cgl.imr.base
Interface ReduceTask


public interface ReduceTask

This interface encapsulates the methods that need to be supported by a user defined Reduce task.


Method Summary
 void close()
          Any cleanup goes here.
 void configure(JobConf jobConf, ReducerConf reducerConf)
          Use to configure a Reduce task for static data/or other configurations.
 void reduce(ReduceOutputCollector collector, Key key, List<Value> values)
          Perform the reduce operation for a given MapReduce computation.
 

Method Detail

close

void close()
           throws TwisterException
Any cleanup goes here.

Throws:
TwisterException

configure

void configure(JobConf jobConf,
               ReducerConf reducerConf)
               throws TwisterException
Use to configure a Reduce task for static data/or other configurations.

Parameters:
jobConf - - Job configuration object.
reducerConf - - Configurations specific to this Reduce task.
Throws:
TwisterException

reduce

void reduce(ReduceOutputCollector collector,
            Key key,
            List<Value> values)
            throws TwisterException
Perform the reduce operation for a given MapReduce computation.

Parameters:
collector - - Collector for the Reduce outputs
key - - Key associated with the list of Values passed to the Reduce function. The framework handles the grouping of different Keys sent from different Map tasks.
values - - List of values returned form Map tasks.
Throws:
TwisterException


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