org.apache.bookkeeper.client

Class RackawareEnsemblePlacementPolicy

java.lang.Object

org.apache.bookkeeper.client.RackawareEnsemblePlacementPolicy

All Implemented Interfaces:

EnsemblePlacementPolicy

public class RackawareEnsemblePlacementPolicy
extends Object
implements EnsemblePlacementPolicy

Simple rackware ensemble placement policy. Make most of the class and methods as protected, so it could be extended to implement other algorithms.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	RackawareEnsemblePlacementPolicy.BookieNode
protected static interface	RackawareEnsemblePlacementPolicy.Ensemble Ensemble used to hold the result of an ensemble selected for placement.
protected static class	RackawareEnsemblePlacementPolicy.EnsembleForReplacement
protected static interface	RackawareEnsemblePlacementPolicy.Predicate Predicate used when choosing an ensemble.
protected static class	RackawareEnsemblePlacementPolicy.RRRackCoverageEnsemble A predicate checking the rack coverage for write quorum in RoundRobinDistributionSchedule, which ensures that a write quorum should be covered by at least two racks.
protected static class	RackawareEnsemblePlacementPolicy.TruePredicate

Field Summary

Fields

Modifier and Type	Field and Description
static String	REPP_DNS_RESOLVER_CLASS

Constructor Summary

Constructors

Constructor and Description
RackawareEnsemblePlacementPolicy()

Method Summary

Methods

Modifier and Type	Method and Description
protected String	getRemoteRack(RackawareEnsemblePlacementPolicy.BookieNode node)
EnsemblePlacementPolicy	initialize(org.apache.commons.configuration.Configuration conf) Initialize the policy.
ArrayList<org.apache.bookkeeper.net.BookieSocketAddress>	newEnsemble(int ensembleSize, int writeQuorumSize, Set<org.apache.bookkeeper.net.BookieSocketAddress> excludeBookies) Choose numBookies bookies for ensemble.
Set<org.apache.bookkeeper.net.BookieSocketAddress>	onClusterChanged(Set<org.apache.bookkeeper.net.BookieSocketAddress> writableBookies, Set<org.apache.bookkeeper.net.BookieSocketAddress> readOnlyBookies) A consistent view of the cluster (what bookies are available as writable, what bookies are available as readonly) is updated when any changes happen in the cluster.
org.apache.bookkeeper.net.BookieSocketAddress	replaceBookie(org.apache.bookkeeper.net.BookieSocketAddress bookieToReplace, Set<org.apache.bookkeeper.net.BookieSocketAddress> excludeBookies) Choose a new bookie to replace bookieToReplace.
protected RackawareEnsemblePlacementPolicy.BookieNode	selectFromRack(String networkLoc, Set<org.apache.bookkeeper.net.Node> excludeBookies, RackawareEnsemblePlacementPolicy.Predicate predicate, RackawareEnsemblePlacementPolicy.Ensemble ensemble)
protected List<RackawareEnsemblePlacementPolicy.BookieNode>	selectRandom(int numBookies, Set<org.apache.bookkeeper.net.Node> excludeBookies, RackawareEnsemblePlacementPolicy.Ensemble ensemble) Choose a random node from whole cluster.
protected RackawareEnsemblePlacementPolicy.BookieNode	selectRandomFromRack(String netPath, Set<org.apache.bookkeeper.net.Node> excludeBookies, RackawareEnsemblePlacementPolicy.Predicate predicate, RackawareEnsemblePlacementPolicy.Ensemble ensemble) Choose random node under a given network path.
void	uninitalize() Uninitialize the policy

Methods inherited from class java.lang.Object

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

Field Detail

REPP_DNS_RESOLVER_CLASS

public static final String REPP_DNS_RESOLVER_CLASS

See Also:

Constant Field Values

Constructor Detail

RackawareEnsemblePlacementPolicy

public RackawareEnsemblePlacementPolicy()

Method Detail

initialize

public EnsemblePlacementPolicy initialize(org.apache.commons.configuration.Configuration conf)

Description copied from interface: EnsemblePlacementPolicy

Initialize the policy.

Specified by:

initialize in interface EnsemblePlacementPolicy

Parameters:

conf - client configuration.

Returns:

initialized ensemble placement policy

uninitalize

public void uninitalize()

Description copied from interface: EnsemblePlacementPolicy

Uninitialize the policy

Specified by:

uninitalize in interface EnsemblePlacementPolicy

onClusterChanged

public Set<org.apache.bookkeeper.net.BookieSocketAddress> onClusterChanged(Set<org.apache.bookkeeper.net.BookieSocketAddress> writableBookies,
                                                                  Set<org.apache.bookkeeper.net.BookieSocketAddress> readOnlyBookies)

Description copied from interface: EnsemblePlacementPolicy

A consistent view of the cluster (what bookies are available as writable, what bookies are available as readonly) is updated when any changes happen in the cluster.

Specified by:

onClusterChanged in interface EnsemblePlacementPolicy

Parameters:

writableBookies - All the bookies in the cluster available for write/read.

readOnlyBookies - All the bookies in the cluster available for readonly.

Returns:

the dead bookies during this cluster change.

newEnsemble

public ArrayList<org.apache.bookkeeper.net.BookieSocketAddress> newEnsemble(int ensembleSize,
                                                                   int writeQuorumSize,
                                                                   Set<org.apache.bookkeeper.net.BookieSocketAddress> excludeBookies)
                                                                     throws BKException.BKNotEnoughBookiesException

Description copied from interface: EnsemblePlacementPolicy

Choose numBookies bookies for ensemble. If the count is more than the number of available nodes, BKException.BKNotEnoughBookiesException is thrown.

Specified by:

newEnsemble in interface EnsemblePlacementPolicy

Parameters:

ensembleSize - Ensemble Size

writeQuorumSize - Write Quorum Size

excludeBookies - Bookies that should not be considered as targets.

Returns:

list of bookies chosen as targets.

Throws:

BKException.BKNotEnoughBookiesException - if not enough bookies available.

replaceBookie

public org.apache.bookkeeper.net.BookieSocketAddress replaceBookie(org.apache.bookkeeper.net.BookieSocketAddress bookieToReplace,
                                                          Set<org.apache.bookkeeper.net.BookieSocketAddress> excludeBookies)
                                                            throws BKException.BKNotEnoughBookiesException

Description copied from interface: EnsemblePlacementPolicy

Choose a new bookie to replace bookieToReplace. If no bookie available in the cluster, BKException.BKNotEnoughBookiesException is thrown.

Specified by:

replaceBookie in interface EnsemblePlacementPolicy

Parameters:

bookieToReplace - bookie to replace

excludeBookies - bookies that should not be considered as candidate.

Returns:

the bookie chosen as target.

Throws:

BKException.BKNotEnoughBookiesException

selectFromRack

protected RackawareEnsemblePlacementPolicy.BookieNode selectFromRack(String networkLoc,
                                                         Set<org.apache.bookkeeper.net.Node> excludeBookies,
                                                         RackawareEnsemblePlacementPolicy.Predicate predicate,
                                                         RackawareEnsemblePlacementPolicy.Ensemble ensemble)
                                                              throws BKException.BKNotEnoughBookiesException

Throws:

BKException.BKNotEnoughBookiesException

getRemoteRack

protected String getRemoteRack(RackawareEnsemblePlacementPolicy.BookieNode node)

selectRandomFromRack

protected RackawareEnsemblePlacementPolicy.BookieNode selectRandomFromRack(String netPath,
                                                               Set<org.apache.bookkeeper.net.Node> excludeBookies,
                                                               RackawareEnsemblePlacementPolicy.Predicate predicate,
                                                               RackawareEnsemblePlacementPolicy.Ensemble ensemble)
                                                                    throws BKException.BKNotEnoughBookiesException

Choose random node under a given network path.

Parameters:

netPath - network path

excludeBookies - exclude bookies

predicate - predicate to check whether the target is a good target.

ensemble - ensemble structure

Returns:

chosen bookie.

Throws:

BKException.BKNotEnoughBookiesException

selectRandom

protected List<RackawareEnsemblePlacementPolicy.BookieNode> selectRandom(int numBookies,
                                                             Set<org.apache.bookkeeper.net.Node> excludeBookies,
                                                             RackawareEnsemblePlacementPolicy.Ensemble ensemble)
                                                                  throws BKException.BKNotEnoughBookiesException

Choose a random node from whole cluster.

Parameters:

numBookies - number bookies to choose

excludeBookies - bookies set to exclude.

ensemble - ensemble to hold the bookie chosen.

Returns:

the bookie node chosen.

Throws:

BKException.BKNotEnoughBookiesException