RackawareEnsemblePlacementPolicy (bookkeeper 4.4.0-SNAPSHOT API)

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

Fields
Modifier and Type	Field and Description
`static String`	`REPP_DNS_RESOLVER_CLASS`

Constructor Summary

Constructors
Constructor and Description

RackawareEnsemblePlacementPolicy()

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

Class RackawareEnsemblePlacementPolicy

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

REPP_DNS_RESOLVER_CLASS

Constructor Detail

RackawareEnsemblePlacementPolicy

Method Detail

initialize

uninitalize

onClusterChanged

newEnsemble

replaceBookie

selectFromRack

getRemoteRack

selectRandomFromRack

selectRandom