com.splout.db.hadoop
Class SumReducer

java.lang.Object
  com.datasalt.pangool.tuplemr.TupleReducer<com.datasalt.pangool.io.ITuple,org.apache.hadoop.io.NullWritable>
      com.splout.db.hadoop.SumReducer

All Implemented Interfaces:

java.io.Serializable

public class SumReducer
extends com.datasalt.pangool.tuplemr.TupleReducer<com.datasalt.pangool.io.ITuple,org.apache.hadoop.io.NullWritable>

Reusable TupleReducer that aggregates the counts of a certain field in the Tuple.

There are nicer implementations of this in the work-in-progress Pangool-flow project of Pangool but I decided not to depend on it until it has a first stable version.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.datasalt.pangool.tuplemr.TupleReducer

com.datasalt.pangool.tuplemr.TupleReducer.Collector, com.datasalt.pangool.tuplemr.TupleReducer.CombinerCollector, com.datasalt.pangool.tuplemr.TupleReducer.StaticCollector<OUTPUT_KEY,OUTPUT_VALUE,CONTEXT_OUTPUT_KEY,CONTEXT_OUTPUT_VALUE>, com.datasalt.pangool.tuplemr.TupleReducer.TupleMRContext

Constructor Summary

SumReducer(java.lang.String field)
Will (int) sum the field "field"

Method Summary

void	reduce(com.datasalt.pangool.io.ITuple group, java.lang.Iterable<com.datasalt.pangool.io.ITuple> tuples, com.datasalt.pangool.tuplemr.TupleReducer.TupleMRContext context, com.datasalt.pangool.tuplemr.TupleReducer.Collector collector)

Methods inherited from class com.datasalt.pangool.tuplemr.TupleReducer

cleanup, setup

Methods inherited from class java.lang.Object

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

Constructor Detail

SumReducer

public SumReducer(java.lang.String field)

Will (int) sum the field "field"

Method Detail

reduce

public void reduce(com.datasalt.pangool.io.ITuple group,
                   java.lang.Iterable<com.datasalt.pangool.io.ITuple> tuples,
                   com.datasalt.pangool.tuplemr.TupleReducer.TupleMRContext context,
                   com.datasalt.pangool.tuplemr.TupleReducer.Collector collector)
            throws java.io.IOException,
                   java.lang.InterruptedException,
                   com.datasalt.pangool.tuplemr.TupleMRException

Overrides:

reduce in class com.datasalt.pangool.tuplemr.TupleReducer<com.datasalt.pangool.io.ITuple,org.apache.hadoop.io.NullWritable>

Throws:

java.io.IOException

java.lang.InterruptedException

com.datasalt.pangool.tuplemr.TupleMRException