Package org.apache.hadoop.mapred

Interface MapRunnable<K1,V1,K2,V2>

All Superinterfaces:

JobConfigurable

All Known Implementing Classes:

MapRunner, MultithreadedMapRunner

@Public
@Stable
public interface MapRunnable<K1,V1,K2,V2>
extends JobConfigurable

Expert: Generic interface for Mappers.

Custom implementations of MapRunnable can exert greater control on map processing e.g. multi-threaded, asynchronous mappers etc.

See Also:

• Mapper

Method Summary

Modifier and Type	Method	Description
void	run(RecordReader<K1,V1> input, OutputCollector<K2,V2> output, Reporter reporter)	Start mapping input <key, value> pairs.

Methods inherited from interface org.apache.hadoop.mapred.JobConfigurable

configure

Method Details

run

void run(RecordReader<K1,V1> input,
 OutputCollector<K2,V2> output,
 Reporter reporter)
  throws IOException

Start mapping input <key, value> pairs.

Mapping of input records to output records is complete when this method returns.

Parameters:

input - the RecordReader to read the input records.

output - the OutputCollector to collect the outputrecords.

reporter - Reporter to report progress, status-updates etc.

Throws:

IOException