ml.shifu.guagua.master

Class AbstractMasterComputable<MASTER_RESULT extends Bytable,WORKER_RESULT extends Bytable>

java.lang.Object

ml.shifu.guagua.master.AbstractMasterComputable<MASTER_RESULT,WORKER_RESULT>

All Implemented Interfaces:

MasterComputable<MASTER_RESULT,WORKER_RESULT>

public abstract class AbstractMasterComputable<MASTER_RESULT extends Bytable,WORKER_RESULT extends Bytable>
extends Object
implements MasterComputable<MASTER_RESULT,WORKER_RESULT>

AbstractMasterComputable is a abstract MasterComputable implementation to add init(MasterContext) for master. Real computation logic is derived into doCompute(MasterContext).

Author:

Zhang David (pengzhang@paypal.com)

Field Summary

Fields

Modifier and Type	Field and Description
protected AtomicBoolean	isInitialized

Constructor Summary

Constructors

Constructor and Description
AbstractMasterComputable()

Method Summary

Modifier and Type	Method and Description
MASTER_RESULT	compute(MasterContext<MASTER_RESULT,WORKER_RESULT> context) Master computation for each iteration.
abstract MASTER_RESULT	doCompute(MasterContext<MASTER_RESULT,WORKER_RESULT> context) Real computable logic excludes init part.
abstract void	init(MasterContext<MASTER_RESULT,WORKER_RESULT> context) Initialization logic.

Methods inherited from class java.lang.Object

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

Field Detail

isInitialized

protected AtomicBoolean isInitialized

Constructor Detail

AbstractMasterComputable

public AbstractMasterComputable()

Method Detail

compute

public MASTER_RESULT compute(MasterContext<MASTER_RESULT,WORKER_RESULT> context)

Description copied from interface: MasterComputable

Master computation for each iteration.

Specified by:

compute in interface MasterComputable<MASTER_RESULT extends Bytable,WORKER_RESULT extends Bytable>

Parameters:

context - the master context instance which includes worker results and other useful parameters.

Returns:

the master result of each iteration.

init

public abstract void init(MasterContext<MASTER_RESULT,WORKER_RESULT> context)

Initialization logic. This is used to initialize some useful fields like config parameters. And another important feature can be done here: If state in MasterComputable, for fail-over, the state should also be recoverd. To do that, like this in this method:

 if (!context.isFirstIteration) { // not first iteration means we need recover state
     lastMasterResult = context.getMasterResult();
     if ( lasterMasterResult != null ) {
         this.weights = lastMasterResult.getWeights()
     } else {
         this.weights = initWeights();
     }
 }
 

doCompute

public abstract MASTER_RESULT doCompute(MasterContext<MASTER_RESULT,WORKER_RESULT> context)

Real computable logic excludes init part.