Packages

class DistributedPubSubMediator extends Actor with ActorLogging with PerGroupingBuffer

This actor manages a registry of actor references and replicates the entries to peer actors among all cluster nodes or a group of nodes tagged with a specific role.

The DistributedPubSubMediator actor is supposed to be started on all nodes, or all nodes with specified role, in the cluster. The mediator can be started with the DistributedPubSub extension or as an ordinary actor.

Changes are only performed in the own part of the registry and those changes are versioned. Deltas are disseminated in a scalable way to other nodes with a gossip protocol. The registry is eventually consistent, i.e. changes are not immediately visible at other nodes, but typically they will be fully replicated to all other nodes after a few seconds.

You can send messages via the mediator on any node to registered actors on any other node. There is three modes of message delivery.

1. DistributedPubSubMediator.Send - The message will be delivered to one recipient with a matching path, if any such exists in the registry. If several entries match the path the message will be sent via the supplied routingLogic (default random) to one 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 mediator actor, if any such exists, otherwise route to any other matching entry. A typical usage of this mode is private chat to one other user in an instant messaging application. It can also be used for distributing tasks to registered workers, like a cluster aware router where the routees dynamically can register themselves.

2. DistributedPubSubMediator.SendToAll - The message will be delivered to all recipients with a matching path. Actors with the same path, without address information, can be registered on different nodes. On each node there can only be one such actor, since the path is unique within one local actor system. Typical usage of this mode is to broadcast messages to all replicas with the same path, e.g. 3 actors on different nodes that all perform the same actions, for redundancy.

3. DistributedPubSubMediator.Publish - Actors may be registered to a named topic instead of path. This enables many subscribers on each node. The message will be delivered to all subscribers of the topic. For efficiency the message is sent over the wire only once per node (that has a matching topic), and then delivered to all subscribers of the local topic representation. This is the true pub/sub mode. A typical usage of this mode is a chat room in an instant messaging application.

4. DistributedPubSubMediator.Publish with sendOneMessageToEachGroup - Actors may be subscribed to a named topic with an optional property group. If subscribing with a group name, each message published to a topic with the sendOneMessageToEachGroup flag is delivered via the supplied routingLogic (default random) to one actor within each subscribing group. If all the subscribed actors have the same group name, then this works just like DistributedPubSubMediator.Send and all messages are delivered to one subscribe. If all the subscribed actors have different group names, then this works like normal DistributedPubSubMediator.Publish and all messages are broadcast to all subscribers.

You register actors to the local mediator with DistributedPubSubMediator.Put or DistributedPubSubMediator.Subscribe. Put is used together with Send and SendToAll message delivery modes. The ActorRef in Put must belong to the same local actor system as the mediator. Subscribe is used together with Publish. Actors are automatically removed from the registry when they are terminated, or you can explicitly remove entries with DistributedPubSubMediator.Remove or DistributedPubSubMediator.Unsubscribe.

Successful Subscribe and Unsubscribe is acknowledged with DistributedPubSubMediator.SubscribeAck and DistributedPubSubMediator.UnsubscribeAck replies.

Not intended for subclassing by user code.

Annotations
@DoNotInherit()
Source
DistributedPubSubMediator.scala
Linear Supertypes
PerGroupingBuffer, ActorLogging, Actor, AnyRef, Any
Type Hierarchy
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Inherited
  1. DistributedPubSubMediator
  2. PerGroupingBuffer
  3. ActorLogging
  4. Actor
  5. AnyRef
  6. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new DistributedPubSubMediator(settings: DistributedPubSubSettings)

Type Members

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

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toany2stringadd[DistributedPubSubMediator] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (DistributedPubSubMediator, B)
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toArrowAssoc[DistributedPubSubMediator] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. def aroundPostRestart(reason: Throwable): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to postRestart. Calls postRestart by default.

    Attributes
    protected[pekko]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  7. def aroundPostStop(): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to postStop. Calls postStop by default.

    Attributes
    protected[pekko]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  8. def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to preRestart. Calls preRestart by default.

    Attributes
    protected[pekko]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  9. def aroundPreStart(): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to preStart. Calls preStart by default.

    Attributes
    protected[pekko]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  10. def aroundReceive(receive: actor.Actor.Receive, msg: Any): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to this actor's current behavior.

    receive

    current behavior.

    msg

    current message.

    Attributes
    protected[pekko]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  11. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  12. def bufferOr(grouping: String, message: Any, originalSender: ActorRef)(action: => Unit): Unit
    Definition Classes
    PerGroupingBuffer
  13. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native() @HotSpotIntrinsicCandidate()
  14. val cluster: Cluster
  15. def collectDelta(otherVersions: Map[Address, Long]): Iterable[Bucket]
  16. 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!

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

    Definition Classes
    Actor
  17. var deltaCount: Long
  18. def ensuring(cond: (DistributedPubSubMediator) => Boolean, msg: => Any): DistributedPubSubMediator
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toEnsuring[DistributedPubSubMediator] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  19. def ensuring(cond: (DistributedPubSubMediator) => Boolean): DistributedPubSubMediator
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toEnsuring[DistributedPubSubMediator] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  20. def ensuring(cond: Boolean, msg: => Any): DistributedPubSubMediator
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toEnsuring[DistributedPubSubMediator] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  21. def ensuring(cond: Boolean): DistributedPubSubMediator
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toEnsuring[DistributedPubSubMediator] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  22. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  23. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  24. def forwardMessages(grouping: String, recipient: ActorRef): Unit
    Definition Classes
    PerGroupingBuffer
  25. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  26. def getCurrentTopics(): Set[String]
  27. def gossip(): Unit

    Gossip to peer nodes.

  28. val gossipTask: Cancellable
  29. def gossipTo(address: Address): Unit
  30. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  31. def initializeGrouping(grouping: String): Unit
    Definition Classes
    PerGroupingBuffer
  32. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  33. def log: LoggingAdapter
    Definition Classes
    ActorLogging
  34. def matchingRole(m: Member): Boolean
  35. def mkKey(path: ActorPath): String
  36. def mkKey(ref: ActorRef): String
  37. def myVersions: Map[Address, Long]
  38. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  39. def newTopicActor(encTopic: String): ActorRef
  40. val nextVersion: () => Long
  41. var nodes: Set[Address]
  42. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  43. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  44. def otherHasNewerVersions(otherVersions: Map[Address, Long]): Boolean
  45. 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])
  46. def postStop(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    DistributedPubSubMediatorActor
  47. 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])
  48. 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
    DistributedPubSubMediatorActor
  49. def prune(): Unit
  50. val pruneInterval: FiniteDuration
  51. val pruneTask: Cancellable
  52. def publish(path: String, msg: Any, allButSelf: Boolean = false): Unit
  53. def publishToEachGroup(path: String, msg: Any): Unit
  54. def put(key: String, valueOption: Option[ActorRef]): Unit
  55. 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
    DistributedPubSubMediatorActor
  56. def recreateAndForwardMessagesIfNeeded(grouping: String, recipient: => ActorRef): Unit
    Definition Classes
    PerGroupingBuffer
  57. def registerTopic(ref: ActorRef): Unit
  58. var registry: Map[Address, Bucket]
  59. val removedTimeToLiveMillis: Long
  60. def selectRandomNode(addresses: IndexedSeq[Address]): Option[Address]
  61. 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
  62. 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 pekko.actor.ActorSystem.

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

    Definition Classes
    Actor
  63. 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
  64. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  65. def toString(): String
    Definition Classes
    AnyRef → Any
  66. 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 pekko.actor.DeathPactException (in case of an unhandled pekko.actor.Terminated message) or publishes an pekko.actor.UnhandledMessage to the actor's system's pekko.event.EventStream

    Definition Classes
    Actor
  67. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  68. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  69. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable]) @Deprecated @Deprecated
    Deprecated
  2. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toStringFormat[DistributedPubSubMediator] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

  3. def [B](y: B): (DistributedPubSubMediator, B)
    Implicit
    This member is added by an implicit conversion from DistributedPubSubMediator toArrowAssoc[DistributedPubSubMediator] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from PerGroupingBuffer

Inherited from ActorLogging

Inherited from Actor

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromDistributedPubSubMediator to any2stringadd[DistributedPubSubMediator]

Inherited by implicit conversion StringFormat fromDistributedPubSubMediator to StringFormat[DistributedPubSubMediator]

Inherited by implicit conversion Ensuring fromDistributedPubSubMediator to Ensuring[DistributedPubSubMediator]

Inherited by implicit conversion ArrowAssoc fromDistributedPubSubMediator to ArrowAssoc[DistributedPubSubMediator]

Ungrouped