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Akka.NETDistributedPubSubMediator Class

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 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. 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. 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. 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. 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 Send and all messages are delivered to one subscribe. If all the subscribed actors have different group names, then this works like normal Publish and all messages are broadcast to all subscribers.

You register actors to the local mediator with Put or 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 Remove or Unsubscribe.

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

Inheritance Hierarchy

Namespace:  Akka.Cluster.Tools.PublishSubscribe
Assembly:  Akka.Cluster.Tools (in Akka.Cluster.Tools.dll) Version: 1.2.3.42 (1.2.3.42)
Syntax
public class DistributedPubSubMediator : ReceiveActor

The DistributedPubSubMediator type exposes the following members.

Constructors
  NameDescription
Public methodDistributedPubSubMediator
TBD
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Properties
  NameDescription
Public propertyLog
TBD
Public propertyOwnVersions
TBD
Protected propertySelf
Gets the self ActorRef
(Inherited from ActorBase.)
Protected propertySender
Gets the sending ActorRef of the current message
(Inherited from ActorBase.)
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Methods
  NameDescription
Public methodAroundPostRestart
Can be overridden to intercept calls to `PostRestart`. Calls `PostRestart` by default.
(Inherited from ActorBase.)
Public methodAroundPostStop
Can be overridden to intercept calls to `PostStop`. Calls `PostStop` by default..
(Inherited from ActorBase.)
Public methodAroundPreRestart
Can be overridden to intercept calls to `PreRestart`. Calls `PreRestart` by default.
(Inherited from ActorBase.)
Public methodAroundPreStart
Can be overridden to intercept calls to `PreStart`. Calls `PreStart` by default.
(Inherited from ActorBase.)
Protected methodAroundReceive
TBD
(Inherited from ActorBase.)
Protected methodBecome(Action)
Changes the actor's behavior and replaces the current receive handler with the specified handler.
(Inherited from ReceiveActor.)
Protected methodBecome(Receive)
Changes the actor's command behavior and replaces the current receive handler with the specified handler.
(Inherited from ActorBase.)
Protected methodBecome(UntypedReceive)
Changes the actor's behavior and replaces the current receive handler with the specified handler.
(Inherited from UntypedActor.)
Protected methodBecomeStacked(Action)
Changes the actor's behavior and replaces the current receive handler with the specified handler. The current handler is stored on a stack, and you can revert to it by calling UnbecomeStacked
Remarks
Please note, that in order to not leak memory, make sure every call to BecomeStacked(Action) is matched with a call to UnbecomeStacked.
(Inherited from ReceiveActor.)
Protected methodBecomeStacked(Receive)
Changes the actor's behavior and replaces the current receive handler with the specified handler. The current handler is stored on a stack, and you can revert to it by calling UnbecomeStacked
Remarks
Please note, that in order to not leak memory, make sure every call to BecomeStacked(Receive) is matched with a call to UnbecomeStacked.
(Inherited from ActorBase.)
Protected methodBecomeStacked(UntypedReceive)
Changes the actor's behavior and replaces the current receive handler with the specified handler. The current handler is stored on a stack, and you can revert to it by calling UnbecomeStacked
Remarks
Please note, that in order to not leak memory, make sure every call to BecomeStacked(UntypedReceive) is matched with a call to UnbecomeStacked.
(Inherited from UntypedActor.)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodOnReceive
TBD
(Inherited from ReceiveActor.)
Protected methodPostRestart
User overridable callback: By default it calls `PreStart()`.

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

(Inherited from ActorBase.)
Protected methodPostStop
TBD
(Overrides ActorBasePostStop.)
Protected methodPreRestart
User overridable callback: '''By default it disposes of all children and then calls `postStop()`.'''

Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.

(Inherited from ActorBase.)
Protected methodPreStart
TBD
(Overrides ActorBasePreStart.)
Public methodStatic memberProps
TBD
Protected methodReceive(Object)
TBD
(Inherited from UntypedActor.)
Protected methodReceive(Type, FuncObject, Boolean)
Registers a handler for incoming messages of the specified messageType. The handler should return true if it has handled the message. If the handler returns true no more handlers will be tried; otherwise the next registered handler will be tried.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceive(Type, ActionObject, PredicateObject)
Registers a handler for incoming messages of the specified messageType. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceive(Type, PredicateObject, ActionObject)
Registers a handler for incoming messages of the specified messageType. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveT(FuncT, Boolean)
Registers a handler for incoming messages of the specified type T. The handler should return true if it has handled the message. If the handler returns true no more handlers will be tried; otherwise the next registered handler will be tried.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveT(ActionT, PredicateT)
Registers a handler for incoming messages of the specified type T. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveT(PredicateT, ActionT)
Registers a handler for incoming messages of the specified type T. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAny
Registers a handler for incoming messages of any type.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAnyAsync
Registers an asynchronous handler for incoming messages of any type.
Remarks
The actor will be suspended until the task returned by handler completes.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAsync(Type, FuncObject, Task, PredicateObject)
Registers an asynchronous handler for incoming messages of the specified messageType. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
The actor will be suspended until the task returned by handler completes.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAsync(Type, PredicateObject, FuncObject, Task)
Registers an asynchronous handler for incoming messages of the specified messageType. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
The actor will be suspended until the task returned by handler completes.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAsyncT(FuncT, Task, PredicateT)
Registers an asynchronous handler for incoming messages of the specified type T. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
The actor will be suspended until the task returned by handler completes.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodReceiveAsyncT(PredicateT, FuncT, Task)
Registers an asynchronous handler for incoming messages of the specified type T. If shouldHandle!=null then it must return true before a message is passed to handler.
Remarks
The actor will be suspended until the task returned by handler completes.
Remarks
This method may only be called when constructing the actor or from Become(Action) or BecomeStacked(Action).
Remarks
Note that handlers registered prior to this may have handled the message already. In that case, this handler will not be invoked.
(Inherited from ReceiveActor.)
Protected methodRunTask(Action)
TBD
(Inherited from UntypedActor.)
Protected methodRunTask(FuncTask)
TBD
(Inherited from UntypedActor.)
Protected methodSetReceiveTimeout

Defines the inactivity timeout after which the sending of a ReceiveTimeout message is triggered. When specified, the receive function should be able to handle a ReceiveTimeout message.

Please note that the receive timeout might fire and enqueue the ReceiveTimeout message right after another message was enqueued; hence it is not guaranteed that upon reception of the receive timeout there must have been an idle period beforehand as configured via this method.

Once set, the receive timeout stays in effect (i.e. continues firing repeatedly after inactivity periods). Pass in null to switch off this feature.

(Inherited from ActorBase.)
Protected methodSupervisorStrategy
TBD
(Inherited from ActorBase.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Protected methodUnbecomeStacked
Reverts the Actor behavior to the previous one on the behavior stack.
(Inherited from ActorBase.)
Protected methodUnhandled
Is called when a message isn't handled by the current behavior of the actor by default it fails with either a DeathPactException (in case of an unhandled Terminated message) or publishes an UnhandledMessage to the actor's system's EventStream
(Inherited from ActorBase.)
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Extension Methods
See Also