akka.cluster.singleton

Class ClusterSingletonProxy

java.lang.Object

akka.cluster.singleton.ClusterSingletonProxy

All Implemented Interfaces:

Actor, ActorLogging

public final class ClusterSingletonProxy
extends java.lang.Object
implements Actor, ActorLogging

The ClusterSingletonProxy works together with the ClusterSingletonManager to provide a distributed proxy to the singleton actor.

The proxy can be started on every node where the singleton needs to be reached and used as if it were the singleton itself. It will then act as a router to the currently running singleton instance. If the singleton is not currently available, e.g., during hand off or startup, the proxy will buffer the messages sent to the singleton and then deliver them when the singleton is finally available. The size of the buffer is configurable and it can be disabled by using a buffer size of 0. When the buffer is full old messages will be dropped when new messages are sent via the proxy.

The proxy works by keeping track of the oldest cluster member. When a new oldest member is identified, e.g. because the older one left the cluster, or at startup, the proxy will try to identify the singleton on the oldest member by periodically sending an Identify message until the singleton responds with its ActorIdentity.

Note that this is a best effort implementation: messages can always be lost due to the distributed nature of the actors involved.

Nested Class Summary

Nested classes/interfaces inherited from interface akka.actor.Actor

Actor.emptyBehavior$, Actor.ignoringBehavior$

Constructor Summary

Constructors

Constructor and Description
ClusterSingletonProxy(java.lang.String singletonManagerPath, ClusterSingletonProxySettings settings)

Method Summary

Modifier and Type	Method and Description
void	add(Member m) Adds new member if it has the right role.
scala.math.Ordering<Member>	ageOrdering()
protected abstract static void	akka$actor$Actor$_setter_$context_$eq(ActorContext x$1)
protected abstract static void	akka$actor$Actor$_setter_$self_$eq(ActorRef x$1)
static void	akka$actor$ActorLogging$$_log_$eq(LoggingAdapter x$1)
static LoggingAdapter	akka$actor$ActorLogging$$_log()
protected static void	aroundPostRestart(java.lang.Throwable reason)
protected static void	aroundPostStop()
protected static void	aroundPreRestart(java.lang.Throwable reason, scala.Option<java.lang.Object> message)
protected static void	aroundPreStart()
protected static void	aroundReceive(scala.PartialFunction<java.lang.Object,scala.runtime.BoxedUnit> receive, java.lang.Object msg)
MessageBuffer	buffer()
void	buffer(java.lang.Object msg)
void	cancelTimer()
Cluster	cluster()
ActorContext	context() Stores the context for this actor, including self, and sender.
java.lang.String	createIdentifyId(int i)
void	handleInitial(ClusterEvent.CurrentClusterState state)
int	identifyCounter()
java.lang.String	identifyId()
void	identifySingleton() Discard old singleton ActorRef and send a periodic message to self to identify the singleton.
scala.Option<Cancellable>	identifyTimer()
static LoggingAdapter	log()
boolean	matchingRole(Member member)
scala.collection.immutable.SortedSet<Member>	membersByAge()
static void	postRestart(java.lang.Throwable reason)
void	postStop() User overridable callback.
static void	preRestart(java.lang.Throwable reason, scala.Option<java.lang.Object> message)
void	preStart() User overridable callback.
static Props	props(java.lang.String singletonManagerPath, ClusterSingletonProxySettings settings) Scala API: Factory method for ClusterSingletonProxy Props.
scala.PartialFunction<java.lang.Object,scala.runtime.BoxedUnit>	receive() This defines the initial actor behavior, it must return a partial function with the actor logic.
void	remove(Member m) Removes a member.
ActorRef	self() The 'self' field holds the ActorRef for this actor.
void	sendBuffered()
static ActorRef	sender()
scala.Option<ActorRef>	singleton()
java.lang.String[]	singletonPath()
static SupervisorStrategy	supervisorStrategy()
void	trackChange(scala.Function0<scala.runtime.BoxedUnit> block)
static void	unhandled(java.lang.Object message)

Methods inherited from class java.lang.Object

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

Methods inherited from interface akka.actor.Actor

aroundPostRestart, aroundPostStop, aroundPreRestart, aroundPreStart, aroundReceive, postRestart, preRestart, sender, supervisorStrategy, unhandled

Methods inherited from interface akka.actor.ActorLogging

log

Constructor Detail

ClusterSingletonProxy

public ClusterSingletonProxy(java.lang.String singletonManagerPath,
                             ClusterSingletonProxySettings settings)

Method Detail

props

public static Props props(java.lang.String singletonManagerPath,
                          ClusterSingletonProxySettings settings)

Scala API: Factory method for ClusterSingletonProxy Props.

Parameters:

singletonManagerPath - The logical path of the singleton manager, e.g. /user/singletonManager, which ends with the name you defined in actorOf when creating the ClusterSingletonManager.

settings - see ClusterSingletonProxySettings

Returns:

(undocumented)

sender

public static final ActorRef sender()

aroundReceive

protected static void aroundReceive(scala.PartialFunction<java.lang.Object,scala.runtime.BoxedUnit> receive,
                                    java.lang.Object msg)

aroundPreStart

protected static void aroundPreStart()

aroundPostStop

protected static void aroundPostStop()

aroundPreRestart

protected static void aroundPreRestart(java.lang.Throwable reason,
                                       scala.Option<java.lang.Object> message)

aroundPostRestart

protected static void aroundPostRestart(java.lang.Throwable reason)

supervisorStrategy

public static SupervisorStrategy supervisorStrategy()

preRestart

public static void preRestart(java.lang.Throwable reason,
                              scala.Option<java.lang.Object> message)
                       throws java.lang.Exception

Throws:

java.lang.Exception

postRestart

public static void postRestart(java.lang.Throwable reason)
                        throws java.lang.Exception

Throws:

java.lang.Exception

unhandled

public static void unhandled(java.lang.Object message)

akka$actor$Actor$_setter_$context_$eq

protected abstract static void akka$actor$Actor$_setter_$context_$eq(ActorContext x$1)

akka$actor$Actor$_setter_$self_$eq

protected abstract static void akka$actor$Actor$_setter_$self_$eq(ActorRef x$1)

akka$actor$ActorLogging$$_log

public static LoggingAdapter akka$actor$ActorLogging$$_log()

akka$actor$ActorLogging$$_log_$eq

public static void akka$actor$ActorLogging$$_log_$eq(LoggingAdapter x$1)

log

public static LoggingAdapter log()

context

public ActorContext context()

Description copied from interface: Actor

Stores the context for this actor, including self, and sender. It is implicit to support operations such as forward.

WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

ActorContext is the Scala API. getContext returns a UntypedActorContext, which is the Java API of the actor context.

Specified by:

context in interface Actor

Returns:

(undocumented)

self

public final ActorRef self()

Description copied from interface: Actor

The 'self' field holds the ActorRef for this actor.

Can be used to send messages to itself:

 self ! message
 

Specified by:

self in interface Actor

Returns:

(undocumented)

singletonPath

public java.lang.String[] singletonPath()

identifyCounter

public int identifyCounter()

identifyId

public java.lang.String identifyId()

createIdentifyId

public java.lang.String createIdentifyId(int i)

identifyTimer

public scala.Option<Cancellable> identifyTimer()

cluster

public Cluster cluster()

singleton

public scala.Option<ActorRef> singleton()

ageOrdering

public scala.math.Ordering<Member> ageOrdering()

membersByAge

public scala.collection.immutable.SortedSet<Member> membersByAge()

buffer

public MessageBuffer buffer()

preStart

public void preStart()

Description copied from interface: Actor

User overridable callback.

Is called when an Actor is started. Actors are automatically started asynchronously when created. Empty default implementation.

Specified by:

preStart in interface Actor

postStop

public void postStop()

Description copied from interface: Actor

User overridable callback.

Is called asynchronously after 'actor.stop()' is invoked. Empty default implementation.

Specified by:

postStop in interface Actor

cancelTimer

public void cancelTimer()

matchingRole

public boolean matchingRole(Member member)

handleInitial

public void handleInitial(ClusterEvent.CurrentClusterState state)

identifySingleton

public void identifySingleton()

Discard old singleton ActorRef and send a periodic message to self to identify the singleton.

trackChange

public void trackChange(scala.Function0<scala.runtime.BoxedUnit> block)

add

public void add(Member m)

Adds new member if it has the right role.

Parameters:

m - New cluster member.

remove

public void remove(Member m)

Removes a member.

Parameters:

m - Cluster member to remove.

receive

public scala.PartialFunction<java.lang.Object,scala.runtime.BoxedUnit> receive()

Description copied from interface: Actor

This defines the initial actor behavior, it must return a partial function with the actor logic.

Specified by:

receive in interface Actor

Returns:

(undocumented)

buffer

public void buffer(java.lang.Object msg)

sendBuffered

public void sendBuffered()