akka.persistence

AbstractProcessor

Related Doc: package persistence

abstract class AbstractProcessor extends AbstractActor with Processor

Java API: compatible with lambda expressions

An actor that persists (journals) messages of type Persistent. Messages of other types are not persisted.

Example:

class MyProcessor extends AbstractProcessor {
  public MyProcessor() {
    receive(ReceiveBuilder.
      match(Persistent.class, p -> {
        Object payload = p.payload();
        Long sequenceNr = p.sequenceNr();
                // ...
      }).build()
    );
  }
}

// ...

ActorRef processor = context().actorOf(Props.create(MyProcessor.class), "myProcessor");

processor.tell(Persistent.create("foo"), null);
processor.tell("bar", null);

During start and restart, persistent messages are replayed to a processor so that it can recover internal state from these messages. New messages sent to a processor during recovery do not interfere with replayed messages, hence applications don't need to wait for a processor to complete its recovery.

Automated recovery can be turned off or customized by overriding the preStart and preRestart life cycle hooks. If automated recovery is turned off, an application can explicitly recover a processor by sending it a Recover message.

Persistent messages are assigned sequence numbers that are generated on a per-processor basis. A sequence starts at 1L and doesn't contain gaps unless a processor (logically) deletes a message.

During recovery, a processor internally buffers new messages until recovery completes, so that new messages do not interfere with replayed messages. This internal buffer (the processor stash) is isolated from the user stash inherited by akka.actor.Stash. Processor implementation classes can therefore use the user stash for stashing/unstashing both persistent and transient messages.

Processors can also store snapshots of internal state by calling saveSnapshot. During recovery, a saved snapshot is offered to the processor with a SnapshotOffer message, followed by replayed messages, if any, that are younger than the snapshot. Default is to offer the latest saved snapshot.

Annotations
@deprecated
Deprecated

(Since version 2.3.4) AbstractProcessor will be removed. Instead extend akka.persistence.AbstractPersistentActor and use it's persistAsync(command)(callback) method to get equivalent semantics.

Source
Processor.scala
See also

PersistentBatch

Recover

Processor

Linear Supertypes
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Inherited
  1. AbstractProcessor
  2. Processor
  3. ProcessorImpl
  4. Recovery
  5. StashFactory
  6. Stash
  7. RequiresMessageQueue
  8. UnrestrictedStash
  9. StashSupport
  10. Snapshotter
  11. AbstractActor
  12. Actor
  13. AnyRef
  14. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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  1. Public
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Instance Constructors

  1. new AbstractProcessor()

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 information
    This member is added by an implicit conversion from AbstractProcessor to any2stringadd[AbstractProcessor] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (AbstractProcessor, B)

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to ArrowAssoc[AbstractProcessor] 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

    Can be overridden to intercept calls to postRestart.

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

    Attributes
    protected[akka]
    Definition Classes
    Actor
  7. def aroundPostStop(): Unit

    INTERNAL API.

    INTERNAL API.

    Attributes
    protected[akka]
    Definition Classes
    ProcessorImpl → Actor
  8. def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit

    INTERNAL API.

    INTERNAL API.

    Attributes
    protected[akka]
    Definition Classes
    ProcessorImpl → Actor
  9. def aroundPreStart(): Unit

    INTERNAL API.

    INTERNAL API.

    Attributes
    protected[akka]
    Definition Classes
    ProcessorImpl → Actor
  10. def aroundReceive(receive: Receive, message: Any): Unit

    INTERNAL API.

    INTERNAL API.

    receive

    current behavior.

    Attributes
    protected[akka]
    Definition Classes
    RecoveryActor
  11. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  12. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  13. implicit val context: ActorContext

    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.

    Definition Classes
    Actor
  14. def deleteMessages(toSequenceNr: Long, permanent: Boolean): Unit

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

    Deletes all persistent messages with sequence numbers less than or equal toSequenceNr. If permanent is set to false, the persistent messages are marked as deleted in the journal, otherwise they permanently deleted from the journal.

    toSequenceNr

    upper sequence number bound of persistent messages to be deleted.

    permanent

    if false, the message is marked as deleted, otherwise it is permanently deleted.

    Definition Classes
    ProcessorImpl
  15. def deleteMessages(toSequenceNr: Long): Unit

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

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

    toSequenceNr

    upper sequence number bound of persistent messages to be deleted.

    Definition Classes
    ProcessorImpl
  16. def deleteSnapshot(sequenceNr: Long, timestamp: Long): Unit

    Deletes a snapshot identified by sequenceNr and timestamp.

    Deletes a snapshot identified by sequenceNr and timestamp.

    Definition Classes
    Snapshotter
  17. def deleteSnapshots(criteria: SnapshotSelectionCriteria): Unit

    Deletes all snapshots matching criteria.

    Deletes all snapshots matching criteria.

    Definition Classes
    Snapshotter
  18. def ensuring(cond: (AbstractProcessor) ⇒ Boolean, msg: ⇒ Any): AbstractProcessor

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to Ensuring[AbstractProcessor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  19. def ensuring(cond: (AbstractProcessor) ⇒ Boolean): AbstractProcessor

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to Ensuring[AbstractProcessor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  20. def ensuring(cond: Boolean, msg: ⇒ Any): AbstractProcessor

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to Ensuring[AbstractProcessor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  21. def ensuring(cond: Boolean): AbstractProcessor

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to Ensuring[AbstractProcessor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  22. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  23. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  24. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  25. def formatted(fmtstr: String): String

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to StringFormat[AbstractProcessor] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  26. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  27. def getContext(): AbstractActorContext

    Returns this AbstractActor's AbstractActorContext The AbstractActorContext is not thread safe so do not expose it outside of the AbstractActor.

    Returns this AbstractActor's AbstractActorContext The AbstractActorContext is not thread safe so do not expose it outside of the AbstractActor.

    Definition Classes
    AbstractActor
  28. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  29. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  30. def lastSequenceNr: Long

    Highest received sequence number so far or 0L if this actor hasn't received a persistent message yet.

    Highest received sequence number so far or 0L if this actor hasn't received a persistent message yet. Usually equal to the sequence number of currentPersistentMessage (unless a receiver implementation is about to re-order persistent messages using stash() and unstash()).

    Definition Classes
    Recovery
  31. def loadSnapshot(persistenceId: String, criteria: SnapshotSelectionCriteria, toSequenceNr: Long): Unit

    Definition Classes
    Snapshotter
  32. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  33. final def notify(): Unit

    Definition Classes
    AnyRef
  34. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  35. def persistenceId: String

    Persistence id.

    Persistence id. Defaults to this persistent-actors's path and can be overridden.

    Definition Classes
    ProcessorRecovery
  36. 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] )
  37. def postStop(): Unit

    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.

    Definition Classes
    UnrestrictedStashActor
  38. def preRestart(reason: Throwable, message: Option[Any]): Unit

    User-overridable callback.

    User-overridable callback. Called before a processor is restarted. Default implementation sends a Recover(lastSequenceNr) message to self if message is defined, Recover() otherwise.

    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
    ProcessorImpl → UnrestrictedStashActor
  39. def preRestartDefault(reason: Throwable, message: Option[Any]): Unit

    Calls preRestart and then super.preRestart().

    Calls preRestart and then super.preRestart(). If processor implementation classes want to opt out from stopping child actors, they should override this method and call preRestart only.

    Definition Classes
    ProcessorImpl
  40. def preStart(): Unit

    User-overridable callback.

    User-overridable callback. Called when a processor is started. Default implementation sends a Recover() to self.

    Definition Classes
    ProcessorImpl → Actor
    Annotations
    @throws( classOf[Exception] )
  41. def receive: actor.Actor.Receive

    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.

    Definition Classes
    AbstractActorActor
  42. def receive(receive: Receive): Unit

    Set up the initial receive behavior of the Actor.

    Set up the initial receive behavior of the Actor.

    receive

    The receive behavior.

    Attributes
    protected
    Definition Classes
    AbstractActor
    Annotations
    @throws( classOf[IllegalActorStateException] )
  43. def recoveryFinished: Boolean

    Returns true if this processor has successfully finished recovery.

    Returns true if this processor has successfully finished recovery.

    Definition Classes
    ProcessorImpl
  44. def recoveryRunning: Boolean

    Returns true if this processor is currently recovering.

    Returns true if this processor is currently recovering.

    Definition Classes
    ProcessorImpl
  45. def saveSnapshot(snapshot: Any): Unit

    Saves a snapshot of this snapshotter's state.

    Saves a snapshot of this snapshotter's state. If saving succeeds, this snapshotter will receive a SaveSnapshotSuccess message, otherwise a SaveSnapshotFailure message.

    Definition Classes
    Snapshotter
  46. 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
  47. 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
  48. def snapshotSequenceNr: Long

    Returns lastSequenceNr.

    Returns lastSequenceNr.

    Definition Classes
    RecoverySnapshotter
  49. def snapshotterId: String

    Returns persistenceId.

    Returns persistenceId.

    Definition Classes
    ProcessorImpl → Snapshotter
  50. def stash(): Unit

    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.

    Definition Classes
    StashSupport
    Exceptions thrown

    IllegalStateException if the same message is stashed more than once

    StashOverflowException in case of a stash capacity violation

  51. 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
  52. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  53. def toString(): String

    Definition Classes
    AnyRef → Any
  54. 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
    ProcessorImpl → Actor
  55. def unstashAll(): Unit

    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().

    Definition Classes
    StashSupport
  56. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  57. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  58. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  59. def [B](y: B): (AbstractProcessor, B)

    Implicit information
    This member is added by an implicit conversion from AbstractProcessor to ArrowAssoc[AbstractProcessor] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Deprecated Value Members

  1. implicit def currentPersistentMessage: Option[Persistent]

    Returns the current persistent message if there is any.

    Returns the current persistent message if there is any.

    Definition Classes
    Recovery
    Annotations
    @deprecated
    Deprecated

    (Since version 2.3.4) currentPersistentMessage will be removed, sequence number can be retrieved with lastSequenceNr.

  2. def deleteMessage(sequenceNr: Long, permanent: Boolean): Unit

    Deletes a persistent message identified by sequenceNr.

    Deletes a persistent message identified by sequenceNr. If permanent is set to false, the persistent message is marked as deleted in the journal, otherwise it is permanently deleted from the journal. A deleted message is not replayed during recovery. This method is usually called inside preRestartProcessor when a persistent message caused an exception. Processors that want to re-receive that persistent message during recovery should not call this method.

    sequenceNr

    sequence number of the persistent message to be deleted.

    permanent

    if false, the message is marked as deleted, otherwise it is permanently deleted.

    Definition Classes
    ProcessorImpl
    Annotations
    @deprecated
    Deprecated

    (Since version 2.3.4) deleteMessage(sequenceNr) will be removed. Instead, validate before persist, and use deleteMessages for pruning.

  3. def deleteMessage(sequenceNr: Long): Unit

    Marks a persistent message, identified by sequenceNr, as deleted.

    Marks a persistent message, identified by sequenceNr, as deleted. A message marked as deleted is not replayed during recovery. This method is usually called inside preRestartProcessor when a persistent message caused an exception. Processors that want to re-receive that persistent message during recovery should not call this method.

    sequenceNr

    sequence number of the persistent message to be deleted.

    Definition Classes
    ProcessorImpl
    Annotations
    @deprecated
    Deprecated

    (Since version 2.3.4) deleteMessage(sequenceNr) will be removed. Instead, validate before persist, and use deleteMessages for pruning.

  4. def getCurrentPersistentMessage: Persistent

    Java API: returns the current persistent message or null if there is none.

    Java API: returns the current persistent message or null if there is none.

    Definition Classes
    Recovery
    Annotations
    @deprecated
    Deprecated

    (Since version 2.3.4) getCurrentPersistentMessage will be removed, sequence number can be retrieved with lastSequenceNr.

  5. def processorId: String

    Processor id.

    Processor id. Defaults to this processor's path and can be overridden.

    Definition Classes
    ProcessorImpl → Recovery
    Annotations
    @deprecated
    Deprecated

    (Since version 2.3.4) Override persistenceId: String instead. Processor will be removed.

Inherited from Processor

Inherited from ProcessorImpl

Inherited from Recovery

Inherited from StashFactory

Inherited from Stash

Inherited from UnrestrictedStash

Inherited from StashSupport

Inherited from Snapshotter

Inherited from AbstractActor

Inherited from Actor

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from AbstractProcessor to any2stringadd[AbstractProcessor]

Inherited by implicit conversion StringFormat from AbstractProcessor to StringFormat[AbstractProcessor]

Inherited by implicit conversion Ensuring from AbstractProcessor to Ensuring[AbstractProcessor]

Inherited by implicit conversion ArrowAssoc from AbstractProcessor to ArrowAssoc[AbstractProcessor]

Ungrouped