org.apache.hadoop.mapred
Interface ShuffleConsumerPlugin

All Known Implementing Classes:
ReduceTask.ReduceCopier

@InterfaceAudience.LimitedPrivate(value="MapReduce")
@InterfaceStability.Unstable
public interface ShuffleConsumerPlugin


Nested Class Summary
static class ShuffleConsumerPlugin.Context
           
 
Method Summary
 void close()
          close and clean any resource associated with this object.
 RawKeyValueIterator createKVIterator()
          To create a key-value iterator to read the merged output.
 boolean fetchOutputs()
          To fetch the map outputs.
 java.lang.Throwable getMergeThrowable()
          To get any exception from merge.
 void init(ShuffleConsumerPlugin.Context context)
          To initialize the reduce copier plugin.
 

Method Detail

init

void init(ShuffleConsumerPlugin.Context context)
          throws java.lang.ClassNotFoundException,
                 java.io.IOException
To initialize the reduce copier plugin.

Parameters:
context - reduce copier context.
Throws:
java.lang.ClassNotFoundException
java.io.IOException

fetchOutputs

boolean fetchOutputs()
                     throws java.io.IOException
To fetch the map outputs.

Returns:
true if the fetch was successful; false otherwise.
Throws:
java.io.IOException

createKVIterator

RawKeyValueIterator createKVIterator()
                                     throws java.io.IOException
To create a key-value iterator to read the merged output.

Returns:
an iterator for merged key-value pairs.
Throws:
java.io.IOException

close

void close()
close and clean any resource associated with this object.


getMergeThrowable

java.lang.Throwable getMergeThrowable()
To get any exception from merge.



Copyright © 2009 The Apache Software Foundation