org.apache.giraph.examples.scc

Class SccPhaseMasterCompute

java.lang.Object

org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable

org.apache.giraph.master.MasterCompute

org.apache.giraph.master.DefaultMasterCompute

org.apache.giraph.examples.scc.SccPhaseMasterCompute

All Implemented Interfaces:

AggregatorUsage, GiraphConfigurationSettable, ImmutableClassesGiraphConfigurable, MasterAggregatorUsage, MasterGlobalCommUsage, MasterGlobalCommUsageAggregators, org.apache.hadoop.io.Writable

public class SccPhaseMasterCompute
extends DefaultMasterCompute

This master compute keeps track of what phase is being currently executed by the Strongly Connected Components computation. The phases comprehend the following: 1 - Transpose (comprehends 2 supersteps, one to propagate parent vertices ids and another one to store them by their respective children) 2 - Trimming (this phase can happen multiple times) 3 - Forward Traversal 4 - Backward Traversal

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SccPhaseMasterCompute.Phases Enumerates the possible phases of the algorithm.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONVERGED Flags whether a vertex converged in the Backward Traversal phase
static String	NEW_MAXIMUM Flags whether a new maximum was found in the Forward Traversal phase
static String	PHASE Aggregator that stores the current phase

Constructor Summary

Constructors

Constructor and Description
SccPhaseMasterCompute()

Method Summary

Modifier and Type	Method and Description
void	compute() Must be defined by user to specify what the master has to do.
static SccPhaseMasterCompute.Phases	getPhase(org.apache.hadoop.io.IntWritable phaseInt) Helper function to convert from internal aggregated value to a Phases enumerator.
void	initialize() Initialize the MasterCompute class, this is the place to register aggregators.

Methods inherited from class org.apache.giraph.master.DefaultMasterCompute

readFields, write

Methods inherited from class org.apache.giraph.master.MasterCompute

broadcast, getAggregatedValue, getComputation, getContext, getMessageCombiner, getReduced, getSuperstep, getTotalNumEdges, getTotalNumVertices, getWorkerInfoList, haltComputation, isHalted, logToCommandLine, registerAggregator, registerPersistentAggregator, registerReducer, registerReducer, setAggregatedValue, setComputation, setGraphState, setIncomingMessage, setMasterService, setMessageCombiner, setOutgoingMessage, setOutgoingMessageClasses, setSuperstepClasses

Methods inherited from class org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable

getConf, setConf

Methods inherited from class java.lang.Object

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

Field Detail

PHASE

public static final String PHASE

Aggregator that stores the current phase

See Also:

Constant Field Values

NEW_MAXIMUM

public static final String NEW_MAXIMUM

Flags whether a new maximum was found in the Forward Traversal phase

See Also:

Constant Field Values

CONVERGED

public static final String CONVERGED

Flags whether a vertex converged in the Backward Traversal phase

See Also:

Constant Field Values

Constructor Detail

SccPhaseMasterCompute

public SccPhaseMasterCompute()

Method Detail

initialize

public void initialize()
                throws InstantiationException,
                       IllegalAccessException

Description copied from class: MasterCompute

Initialize the MasterCompute class, this is the place to register aggregators.

Overrides:

initialize in class DefaultMasterCompute

Throws:

InstantiationException

IllegalAccessException

compute

public void compute()

Description copied from class: MasterCompute

Must be defined by user to specify what the master has to do.

Overrides:

compute in class DefaultMasterCompute

getPhase

public static SccPhaseMasterCompute.Phases getPhase(org.apache.hadoop.io.IntWritable phaseInt)

Helper function to convert from internal aggregated value to a Phases enumerator.

Parameters:

phaseInt - An integer that matches a position in the Phases enumerator.

Returns:

A Phases' item for the given position.