org.onosproject.store.cluster.impl

Class HazelcastLeadershipService

java.lang.Object

org.onosproject.store.cluster.impl.HazelcastLeadershipService

All Implemented Interfaces:

org.onosproject.cluster.LeadershipService

@Service
public class HazelcastLeadershipService
extends Object
implements org.onosproject.cluster.LeadershipService

Distributed implementation of LeadershipService that is based on Hazelcast.

The election is eventually-consistent: if there is Hazelcast partitioning, and the partitioning is healed, there could be a short window of time until the leaders in each partition discover each other. If this happens, the leaders release the leadership and run again for election.

The leader election is based on Hazelcast's Global Lock, which is stongly consistent. In addition, each leader periodically advertises events (using a Hazelcast Topic) that it is the elected leader. Those events are used for two purposes: (1) Discover multi-leader collisions (in case of healed Hazelcast partitions), and (2) Inform all listeners who is the current leader (e.g., for informational purpose).

Field Summary

Fields

Modifier and Type	Field and Description
protected org.onosproject.store.cluster.messaging.ClusterCommunicationService	clusterCommunicator
protected org.onosproject.cluster.ClusterService	clusterService
protected org.onosproject.event.EventDeliveryService	eventDispatcher
protected StoreService	storeService

Constructor Summary

Constructors

Constructor and Description
HazelcastLeadershipService()

Method Summary

Modifier and Type	Method and Description
protected void	activate()
void	addListener(org.onosproject.cluster.LeadershipEventListener listener)
protected void	deactivate()
org.onosproject.cluster.NodeId	getLeader(String path)
Map<String,org.onosproject.cluster.Leadership>	getLeaderBoard()
org.onosproject.cluster.Leadership	getLeadership(String path)
Set<String>	ownedTopics(org.onosproject.cluster.NodeId nodeId)
void	removeListener(org.onosproject.cluster.LeadershipEventListener listener)
void	runForLeadership(String path)
void	withdraw(String path)

Methods inherited from class java.lang.Object

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

Field Detail

clusterCommunicator

@Reference(cardinality=MANDATORY_UNARY)
protected org.onosproject.store.cluster.messaging.ClusterCommunicationService clusterCommunicator

clusterService

@Reference(cardinality=MANDATORY_UNARY)
protected org.onosproject.cluster.ClusterService clusterService

storeService

@Reference(cardinality=MANDATORY_UNARY)
protected StoreService storeService

eventDispatcher

@Reference(cardinality=MANDATORY_UNARY)
protected org.onosproject.event.EventDeliveryService eventDispatcher

Constructor Detail

HazelcastLeadershipService

public HazelcastLeadershipService()

Method Detail

activate

@Activate
protected void activate()

deactivate

@Deactivate
protected void deactivate()

getLeader

public org.onosproject.cluster.NodeId getLeader(String path)

Specified by:

getLeader in interface org.onosproject.cluster.LeadershipService

getLeadership

public org.onosproject.cluster.Leadership getLeadership(String path)

Specified by:

getLeadership in interface org.onosproject.cluster.LeadershipService

ownedTopics

public Set<String> ownedTopics(org.onosproject.cluster.NodeId nodeId)

Specified by:

ownedTopics in interface org.onosproject.cluster.LeadershipService

runForLeadership

public void runForLeadership(String path)

Specified by:

runForLeadership in interface org.onosproject.cluster.LeadershipService

withdraw

public void withdraw(String path)

Specified by:

withdraw in interface org.onosproject.cluster.LeadershipService

getLeaderBoard

public Map<String,org.onosproject.cluster.Leadership> getLeaderBoard()

Specified by:

getLeaderBoard in interface org.onosproject.cluster.LeadershipService

addListener

public void addListener(org.onosproject.cluster.LeadershipEventListener listener)

Specified by:

addListener in interface org.onosproject.cluster.LeadershipService

removeListener

public void removeListener(org.onosproject.cluster.LeadershipEventListener listener)

Specified by:

removeListener in interface org.onosproject.cluster.LeadershipService