final class ClusterSingletonProxy extends Actor with ActorLogging

The ClusterSingletonProxy works together with the akka.cluster.singleton.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 akka.actor.Identify message until the singleton responds with its akka.actor.ActorIdentity.

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

Annotations
@nowarn()
Source
ClusterSingletonProxy.scala
Linear Supertypes
ActorLogging, Actor, AnyRef, Any
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. ClusterSingletonProxy
  2. ActorLogging
  3. Actor
  4. AnyRef
  5. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new ClusterSingletonProxy(singletonManagerPath: String, settings: ClusterSingletonProxySettings)

Type Members

  1. type Receive = PartialFunction[Any, Unit]
    Definition Classes
    Actor

Value Members

  1. def add(m: Member): Unit

    Adds new member if it has the right role.

    Adds new member if it has the right role.

    m

    New cluster member.

  2. val ageOrdering: Ordering[Member]
  3. def buffer(msg: Any): Unit
  4. var buffer: MessageBuffer
  5. def cancelTimer(): Unit
  6. val cluster: Cluster
  7. implicit val context: ActorContext

    Scala API: Stores the context for this actor, including self, and sender.

    Scala API: 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!

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

    Definition Classes
    Actor
  8. def createIdentifyId(i: Int): String
  9. def handleInitial(state: CurrentClusterState): Unit
  10. var identifyCounter: Int
  11. var identifyId: String
  12. def identifySingleton(): Unit

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

  13. var identifyTimer: Option[Cancellable]
  14. def log: LoggingAdapter
    Definition Classes
    ActorLogging
  15. def matchingRole(member: Member): Boolean
  16. var membersByAge: SortedSet[Member]
  17. def postRestart(reason: Throwable): Unit

    User overridable callback: By default it calls preStart().

    User overridable callback: By default it calls preStart().

    reason

    the Throwable that caused the restart to happen Is called right AFTER restart on the newly created Actor to allow reinitialization after an Actor crash.

    Definition Classes
    Actor
    Annotations
    @throws(classOf[Exception])
  18. def postStop(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    ClusterSingletonProxy → Actor
  19. def preRestart(reason: Throwable, message: Option[Any]): Unit

    Scala API: User overridable callback: By default it disposes of all children and then calls postStop().

    Scala API: User overridable callback: By default it disposes of all children and then calls postStop().

    reason

    the Throwable that caused the restart to happen

    message

    optionally the current message the actor processed when failing, if applicable Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.

    Definition Classes
    Actor
    Annotations
    @throws(classOf[Exception])
  20. def preStart(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    ClusterSingletonProxy → Actor
  21. def receive: PartialFunction[Any, Unit]

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

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

    Definition Classes
    ClusterSingletonProxy → Actor
  22. def remove(m: Member): Unit

    Removes a member.

    Removes a member.

    m

    Cluster member to remove.

  23. implicit final val self: ActorRef

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

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

    Can be used to send messages to itself: 

    self ! message

    Definition Classes
    Actor
  24. def sendBuffered(): Unit
  25. final def sender(): ActorRef

    The reference sender Actor of the last received message.

    The reference sender Actor of the last received message. Is defined if the message was sent from another Actor, else deadLetters in akka.actor.ActorSystem.

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

    Definition Classes
    Actor
  26. var singleton: Option[ActorRef]
  27. val singletonPath: Array[String]
  28. def supervisorStrategy: SupervisorStrategy

    User overridable definition the strategy to use for supervising child actors.

    User overridable definition the strategy to use for supervising child actors.

    Definition Classes
    Actor
  29. def trackChange(block: () => Unit): Unit
  30. def unhandled(message: Any): Unit

    User overridable callback.

    User overridable callback.

    Is called when a message isn't handled by the current behavior of the actor by default it fails with either a akka.actor.DeathPactException (in case of an unhandled akka.actor.Terminated message) or publishes an akka.actor.UnhandledMessage to the actor's system's akka.event.EventStream

    Definition Classes
    Actor