org.jboss.ha.framework.server
Class HASingletonImpl<E extends EventObject>

java.lang.Object
  org.jboss.ha.framework.server.HAServiceImpl<E>
      org.jboss.ha.framework.server.HASingletonImpl<E>

All Implemented Interfaces:

EventListener, DistributedReplicantManager.ReplicantListener, HAService<E>, HAServiceKeyProvider, HASingleton<E>, HASingletonLifecycle, HASingletonMBean, EventFacility<E>, HAServiceRpcHandler<E>, HASingletonRpcHandler<E>

public class HASingletonImpl<E extends EventObject>
extends HAServiceImpl<E>
implements HASingleton<E>, HASingletonRpcHandler<E>

Base class for HA-singleton based services.

Author:

Paul Ferraro

Nested Class Summary

protected class

HASingletonImpl.RpcHandler

Field Summary

Fields inherited from class org.jboss.ha.framework.server.HAServiceImpl

log

Fields inherited from interface org.jboss.ha.framework.interfaces.HASingleton

HASINGLETON_STARTED_NOTIFICATION, HASINGLETON_STARTING_NOTIFICATION, HASINGLETON_STOPPED_NOTIFICATION, HASINGLETON_STOPPING_NOTIFICATION

Constructor Summary

HASingletonImpl(EventFactory<E> eventFactory)

HASingletonImpl(EventFactory<E> eventFactory, EventFacility<E> eventHandler, HASingletonLifecycle singletonLifecycle)

Method Summary

protected List<ClusterNode>	getElectionCandidates()
HASingletonElectionPolicy	getElectionPolicy() Gets the policy used to determine which cluster node will become the master when the service topology changes.
boolean	getRestartOnMerge() Gets whether this singleton will stop and restart itself if it is the master and a cluster merge occurs.
protected HAServiceRpcHandler<E>	getRpcHandler()
protected boolean	isDRMMasterReplica()
boolean	isMasterNode() True if this cluster node has the active mbean singleton, false otherwise
protected void	makeThisNodeMaster()
protected void	partitionTopologyChanged(List<?> newReplicants, int newViewID, boolean merge) When topology changes, a new master is elected based on the result of the isDRMMasterReplica() call.
protected void	restartMaster()
void	setElectionPolicy(HASingletonElectionPolicy electionPolicy) Sets the policy used to determine which cluster node will become the master when the service topology changes.
void	setRestartOnMerge(boolean restart) Sets whether this singleton will stop and restart itself if it is the master and a cluster merge occurs.
protected void	startNewMaster()
void	startSingleton() Invoked when this mbean is elected to run the singleton service, or in other words when this node is elected for master.
protected void	stopIfMaster()
void	stopOldMaster()
void	stopSingleton() Invoked when this mbean is elected to no longer run the singleton service, or in other words when this node is elected for slave.

Methods inherited from class org.jboss.ha.framework.server.HAServiceImpl

addEventListener, callAsyncMethodOnPartition, callMethodOnPartition, create, destroy, getEventFacility, getEventFactory, getHAPartition, getHAServiceKey, getReplicant, getServiceHAName, handleEvent, isRegisterThreadContextClassLoader, notifyListeners, registerDRMListener, registerRPCHandler, removeEventListener, replicantsChanged, setHAPartition, setRegisterThreadContextClassLoader, setServiceHAName, start, stop, unregisterDRMListener, unregisterRPCHandler

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.ha.framework.interfaces.HAService

create, destroy, getServiceHAName, isRegisterThreadContextClassLoader, setHAPartition, setRegisterThreadContextClassLoader, setServiceHAName, start, stop

Methods inherited from interface org.jboss.ha.framework.interfaces.HAServiceKeyProvider

getHAPartition, getHAServiceKey

Methods inherited from interface org.jboss.ha.framework.interfaces.EventListener

handleEvent

Methods inherited from interface org.jboss.ha.framework.interfaces.EventListener

handleEvent

Constructor Detail

HASingletonImpl

public HASingletonImpl(EventFactory<E> eventFactory,
                       EventFacility<E> eventHandler,
                       HASingletonLifecycle singletonLifecycle)

HASingletonImpl

public HASingletonImpl(EventFactory<E> eventFactory)

Method Detail

getElectionPolicy

public HASingletonElectionPolicy getElectionPolicy()

Description copied from interface: HASingleton

Gets the policy used to determine which cluster node will become the master when the service topology changes.

Specified by:

getElectionPolicy in interface HASingleton<E extends EventObject>

Returns:

the policy. Can be null.

setElectionPolicy

public void setElectionPolicy(HASingletonElectionPolicy electionPolicy)

Description copied from interface: HASingleton

Sets the policy used to determine which cluster node will become the master when the service topology changes. Injection of common attributes into the election policy should be done during createService() method call.

Specified by:

setElectionPolicy in interface HASingleton<E extends EventObject>

Parameters:

electionPolicy - the policy. Can be null.

getRestartOnMerge

public boolean getRestartOnMerge()

Description copied from interface: HASingleton

Gets whether this singleton will stop and restart itself if it is the master and a cluster merge occurs.

A restart allows the service to reset any state that may have gotten out-of-sync with the rest of the cluster while the just-merged split was in effect.

Specified by:

getRestartOnMerge in interface HASingleton<E extends EventObject>

Returns:

true if a restart will occur, false otherwise

setRestartOnMerge

public void setRestartOnMerge(boolean restart)

Description copied from interface: HASingleton

Sets whether this singleton will stop and restart itself if it is the master and a cluster merge occurs.

A restart allows the service to reset any state that may have gotten out-of-sync with the rest of the cluster while the just-merged split was in effect.

Specified by:

setRestartOnMerge in interface HASingleton<E extends EventObject>

Parameters:

restart - true if a restart should occur, false otherwise. Default is true.

isMasterNode

public boolean isMasterNode()

Description copied from interface: HASingletonMBean

True if this cluster node has the active mbean singleton, false otherwise

Specified by:

isMasterNode in interface HASingletonMBean

startSingleton

public void startSingleton()

Description copied from interface: HASingletonLifecycle

Invoked when this mbean is elected to run the singleton service, or in other words when this node is elected for master.

Specified by:

startSingleton in interface HASingletonLifecycle

See Also:

HASingletonLifecycle.startSingleton()

stopSingleton

public void stopSingleton()

Description copied from interface: HASingletonLifecycle

Invoked when this mbean is elected to no longer run the singleton service, or in other words when this node is elected for slave.

Specified by:

stopSingleton in interface HASingletonLifecycle

See Also:

HASingletonLifecycle.stopSingleton()

partitionTopologyChanged

protected void partitionTopologyChanged(List<?> newReplicants,
                                        int newViewID,
                                        boolean merge)

When topology changes, a new master is elected based on the result of the isDRMMasterReplica() call.

Overrides:

partitionTopologyChanged in class HAServiceImpl<E extends EventObject>

See Also:

HAServiceImpl.partitionTopologyChanged(java.util.List, int, boolean), DistributedReplicantManager.isMasterReplica(String)

getElectionCandidates

protected List<ClusterNode> getElectionCandidates()

stopOldMaster

public void stopOldMaster()
                   throws Exception

Specified by:

stopOldMaster in interface HASingletonRpcHandler<E extends EventObject>

Throws:

Exception

See Also:

org.jboss.ha.singleton.HASingleton.RpcHandler#stopOldMaster()

isDRMMasterReplica

protected boolean isDRMMasterReplica()

makeThisNodeMaster

protected void makeThisNodeMaster()

startNewMaster

protected void startNewMaster()

restartMaster

protected void restartMaster()

stopIfMaster

protected void stopIfMaster()

getRpcHandler

protected HAServiceRpcHandler<E> getRpcHandler()

Overrides:

getRpcHandler in class HAServiceImpl<E extends EventObject>