com.hazelcast.ringbuffer.impl

Class RingbufferService

java.lang.Object

com.hazelcast.ringbuffer.impl.RingbufferService

All Implemented Interfaces:

FragmentedMigrationAwareService, ManagedService, MigrationAwareService, QuorumAwareService, RemoteService, SplitBrainHandlerService

public class RingbufferService
extends Object
implements ManagedService, RemoteService, FragmentedMigrationAwareService, QuorumAwareService, SplitBrainHandlerService

The SPI Service that deals with the Ringbuffer.

Field Summary

Fields

Modifier and Type	Field and Description
static String	SERVICE_NAME The ringbuffer service name which defines it in the node engine.
static String	TOPIC_RB_PREFIX Prefix of ringbuffers that are created for topics.

Constructor Summary

Constructors

Constructor and Description
RingbufferService(NodeEngineImpl nodeEngine)

Method Summary

Modifier and Type	Method and Description
void	addRingbuffer(int partitionId, RingbufferContainer ringbuffer, RingbufferConfig config)
void	beforeMigration(PartitionMigrationEvent partitionMigrationEvent) 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.
DistributedObject	createDistributedObject(String objectName) Creates a distributed object.
void	destroyContainer(int partitionId, ObjectNamespace namespace)
void	destroyDistributedObject(String name) Destroys a distributed object.
void	ensureQuorumPresent(String distributedObjectName, QuorumType requiredQuorumPermissionType)
Collection<ServiceNamespace>	getAllServiceNamespaces(PartitionReplicationEvent event) Returns all known namespaces for given replication event.
<T,E> RingbufferContainer<T,E>	getContainerOrNull(int partitionId, ObjectNamespace namespace) Returns the ringbuffer container if it already exists for the given partitionId and namespace.
ConcurrentMap<Integer,Map<ObjectNamespace,RingbufferContainer>>	getContainers()
<T,E> RingbufferContainer<T,E>	getOrCreateContainer(int partitionId, ObjectNamespace namespace, RingbufferConfig config) Return the ringbuffer containter for the specified namespace.
String	getQuorumName(String name) Gets the name of the quorum associated with specified operation name.
RingbufferConfig	getRingbufferConfig(String name)
static ObjectNamespace	getRingbufferNamespace(String name)
int	getRingbufferPartitionId(String ringbufferName)
void	init(NodeEngine nodeEngine, Properties properties) Initializes this service.
boolean	isKnownServiceNamespace(ServiceNamespace namespace) Returns true if namespace is known by this service, false otherwise
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.
Operation	prepareReplicationOperation(PartitionReplicationEvent event, Collection<ServiceNamespace> namespaces) Returns an operation to replicate service data and/or state for a specific partition replica and namespaces 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

TOPIC_RB_PREFIX

public static final String TOPIC_RB_PREFIX

Prefix of ringbuffers that are created for topics. Using a prefix prevents users accidentally retrieving the ringbuffer.

See Also:

Constant Field Values

SERVICE_NAME

public static final String SERVICE_NAME

The ringbuffer service name which defines it in the node engine.

See Also:

Constant Field Values

Constructor Detail

RingbufferService

public RingbufferService(NodeEngineImpl nodeEngine)

Method Detail

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)

getContainers

public ConcurrentMap<Integer,Map<ObjectNamespace,RingbufferContainer>> getContainers()

createDistributedObject

public DistributedObject 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 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

destroyContainer

public void destroyContainer(int partitionId,
                             ObjectNamespace namespace)

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 <T,E> RingbufferContainer<T,E> getOrCreateContainer(int partitionId,
                                                           ObjectNamespace namespace,
                                                           RingbufferConfig config)

Return the ringbuffer containter for the specified namespace. If there is no ringbuffer container, create it using the config.

Parameters:

namespace - the ringbuffer container namespace

config - the ringbuffer config. Used to create the container when the container doesn't exist

Returns:

the ringbuffer container

Throws:

NullPointerException - if the config is null

getContainerOrNull

public <T,E> RingbufferContainer<T,E> getContainerOrNull(int partitionId,
                                                         ObjectNamespace namespace)

Returns the ringbuffer container if it already exists for the given partitionId and namespace. Returns null if it doesn't exist.

Type Parameters:

T - the type of items in the ringbuffer container

E - the type of items in the ringbuffer

Parameters:

partitionId - the partition ID of the ringbuffer container

namespace - the namespace of the ringbuffer container

Returns:

the ringbuffer container or null if it has not been created

getRingbufferConfig

public RingbufferConfig getRingbufferConfig(String name)

getRingbufferNamespace

public static ObjectNamespace getRingbufferNamespace(String name)

getRingbufferPartitionId

public int getRingbufferPartitionId(String ringbufferName)

addRingbuffer

public void addRingbuffer(int partitionId,
                          RingbufferContainer ringbuffer,
                          RingbufferConfig config)

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

prepareReplicationOperation

public Operation prepareReplicationOperation(PartitionReplicationEvent event,
                                             Collection<ServiceNamespace> namespaces)

Description copied from interface: FragmentedMigrationAwareService

Returns an operation to replicate service data and/or state for a specific partition replica and namespaces on another cluster member. This method is very similar to MigrationAwareService.prepareReplicationOperation(PartitionReplicationEvent), instead of copying whole partition replica, allows copying only some portion of replica, specified by given namespaces.

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 FragmentedMigrationAwareService

Parameters:

event - replication event

namespaces - replica fragment namespaces to replicate

Returns:

replication operation or null if nothing will be replicated

See Also:

MigrationAwareService.prepareReplicationOperation(PartitionReplicationEvent)

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

getAllServiceNamespaces

public Collection<ServiceNamespace> getAllServiceNamespaces(PartitionReplicationEvent event)

Description copied from interface: FragmentedMigrationAwareService

Returns all known namespaces for given replication event.

Specified by:

getAllServiceNamespaces in interface FragmentedMigrationAwareService

Parameters:

event - replication event

Returns:

all known service namespaces for the replication

isKnownServiceNamespace

public boolean isKnownServiceNamespace(ServiceNamespace namespace)

Description copied from interface: FragmentedMigrationAwareService

Returns true if namespace is known by this service, false otherwise

Specified by:

isKnownServiceNamespace in interface FragmentedMigrationAwareService

Parameters:

namespace - namespace

Returns:

true if namespace is known by this service, false otherwise

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

ensureQuorumPresent

public void ensureQuorumPresent(String distributedObjectName,
                                QuorumType requiredQuorumPermissionType)

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