The logical path of the singleton. This does not include the node address or actor system name, e.g., it can be something like /user/singletonManager/singleton.
Cluster role on which the singleton is deployed. This is required to keep track only of the members where the singleton can actually exist.
Periodicity at which the proxy sends the Identify
message to the current
singleton actor selection.
Adds new member if it has the right role.
Adds new member if it has the right role.
New cluster member.
Can be overridden to intercept calls to postRestart
.
Can be overridden to intercept calls to postStop
.
Can be overridden to intercept calls to preRestart
.
Can be overridden to intercept calls to preStart
.
INTERNAL API.
Stores the context for this actor, including self, and sender.
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.UntypedActorContext, which is the Java API of the actor
context.
Discard old singleton ActorRef and send a periodic message to self to identify the singleton.
User overridable callback: By default it calls preStart()
.
User overridable callback: By default it calls preStart()
.
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.
Overridden callback.
Overridden callback. Prepends all messages in the stash to the mailbox and clears the stash. Must be called when overriding this method, otherwise stashed messages won't be propagated to DeadLetters when actor stops.
Overridden callback.
Overridden callback. Prepends all messages in the stash to the mailbox, clears the stash, stops all children and invokes the postStop() callback.
the Throwable that caused the restart to happen
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.
User overridable callback.
User overridable callback.
Is called when an Actor is started. Actors are automatically started asynchronously when created. Empty default implementation.
This defines the initial actor behavior, it must return a partial function with the actor logic.
This defines the initial actor behavior, it must return a partial function with the actor logic.
Removes a member.
Removes a member.
Cluster member to remove.
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
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!
Adds the current message (the message that the actor received last) to the actor's stash.
Adds the current message (the message that the actor received last) to the actor's stash.
IllegalStateException
if the same message is stashed more than once
StashOverflowException
in case of a stash capacity violation
User overridable definition the strategy to use for supervising child actors.
User overridable definition the strategy to use for supervising child actors.
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
Prepends all messages in the stash to the mailbox, and then clears the stash.
Prepends all messages in the stash to the mailbox, and then clears the stash.
Messages from the stash are enqueued to the mailbox until the capacity of the
mailbox (if any) has been reached. In case a bounded mailbox overflows, a
MessageQueueAppendFailedException
is thrown.
The stash is guaranteed to be empty after calling unstashAll()
.
The
ClusterSingletonProxy
works together with the akka.contrib.pattern.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 stash the messages sent to the singleton and then unstash them when the singleton is finally available. The proxy mixes in the akka.actor.Stash trait, so it can be configured accordingly.
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.