com.hazelcast.collection.impl.queue

Class QueueService

java.lang.Object

com.hazelcast.collection.impl.queue.QueueService

All Implemented Interfaces:

EventPublishingService<QueueEvent,ItemListener>, ManagedService, MigrationAwareService, QuorumAwareService, RemoteService, SplitBrainHandlerService, StatisticsAwareService<LocalQueueStats>, TransactionalService

public class QueueService
extends Object
implements ManagedService, MigrationAwareService, TransactionalService, RemoteService, EventPublishingService<QueueEvent,ItemListener>, StatisticsAwareService<LocalQueueStats>, QuorumAwareService, SplitBrainHandlerService

Provides important services via methods for the the Queue such as QueueEvictionProcessor

Field Summary

Fields

Modifier and Type	Field and Description
static String	SERVICE_NAME

Constructor Summary

Constructors

Constructor and Description
QueueService(NodeEngine nodeEngine)

Method Summary

Modifier and Type	Method and Description
void	addContainer(String name, QueueContainer container)
String	addItemListener(String name, ItemListener listener, boolean includeValue, boolean isLocal)
void	beforeMigration(PartitionMigrationEvent partitionMigrationEvent) Called before migration process starts, on both source and destination members.
void	cancelEviction(String name)
void	commitMigration(PartitionMigrationEvent event) Commits the migration process for this service, on both source and destination members.
boolean	containsQueue(String name)
QueueProxyImpl	createDistributedObject(String objectId) Creates a distributed object.
LocalQueueStats	createLocalQueueStats(String name) Returns the local queue statistics for the queue with the given name.
LocalQueueStats	createLocalQueueStats(String name, int partitionId) Returns the local queue statistics for the given name and partition ID.
TransactionalQueueProxy	createTransactionalObject(String name, Transaction transaction)
void	destroyDistributedObject(String name) Destroys a distributed object.
void	dispatchEvent(QueueEvent event, ItemListener listener) Notifies the service of a published event.
LocalQueueStatsImpl	getLocalQueueStatsImpl(String name)
NodeEngine	getNodeEngine()
QueueContainer	getOrCreateContainer(String name, boolean fromBackup)
String	getQuorumName(String name) Gets the name of the quorum associated with specified operation name.
Map<String,LocalQueueStats>	getStats() Return the service statistics for the local instance.
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.
boolean	removeItemListener(String name, String registrationId)
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	rollbackTransaction(String transactionId)
void	scheduleEviction(String name, long delay)
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

QueueService

public QueueService(NodeEngine nodeEngine)

Method Detail

scheduleEviction

public void scheduleEviction(String name,
                             long delay)

cancelEviction

public void cancelEviction(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

getOrCreateContainer

public QueueContainer getOrCreateContainer(String name,
                                           boolean fromBackup)

addContainer

public void addContainer(String name,
                         QueueContainer container)

containsQueue

public boolean containsQueue(String name)

beforeMigration

public void beforeMigration(PartitionMigrationEvent partitionMigrationEvent)

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:

partitionMigrationEvent - 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

dispatchEvent

public void dispatchEvent(QueueEvent event,
                          ItemListener listener)

Description copied from interface: EventPublishingService

Notifies the service of a published event.

Specified by:

dispatchEvent in interface EventPublishingService<QueueEvent,ItemListener>

Parameters:

event - the published event

listener - the listener registered for this event

createDistributedObject

public QueueProxyImpl createDistributedObject(String objectId)

Description copied from interface: RemoteService

Creates a distributed object.

Specified by:

createDistributedObject in interface RemoteService

Parameters:

objectId - the name for the created distributed object

Returns:

the created distributed object

destroyDistributedObject

public void destroyDistributedObject(String name)

Description copied from interface: RemoteService

Destroys a distributed object.

Specified by:

destroyDistributedObject in interface RemoteService

Parameters:

name - the name of the distributed object to destroy

addItemListener

public String addItemListener(String name,
                              ItemListener listener,
                              boolean includeValue,
                              boolean isLocal)

removeItemListener

public boolean removeItemListener(String name,
                                  String registrationId)

getNodeEngine

public NodeEngine getNodeEngine()

createLocalQueueStats

public LocalQueueStats createLocalQueueStats(String name,
                                             int partitionId)

Returns the local queue statistics for the given name and partition ID. If this node is the owner for the partition, returned stats contain LocalQueueStats.getOwnedItemCount(), otherwise it contains LocalQueueStats.getBackupItemCount().

Parameters:

name - the name of the queue for which the statistics are returned

partitionId - the partition ID for which the statistics are returned

Returns:

the statistics

createLocalQueueStats

public LocalQueueStats createLocalQueueStats(String name)

Returns the local queue statistics for the queue with the given name. If this node is the owner of the queue, returned stats contain LocalQueueStats.getOwnedItemCount(), otherwise it contains LocalQueueStats.getBackupItemCount().

Parameters:

name - the name of the queue for which the statistics are returned

Returns:

the statistics

getLocalQueueStatsImpl

public LocalQueueStatsImpl getLocalQueueStatsImpl(String name)

createTransactionalObject

public TransactionalQueueProxy createTransactionalObject(String name,
                                                         Transaction transaction)

Specified by:

createTransactionalObject in interface TransactionalService

rollbackTransaction

public void rollbackTransaction(String transactionId)

Specified by:

rollbackTransaction in interface TransactionalService

getStats

public Map<String,LocalQueueStats> getStats()

Description copied from interface: StatisticsAwareService

Return the service statistics for the local instance.

Specified by:

getStats in interface StatisticsAwareService<LocalQueueStats>

Returns:

the statistics, grouped by distributed object name

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