org.infinispan.partitionhandling.impl

Interface AvailabilityStrategyContext

All Known Implementing Classes:

ClusterCacheStatus

public interface AvailabilityStrategyContext

Contains information about the current state of the cache. Also allows AvailabilityStrategy to proceed with a rebalance, a membership update, or an availability mode change. Implementations should not use blocking calls.

Author:

Mircea Markus, Dan Berindei

Method Summary

Modifier and Type	Method and Description
ConsistentHash	calculateConflictHash(ConsistentHash preferredHash, Set<ConsistentHash> distinctHashes, List<Address> actualMembers)
AvailabilityMode	getAvailabilityMode()
String	getCacheName()
Map<Address,Float>	getCapacityFactors()
CacheTopology	getCurrentTopology()
List<Address>	getExpectedMembers() The members of the cache.
CacheJoinInfo	getJoinInfo()
CacheTopology	getStableTopology() Whenever a new cache topology without a pendingCH and with at least numOwners owners for each segment is installed, and the cache is AvailabilityMode.AVAILABLE, the current cache topology is marked as the stable topology.
void	queueConflictResolution(CacheTopology conflictTopology, Set<Address> preferredNodes) Initiates conflict resolution using the conflictTopology, which should have already been broadcast via this#updateTopologiesAfterMerge(CacheTopology, CacheTopology, AvailabilityMode)
void	queueRebalance(List<Address> newMembers) Queue (or start) a rebalance.
boolean	resolveConflictsOnMerge()
boolean	restartConflictResolution(List<Address> newMembers) If CR is in progress, then this method cancels the current CR and starts a new CR phase with an updated topology based upon newMembers and the previously queued CR topology
void	updateAvailabilityMode(List<Address> actualMembers, AvailabilityMode mode, boolean cancelRebalance) Enter a new availability mode.
void	updateCurrentTopology(List<Address> newMembers) Use the configured ConsistentHashFactory to create a new CH with the given members, but do not start a rebalance.
void	updateTopologiesAfterMerge(CacheTopology currentTopology, CacheTopology stableTopology, AvailabilityMode availabilityMode) Updates both the stable and the current topologies.

Method Detail

getCacheName

String getCacheName()

getJoinInfo

CacheJoinInfo getJoinInfo()

getCapacityFactors

Map<Address,Float> getCapacityFactors()

getCurrentTopology

CacheTopology getCurrentTopology()

Returns:

The current cache topology.

getStableTopology

CacheTopology getStableTopology()

Whenever a new cache topology without a pendingCH and with at least numOwners owners for each segment is installed, and the cache is AvailabilityMode.AVAILABLE, the current cache topology is marked as the stable topology. The same happens when a rebalance is scheduled to start, but it doesn't do anything because the current topology is already balanced.

Returns:

The last stable cache topology. May be null.

getAvailabilityMode

AvailabilityMode getAvailabilityMode()

Returns:

The current availability mode.

getExpectedMembers

List<Address> getExpectedMembers()

The members of the cache. Includes nodes which have tried to join the cache but are not yet part of the current CacheTopology. Does not include nodes which have left the cluster (either gracefully or abruptly) but are still in the current topology.

queueRebalance

void queueRebalance(List<Address> newMembers)

Queue (or start) a rebalance. Use the configured ConsistentHashFactory to create a new balanced consistent hash with the given members. If there is no rebalance in progress, start a rebalance right away. If there is a rebalance in progress, queue another rebalance. If there is a rebalance in the queue as well, it will be replaced with the new one. If newConsistentHash == null, remove any queued rebalance.

updateCurrentTopology

void updateCurrentTopology(List<Address> newMembers)

Use the configured ConsistentHashFactory to create a new CH with the given members, but do not start a rebalance. Members missing from the current topology are ignored.

updateAvailabilityMode

void updateAvailabilityMode(List<Address> actualMembers,
                            AvailabilityMode mode,
                            boolean cancelRebalance)

Enter a new availability mode.

updateTopologiesAfterMerge

void updateTopologiesAfterMerge(CacheTopology currentTopology,
                                CacheTopology stableTopology,
                                AvailabilityMode availabilityMode)

Updates both the stable and the current topologies. Does not install the current topology on the cache members.

resolveConflictsOnMerge

boolean resolveConflictsOnMerge()

Returns:

true if PartitionHandlingConfiguration.mergePolicy() != null

calculateConflictHash

ConsistentHash calculateConflictHash(ConsistentHash preferredHash,
                                     Set<ConsistentHash> distinctHashes,
                                     List<Address> actualMembers)

Parameters:

preferredHash - the base consistent hash

distinctHashes - a set of all hashes to be utilised as part of the conflict resolution hash

actualMembers - a set of all valid addresses

Returns:

the hash to be utilised as a pending CH during Phase.CONFLICT_RESOLUTION

queueConflictResolution

void queueConflictResolution(CacheTopology conflictTopology,
                             Set<Address> preferredNodes)

Initiates conflict resolution using the conflictTopology, which should have already been broadcast via this#updateTopologiesAfterMerge(CacheTopology, CacheTopology, AvailabilityMode)

Parameters:

conflictTopology - the topology to use during conflict resolution

preferredNodes - the addresses that belong to the preferred partition as determined by the AvailabilityStrategy

restartConflictResolution

boolean restartConflictResolution(List<Address> newMembers)

If CR is in progress, then this method cancels the current CR and starts a new CR phase with an updated topology based upon newMembers and the previously queued CR topology

Parameters:

newMembers - the latest members of the current view

Returns:

true if conflict resolution was restarted due to the newMembers