org.apache.giraph.block_app.framework.piece.global_comm.internal

Class ReducersForPieceHandler.GlobalReduceHandle<S,R extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.giraph.block_app.framework.piece.global_comm.internal.ReducersForPieceHandler.ReduceHandleImpl<S,R>

org.apache.giraph.block_app.framework.piece.global_comm.internal.ReducersForPieceHandler.GlobalReduceHandle<S,R>

Type Parameters:

S - Single value type

R - Reduced value type

All Implemented Interfaces:

VertexSenderObserver, ReducerHandle<S,R>

Enclosing class:

ReducersForPieceHandler

public class ReducersForPieceHandler.GlobalReduceHandle<S,R extends org.apache.hadoop.io.Writable>
extends ReducersForPieceHandler.ReduceHandleImpl<S,R>

Global Reduce Handle is implementation of ReducerHandle, that will keep only one value for each worker, and each call to reduce will have to obtain a global lock, and incur synchronization costs. Use only when objects are so large, that having many copies cannot fit into memory.

Field Summary

Fields inherited from class org.apache.giraph.block_app.framework.piece.global_comm.internal.ReducersForPieceHandler.ReduceHandleImpl

reduceOp

Constructor Summary

Constructors

Constructor and Description
GlobalReduceHandle(ReduceOperation<S,R> reduceOp)

Method Summary

Modifier and Type	Method and Description
void	reduce(S valueToReduce) Reduce single value
void	vertexSenderWorkerPostprocess(WorkerReduceUsage usage)
void	vertexSenderWorkerPreprocess(WorkerReduceUsage usage)

Methods inherited from class org.apache.giraph.block_app.framework.piece.global_comm.internal.ReducersForPieceHandler.ReduceHandleImpl

broadcastValue, getName, getReducedValue

Methods inherited from class java.lang.Object

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

Constructor Detail

GlobalReduceHandle

public GlobalReduceHandle(ReduceOperation<S,R> reduceOp)

Method Detail

vertexSenderWorkerPreprocess

public void vertexSenderWorkerPreprocess(WorkerReduceUsage usage)

reduce

public void reduce(S valueToReduce)

Description copied from interface: ReducerHandle

Reduce single value

vertexSenderWorkerPostprocess

public void vertexSenderWorkerPostprocess(WorkerReduceUsage usage)