PersistentShardCoordinator

Defer the handler execution until all pending handlers have been executed. It is guaranteed that no new commands will be received by a persistent actor between a call to defer and the execution of its handler. Allows to define logic within the actor, which will respect the invocation-order-guarantee in respect to persistAsync or persist calls. That is, if persistAsync or persist was invoked before defer, the corresponding handlers will be invoked in the same order as they were registered in.

This call will NOT result in event being persisted, use persist or persistAsync instead if the given event should possible to replay.

If there are no pending persist handler calls, the handler will be called immediately.

If persistence of an earlier event fails, the persistent actor will stop, and the handler will not be run.

Defer the handler execution until all pending handlers have been executed. Allows to define logic within the actor, which will respect the invocation-order-guarantee in respect to persistAsync or persist calls. That is, if persistAsync or persist was invoked before deferAsync, the corresponding handlers will be invoked in the same order as they were registered in.

This call will NOT result in event being persisted, use persist or persistAsync instead if the given event should possible to replay.

If there are no pending persist handler calls, the handler will be called immediately.

If persistence of an earlier event fails, the persistent actor will stop, and the handler will not be run.

Permanently deletes all persistent messages with sequence numbers less than or equal toSequenceNr.

If the delete is successful a DeleteMessagesSuccess will be sent to the actor. If the delete fails a DeleteMessagesFailure will be sent to the actor.

The given toSequenceNr must be less than or equal to Eventsourced#lastSequenceNr, otherwise DeleteMessagesFailure is sent to the actor without performing the delete. All persistent messages may be deleted without specifying the actual sequence number by using Long.MaxValue as the toSequenceNr.

Deletes the snapshot identified by sequenceNr.

The PersistentActor will be notified about the status of the deletion via an DeleteSnapshotSuccess or DeleteSnapshotFailure message.

Deletes all snapshots matching criteria.

The PersistentActor will be notified about the status of the deletion via an DeleteSnapshotsSuccess or DeleteSnapshotsFailure message.

The returned StashOverflowStrategy object determines how to handle the message failed to stash when the internal Stash capacity exceeded.

Highest received sequence number so far or 0L if this actor hasn't replayed or stored any persistent events yet.

Instructs the snapshot store to load the specified snapshot and send it via an SnapshotOffer to the running PersistentActor.

Asynchronously persists event. On successful persistence, handler is called with the persisted event. It is guaranteed that no new commands will be received by a persistent actor between a call to persist and the execution of its handler. This also holds for multiple persist calls per received command. Internally, this is achieved by stashing new commands and unstashing them when the event has been persisted and handled. The stash used for that is an internal stash which doesn't interfere with the inherited user stash.

An event handler may close over persistent actor state and modify it. The sender of a persisted event is the sender of the corresponding command. This means that one can reply to a command sender within an event handler.

Within an event handler, applications usually update persistent actor state using persisted event data, notify listeners and reply to command senders.

If persistence of an event fails, onPersistFailure will be invoked and the actor will unconditionally be stopped. The reason that it cannot resume when persist fails is that it is unknown if the event was actually persisted or not, and therefore it is in an inconsistent state. Restarting on persistent failures will most likely fail anyway, since the journal is probably unavailable. It is better to stop the actor and after a back-off timeout start it again.

Asynchronously persists events in specified order. This is equivalent to calling persist[A](event: A)(handler: A => Unit) multiple times with the same handler, except that events are persisted atomically with this method.

Asynchronously persists events in specified order. This is equivalent to calling persistAsync[A](event: A)(handler: A => Unit) multiple times with the same handler, except that events are persisted atomically with this method.

Asynchronously persists event. On successful persistence, handler is called with the persisted event.

Unlike persist the persistent actor will continue to receive incoming commands between the call to persist and executing it's handler. This asynchronous, non-stashing, version of of persist should be used when you favor throughput over the "command-2 only processed after command-1 effects' have been applied" guarantee, which is provided by the plain persist method.

An event handler may close over persistent actor state and modify it. The sender of a persisted event is the sender of the corresponding command. This means that one can reply to a command sender within an event handler.

If persistence of an event fails, onPersistFailure will be invoked and the actor will unconditionally be stopped. The reason that it cannot resume when persist fails is that it is unknown if the event was actually persisted or not, and therefore it is in an inconsistent state. Restarting on persistent failures will most likely fail anyway, since the journal is probably unavailable. It is better to stop the actor and after a back-off timeout start it again.

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

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. Prepends all messages in the stash to the mailbox, clears the stash, stops all children and invokes the postStop() callback.

Called when the persistent actor is started for the first time. The returned Recovery object defines how the Actor will recover its persistent state before handling the first incoming message.

To skip recovery completely return Recovery.none.

Returns true if this persistent actor has successfully finished recovery.

Returns true if this persistent actor is currently recovering.

Saves a snapshot of this snapshotter's state.

The PersistentActor will be notified about the success or failure of this via an SaveSnapshotSuccess or SaveSnapshotFailure 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!

Returns lastSequenceNr.

Returns persistenceId.

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

Start and cancel timers via the enclosed TimerScheduler.

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.

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

Can be used to send messages to itself:

self ! message