com.hazelcast.cardinality.impl

Class CardinalityEstimatorService

java.lang.Object

com.hazelcast.cardinality.impl.CardinalityEstimatorService

All Implemented Interfaces:

ManagedService, MigrationAwareService, QuorumAwareService, RemoteService, SplitBrainHandlerService

public class CardinalityEstimatorService
extends Object
implements ManagedService, RemoteService, MigrationAwareService, QuorumAwareService, SplitBrainHandlerService

Field Summary

Fields

Modifier and Type	Field and Description
static String	SERVICE_NAME

Constructor Summary

Constructors

Constructor and Description
CardinalityEstimatorService()

Method Summary

Modifier and Type	Method and Description
void	addCardinalityEstimator(String name, CardinalityEstimatorContainer container)
void	beforeMigration(PartitionMigrationEvent event) Called before migration process starts, on both source and destination members.
void	commitMigration(PartitionMigrationEvent event) Commits the migration process for this service, on both source and destination members.
CardinalityEstimatorProxy	createDistributedObject(String objectName) Creates a distributed object.
void	destroyDistributedObject(String objectName) Destroys a distributed object.
CardinalityEstimatorContainer	getCardinalityEstimatorContainer(String name)
String	getQuorumName(String name) Gets the name of the quorum associated with specified operation name.
void	init(NodeEngine nodeEngine, Properties properties) Initializes this service.
Runnable	prepareMergeRunnable() When the two separate clusters merge (resolve a split-brain), this method is called to return a Runnable, that will merge the clusters.
Operation	prepareReplicationOperation(PartitionReplicationEvent event) Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.
void	reset() Resets this service back to its initial state.
void	rollbackMigration(PartitionMigrationEvent event) Rollback the migration process for this service, on both source and destination members.
void	shutdown(boolean terminate) Shuts down this service.

Methods inherited from class java.lang.Object

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

Field Detail

SERVICE_NAME

public static final String SERVICE_NAME

See Also:

Constant Field Values

Constructor Detail

CardinalityEstimatorService

public CardinalityEstimatorService()

Method Detail

addCardinalityEstimator

public void addCardinalityEstimator(String name,
                                    CardinalityEstimatorContainer container)

getCardinalityEstimatorContainer

public CardinalityEstimatorContainer getCardinalityEstimatorContainer(String name)

init

public void init(NodeEngine nodeEngine,
                 Properties properties)

Description copied from interface: ManagedService

Initializes this service.

Specified by:

init in interface ManagedService

Parameters:

nodeEngine - the NodeEngine that this service belongs to

properties - the Properties (can be used to pass settings to the service)

reset

public void reset()

Description copied from interface: ManagedService

Resets this service back to its initial state.

TODO: what is the purpose of reset

Specified by:

reset in interface ManagedService

shutdown

public void shutdown(boolean terminate)

Description copied from interface: ManagedService

Shuts down this service.

TODO: what is the purpose of the terminate variable

Specified by:

shutdown in interface ManagedService

Parameters:

terminate - true to shut down this service

createDistributedObject

public CardinalityEstimatorProxy createDistributedObject(String objectName)

Description copied from interface: RemoteService

Creates a distributed object.

Specified by:

createDistributedObject in interface RemoteService

Parameters:

objectName - the name for the created distributed object

Returns:

the created distributed object

destroyDistributedObject

public void destroyDistributedObject(String objectName)

Description copied from interface: RemoteService

Destroys a distributed object.

Specified by:

destroyDistributedObject in interface RemoteService

Parameters:

objectName - the name of the distributed object to destroy

beforeMigration

public void beforeMigration(PartitionMigrationEvent event)

Description copied from interface: MigrationAwareService

Called before migration process starts, on both source and destination members.

Service can take actions required before migration. Migration process will block until this method returns. If this method fails by throwing an exception, migration process for specific partition will fail and will be rolled back.

Specified by:

beforeMigration in interface MigrationAwareService

Parameters:

event - migration event

prepareReplicationOperation

public Operation prepareReplicationOperation(PartitionReplicationEvent event)

Description copied from interface: MigrationAwareService

Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.

This method will be called on source member whenever partitioning system requires to copy/replicate a partition replica. Returned operation will be executed on destination member. If operation fails by throwing exception, migration process will fail and will be rolled back.

Returning null is allowed and means service does not have anything to replicate.

Specified by:

prepareReplicationOperation in interface MigrationAwareService

Parameters:

event - replication

Returns:

replication operation or null if nothing will be replicated

commitMigration

public void commitMigration(PartitionMigrationEvent event)

Description copied from interface: MigrationAwareService

Commits the migration process for this service, on both source and destination members. This method will be called after all replication operations are executed successfully on destination and master member receives success response from all participants.

Commit is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.

Specified by:

commitMigration in interface MigrationAwareService

Parameters:

event - migration event

rollbackMigration

public void rollbackMigration(PartitionMigrationEvent event)

Description copied from interface: MigrationAwareService

Rollback the migration process for this service, on both source and destination members. This method will be called when migration process fails at any moment. Reasons for failure may be an exception thrown on any migration step or failure(s) of any of the migration participants; either master or source or destination.

Rollback is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.

Specified by:

rollbackMigration in interface MigrationAwareService

Parameters:

event - migration event

getQuorumName

public String getQuorumName(String name)

Description copied from interface: QuorumAwareService

Gets the name of the quorum associated with specified operation name.

Specified by:

getQuorumName in interface QuorumAwareService

Parameters:

name - the operation name for which the quorum name is retured

Returns:

name of the associated quorum, null if there is no associated quorum

prepareMergeRunnable

public Runnable prepareMergeRunnable()

Description copied from interface: SplitBrainHandlerService

When the two separate clusters merge (resolve a split-brain), this method is called to return a Runnable, that will merge the clusters.

Specified by:

prepareMergeRunnable in interface SplitBrainHandlerService

Returns:

a Runnable that will merge the clusters