reducer interfaces. These are submitted as a JobConf and are applied to data stored in a FileSystem.

See Google's original Map/Reduce paper for background information.



Copyright © 2006 The Apache Software Foundation