final class ClusterClient extends Actor with ActorLogging

This actor is intended to be used on an external node that is not member of the cluster. It acts like a gateway for sending messages to actors somewhere in the cluster. From the initial contact points it will establish a connection to a ClusterReceptionist somewhere in the cluster. It will monitor the connection to the receptionist and establish a new connection if the link goes down. When looking for a new receptionist it uses fresh contact points retrieved from previous establishment, or periodically refreshed contacts, i.e. not necessarily the initial contact points.

You can send messages via the ClusterClient to any actor in the cluster that is registered in the ClusterReceptionist. Messages are wrapped in ClusterClient.Send, ClusterClient.SendToAll or ClusterClient.Publish.

1. ClusterClient.Send - The message will be delivered to one recipient with a matching path, if any such exists. If several entries match the path the message will be delivered to one random destination. The sender of the message can specify that local affinity is preferred, i.e. the message is sent to an actor in the same local actor system as the used receptionist actor, if any such exists, otherwise random to any other matching entry.

2. ClusterClient.SendToAll - The message will be delivered to all recipients with a matching path.

3. ClusterClient.Publish - The message will be delivered to all recipients Actors that have been registered as subscribers to to the named topic.

Use the factory method ClusterClient#props) to create the akka.actor.Props for the actor.

If the receptionist is not currently available, the client will buffer the messages and then deliver them when the connection to the receptionist has been established. 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 client.

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

Annotations
@deprecated
Deprecated

(Since version 2.6.0) Use Akka gRPC instead, see https://doc.akka.io/libraries/akka-core/2.6/cluster-client.html#migration-to-akka-grpc

Source
ClusterClient.scala
Linear Supertypes
ActorLogging, Actor, AnyRef, Any
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  1. ClusterClient
  2. ActorLogging
  3. Actor
  4. AnyRef
  5. Any
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Visibility
  1. Public
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Instance Constructors

  1. new ClusterClient(settings: ClusterClientSettings)

Type Members

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

Value Members

  1. def active(receptionist: ActorRef): actor.Actor.Receive
  2. def buffer(msg: Any): Unit
  3. var buffer: MessageBuffer
  4. var contactPaths: HashSet[ActorPath]
  5. var contactPathsPublished: HashSet[ActorPath]
  6. def contactPointMessages: actor.Actor.Receive
  7. var contacts: HashSet[ActorSelection]
  8. 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
  9. def establishing: actor.Actor.Receive
  10. val failureDetector: DeadlineFailureDetector
  11. val heartbeatTask: Cancellable
  12. val initialContactsSel: HashSet[ActorSelection]
  13. def log: LoggingAdapter
    Definition Classes
    ActorLogging
  14. 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])
  15. def postStop(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    ClusterClient → Actor
  16. 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])
  17. 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
    Actor
    Annotations
    @throws(classOf[Exception])
  18. def publishContactPoints(): Unit
  19. 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
    ClusterClient → Actor
  20. def reestablish(): Unit
  21. var refreshContactsTask: Option[Cancellable]
  22. def scheduleRefreshContactsTick(interval: FiniteDuration): Unit
  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(receptionist: ActorRef): Unit
  25. def sendGetContacts(): Unit
  26. 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
  27. var subscribers: Vector[ActorRef]
  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 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