org.onosproject.store.primitives.resources.impl

Class AtomixLeaderElector

java.lang.Object

io.atomix.resource.AbstractResource<AtomixLeaderElector>

org.onosproject.store.primitives.resources.impl.AtomixLeaderElector

All Implemented Interfaces:

io.atomix.catalyst.util.Managed<AtomixLeaderElector>, io.atomix.resource.Resource<AtomixLeaderElector>, AsyncLeaderElector, DistributedPrimitive

public class AtomixLeaderElector
extends io.atomix.resource.AbstractResource<AtomixLeaderElector>
implements AsyncLeaderElector

Distributed resource providing the AsyncLeaderElector primitive.

Nested Class Summary

Nested classes/interfaces inherited from interface org.onosproject.store.service.DistributedPrimitive

DistributedPrimitive.Status, DistributedPrimitive.Type

Nested classes/interfaces inherited from interface io.atomix.resource.Resource

io.atomix.resource.Resource.Config, io.atomix.resource.Resource.Event, io.atomix.resource.Resource.EventType, io.atomix.resource.Resource.Options, io.atomix.resource.Resource.State

Field Summary

Fields

Modifier and Type	Field and Description
static String	CHANGE_SUBJECT

Fields inherited from class io.atomix.resource.AbstractResource

client, config, options

Fields inherited from interface org.onosproject.store.service.DistributedPrimitive

DEFAULT_OPERTATION_TIMEOUT_MILLIS

Constructor Summary

Constructors

Constructor and Description
AtomixLeaderElector(io.atomix.copycat.client.CopycatClient client, Properties properties)

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Void>	addChangeListener(Consumer<Change<Leadership>> consumer) Registers a listener to be notified of Leadership changes for all topics.
void	addStatusChangeListener(Consumer<DistributedPrimitive.Status> listener) Registers a listener to be called when the primitive's status changes.
CompletableFuture<Boolean>	anoint(String topic, NodeId nodeId) Attempts to promote a node to leadership displacing the current leader.
CompletableFuture<Void>	destroy() Purges state associated with this primitive.
CompletableFuture<Void>	evict(NodeId nodeId) Attempts to evict a node from all leadership elections it is registered for.
CompletableFuture<Set<String>>	getElectedTopics(NodeId nodeId)
CompletableFuture<Leadership>	getLeadership(String topic) Returns the Leadership for the specified topic.
CompletableFuture<Map<String,Leadership>>	getLeaderships() Returns the current Leaderships for all topics.
String	name() Returns the name of this primitive.
CompletableFuture<AtomixLeaderElector>	open()
CompletableFuture<Boolean>	promote(String topic, NodeId nodeId) Attempts to promote a node to top of candidate list without displacing the current leader.
CompletableFuture<Void>	removeChangeListener(Consumer<Change<Leadership>> consumer) Unregisters a previously registered change notification listener.
void	removeStatusChangeListener(Consumer<DistributedPrimitive.Status> listener) Unregisters a previously registered listener to be called when the primitive's status changes.
CompletableFuture<Leadership>	run(String topic, NodeId nodeId) Attempts to become leader for a topic.
CompletableFuture<AtomixLeaderElector>	setupCache()
Collection<Consumer<DistributedPrimitive.Status>>	statusChangeListeners() Returns the collection of status change listeners previously registered.
CompletableFuture<Void>	withdraw(String topic) Withdraws from leadership race for a topic.

Methods inherited from class io.atomix.resource.AbstractResource

close, config, context, delete, equals, hashCode, isClosed, isOpen, onEvent, onRecovery, onStateChange, options, recover, serializer, state, toString, type

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.onosproject.store.service.AsyncLeaderElector

asLeaderElector, asLeaderElector, primitiveType

Methods inherited from interface org.onosproject.store.service.DistributedPrimitive

applicationId

Field Detail

CHANGE_SUBJECT

public static final String CHANGE_SUBJECT

See Also:

Constant Field Values

Constructor Detail

AtomixLeaderElector

public AtomixLeaderElector(io.atomix.copycat.client.CopycatClient client,
                           Properties properties)

Method Detail

destroy

public CompletableFuture<Void> destroy()

Description copied from interface: DistributedPrimitive

Purges state associated with this primitive.

Implementations can override and provide appropriate clean up logic for purging any state state associated with the primitive. Whether modifications made within the destroy method have local or global visibility is left unspecified.

Specified by:

destroy in interface DistributedPrimitive

Returns:

CompletableFuture that is completed when the operation completes

name

public String name()

Description copied from interface: DistributedPrimitive

Returns the name of this primitive.

Specified by:

name in interface DistributedPrimitive

Returns:

name

open

public CompletableFuture<AtomixLeaderElector> open()

Specified by:

open in interface io.atomix.catalyst.util.Managed<AtomixLeaderElector>

Specified by:

open in interface io.atomix.resource.Resource<AtomixLeaderElector>

Overrides:

open in class io.atomix.resource.AbstractResource<AtomixLeaderElector>

setupCache

public CompletableFuture<AtomixLeaderElector> setupCache()

run

public CompletableFuture<Leadership> run(String topic,
                                         NodeId nodeId)

Description copied from interface: AsyncLeaderElector

Attempts to become leader for a topic.

Specified by:

run in interface AsyncLeaderElector

Parameters:

topic - leadership topic

nodeId - instance identifier of the node

Returns:

CompletableFuture that is completed with the current Leadership state of the topic

withdraw

public CompletableFuture<Void> withdraw(String topic)

Description copied from interface: AsyncLeaderElector

Withdraws from leadership race for a topic.

Specified by:

withdraw in interface AsyncLeaderElector

Parameters:

topic - leadership topic

Returns:

CompletableFuture that is completed when the withdraw is done

anoint

public CompletableFuture<Boolean> anoint(String topic,
                                         NodeId nodeId)

Description copied from interface: AsyncLeaderElector

Attempts to promote a node to leadership displacing the current leader.

Specified by:

anoint in interface AsyncLeaderElector

Parameters:

topic - leadership topic

nodeId - instance identifier of the new leader

Returns:

CompletableFuture that is completed with a boolean when the operation is done. Boolean is true if leadership transfer was successfully executed; false if it failed. This operation can fail (i.e. return false) if the node to be made new leader is not registering to run for election for the topic.

promote

public CompletableFuture<Boolean> promote(String topic,
                                          NodeId nodeId)

Description copied from interface: AsyncLeaderElector

Attempts to promote a node to top of candidate list without displacing the current leader.

Specified by:

promote in interface AsyncLeaderElector

Parameters:

topic - leadership topic

nodeId - instance identifier of the new top candidate

Returns:

CompletableFuture that is completed with a boolean when the operation is done. Boolean is true if node is now the top candidate. This operation can fail (i.e. return false) if the node is not registered to run for election for the topic.

evict

public CompletableFuture<Void> evict(NodeId nodeId)

Description copied from interface: AsyncLeaderElector

Attempts to evict a node from all leadership elections it is registered for.

If the node is the current leader for a topic, this call will promote the next top candidate (if one exists) to leadership.

Specified by:

evict in interface AsyncLeaderElector

Parameters:

nodeId - node instance identifier

Returns:

CompletableFuture that is completed when the operation is done.

getLeadership

public CompletableFuture<Leadership> getLeadership(String topic)

Description copied from interface: AsyncLeaderElector

Returns the Leadership for the specified topic.

Specified by:

getLeadership in interface AsyncLeaderElector

Parameters:

topic - leadership topic

Returns:

CompletableFuture that is completed with the current Leadership state of the topic

getLeaderships

public CompletableFuture<Map<String,Leadership>> getLeaderships()

Description copied from interface: AsyncLeaderElector

Returns the current Leaderships for all topics.

Specified by:

getLeaderships in interface AsyncLeaderElector

Returns:

CompletableFuture that is completed with the topic to Leadership mapping

getElectedTopics

public CompletableFuture<Set<String>> getElectedTopics(NodeId nodeId)

addChangeListener

public CompletableFuture<Void> addChangeListener(Consumer<Change<Leadership>> consumer)

Description copied from interface: AsyncLeaderElector

Registers a listener to be notified of Leadership changes for all topics.

Specified by:

addChangeListener in interface AsyncLeaderElector

Parameters:

consumer - listener to notify

Returns:

CompletableFuture that is completed when the operation completes

removeChangeListener

public CompletableFuture<Void> removeChangeListener(Consumer<Change<Leadership>> consumer)

Description copied from interface: AsyncLeaderElector

Unregisters a previously registered change notification listener.

If the specified listener was not previously registered, this operation will be a noop.

Specified by:

removeChangeListener in interface AsyncLeaderElector

Parameters:

consumer - listener to remove

Returns:

CompletableFuture that is completed when the operation completes

addStatusChangeListener

public void addStatusChangeListener(Consumer<DistributedPrimitive.Status> listener)

Description copied from interface: DistributedPrimitive

Registers a listener to be called when the primitive's status changes.

Specified by:

addStatusChangeListener in interface DistributedPrimitive

Parameters:

listener - The listener to be called when the status changes.

removeStatusChangeListener

public void removeStatusChangeListener(Consumer<DistributedPrimitive.Status> listener)

Description copied from interface: DistributedPrimitive

Unregisters a previously registered listener to be called when the primitive's status changes.

Specified by:

removeStatusChangeListener in interface DistributedPrimitive

Parameters:

listener - The listener to unregister

statusChangeListeners

public Collection<Consumer<DistributedPrimitive.Status>> statusChangeListeners()

Description copied from interface: DistributedPrimitive

Returns the collection of status change listeners previously registered.

Specified by:

statusChangeListeners in interface DistributedPrimitive

Returns:

collection of status change listeners