t

akka.persistence.journal

AsyncWriteJournal

trait AsyncWriteJournal extends Actor with WriteJournalBase with AsyncRecovery

Abstract journal, optimized for asynchronous, non-blocking writes.

Source
AsyncWriteJournal.scala
Linear Supertypes
AsyncRecovery, WriteJournalBase, Actor, AnyRef, Any
Type Hierarchy
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Inherited
  1. AsyncWriteJournal
  2. AsyncRecovery
  3. WriteJournalBase
  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

Type Members

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

Abstract Value Members

  1. abstract def asyncDeleteMessagesTo(persistenceId: String, toSequenceNr: Long): Future[Unit]

    Plugin API: asynchronously deletes all persistent messages up to toSequenceNr (inclusive).

    Plugin API: asynchronously deletes all persistent messages up to toSequenceNr (inclusive).

    This call is protected with a circuit-breaker. Message deletion doesn't affect the highest sequence number of messages, journal must maintain the highest sequence number and never decrease it.

  2. abstract def asyncReadHighestSequenceNr(persistenceId: String, fromSequenceNr: Long): Future[Long]

    Plugin API: asynchronously reads the highest stored sequence number for the given persistenceId.

    Plugin API: asynchronously reads the highest stored sequence number for the given persistenceId. The persistent actor will use the highest sequence number after recovery as the starting point when persisting new events. This sequence number is also used as toSequenceNr in subsequent call to #asyncReplayMessages unless the user has specified a lower toSequenceNr. Journal must maintain the highest sequence number and never decrease it.

    This call is protected with a circuit-breaker.

    Please also note that requests for the highest sequence number may be made concurrently to writes executing for the same persistenceId, in particular it is possible that a restarting actor tries to recover before its outstanding writes have completed.

    persistenceId

    persistent actor id.

    fromSequenceNr

    hint where to start searching for the highest sequence number. When a persistent actor is recovering this fromSequenceNr will be the sequence number of the used snapshot or 0L if no snapshot is used.

    Definition Classes
    AsyncRecovery
  3. abstract def asyncReplayMessages(persistenceId: String, fromSequenceNr: Long, toSequenceNr: Long, max: Long)(recoveryCallback: (PersistentRepr) => Unit): Future[Unit]

    Plugin API: asynchronously replays persistent messages.

    Plugin API: asynchronously replays persistent messages. Implementations replay a message by calling replayCallback. The returned future must be completed when all messages (matching the sequence number bounds) have been replayed. The future must be completed with a failure if any of the persistent messages could not be replayed.

    The replayCallback must also be called with messages that have been marked as deleted. In this case a replayed message's deleted method must return true.

    The toSequenceNr is the lowest of what was returned by #asyncReadHighestSequenceNr and what the user specified as recovery akka.persistence.Recovery parameter. This does imply that this call is always preceded by reading the highest sequence number for the given persistenceId.

    This call is NOT protected with a circuit-breaker because it may take long time to replay all events. The plugin implementation itself must protect against an unresponsive backend store and make sure that the returned Future is completed with success or failure within reasonable time. It is not allowed to ignore completing the future.

    persistenceId

    persistent actor id.

    fromSequenceNr

    sequence number where replay should start (inclusive).

    toSequenceNr

    sequence number where replay should end (inclusive).

    max

    maximum number of messages to be replayed.

    recoveryCallback

    called to replay a single message. Can be called from any thread.

    Definition Classes
    AsyncRecovery
    See also

    AsyncWriteJournal

  4. abstract def asyncWriteMessages(messages: Seq[AtomicWrite]): Future[Seq[Try[Unit]]]

    Plugin API: asynchronously writes a batch (Seq) of persistent messages to the journal.

    Plugin API: asynchronously writes a batch (Seq) of persistent messages to the journal.

    The batch is only for performance reasons, i.e. all messages don't have to be written atomically. Higher throughput can typically be achieved by using batch inserts of many records compared to inserting records one-by-one, but this aspect depends on the underlying data store and a journal implementation can implement it as efficient as possible. Journals should aim to persist events in-order for a given persistenceId as otherwise in case of a failure, the persistent state may be end up being inconsistent.

    Each AtomicWrite message contains the single PersistentRepr that corresponds to the event that was passed to the persist method of the PersistentActor, or it contains several PersistentRepr that corresponds to the events that were passed to the persistAll method of the PersistentActor. All PersistentRepr of the AtomicWrite must be written to the data store atomically, i.e. all or none must be stored. If the journal (data store) cannot support atomic writes of multiple events it should reject such writes with a Try Failure with an UnsupportedOperationException describing the issue. This limitation should also be documented by the journal plugin.

    If there are failures when storing any of the messages in the batch the returned Future must be completed with failure. The Future must only be completed with success when all messages in the batch have been confirmed to be stored successfully, i.e. they will be readable, and visible, in a subsequent replay. If there is uncertainty about if the messages were stored or not the Future must be completed with failure.

    Data store connection problems must be signaled by completing the Future with failure.

    The journal can also signal that it rejects individual messages (AtomicWrite) by the returned immutable.Seq[Try[Unit]]. It is possible but not mandatory to reduce number of allocations by returning Future.successful(Nil) for the happy path, i.e. when no messages are rejected. Otherwise the returned Seq must have as many elements as the input messages Seq. Each Try element signals if the corresponding AtomicWrite is rejected or not, with an exception describing the problem. Rejecting a message means it was not stored, i.e. it must not be included in a later replay. Rejecting a message is typically done before attempting to store it, e.g. because of serialization error.

    Data store connection problems must not be signaled as rejections.

    It is possible but not mandatory to reduce number of allocations by returning Future.successful(Nil) for the happy path, i.e. when no messages are rejected.

    Calls to this method are serialized by the enclosing journal actor. If you spawn work in asynchronous tasks it is alright that they complete the futures in any order, but the actual writes for a specific persistenceId should be serialized to avoid issues such as events of a later write are visible to consumers (query side, or replay) before the events of an earlier write are visible. A PersistentActor will not send a new WriteMessages request before the previous one has been completed.

    Please note that the sender field of the contained PersistentRepr objects has been nulled out (i.e. set to ActorRef.noSender) in order to not use space in the journal for a sender reference that will likely be obsolete during replay.

    Please also note that requests for the highest sequence number may be made concurrently to this call executing for the same persistenceId, in particular it is possible that a restarting actor tries to recover before its outstanding writes have completed. In the latter case it is highly desirable to defer reading the highest sequence number until all outstanding writes have completed, otherwise the PersistentActor may reuse sequence numbers.

    This call is protected with a circuit-breaker.

Concrete 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 AsyncWriteJournal toany2stringadd[AsyncWriteJournal] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (AsyncWriteJournal, B)
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toArrowAssoc[AsyncWriteJournal] 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[akka]
    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[akka]
    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[akka]
    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[akka]
    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[akka]
    Definition Classes
    Actor
    Annotations
    @InternalApi()
  11. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  12. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native() @HotSpotIntrinsicCandidate()
  13. 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!

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

    Definition Classes
    Actor
  14. def ensuring(cond: (AsyncWriteJournal) => Boolean, msg: => Any): AsyncWriteJournal
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toEnsuring[AsyncWriteJournal] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  15. def ensuring(cond: (AsyncWriteJournal) => Boolean): AsyncWriteJournal
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toEnsuring[AsyncWriteJournal] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  16. def ensuring(cond: Boolean, msg: => Any): AsyncWriteJournal
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toEnsuring[AsyncWriteJournal] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  17. def ensuring(cond: Boolean): AsyncWriteJournal
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toEnsuring[AsyncWriteJournal] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  18. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  19. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  20. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  21. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  22. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  23. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  24. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  25. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  26. val persistence: Persistence
    Definition Classes
    WriteJournalBase
  27. 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])
  28. def postStop(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    Actor
    Annotations
    @throws(classOf[Exception])
  29. 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])
  30. 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
    Actor
    Annotations
    @throws(classOf[Exception])
  31. def preparePersistentBatch(rb: Seq[PersistentEnvelope]): Seq[AtomicWrite]
    Attributes
    protected
    Definition Classes
    WriteJournalBase
  32. final 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
    AsyncWriteJournalActor
  33. def receivePluginInternal: actor.Actor.Receive

    Plugin API

    Plugin API

    Allows plugin implementers to use f pipeTo self and handle additional messages for implementing advanced features

  34. final val receiveWriteJournal: actor.Actor.Receive
  35. 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
  36. 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
  37. 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
  38. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  39. def toString(): String
    Definition Classes
    AnyRef → Any
  40. 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
    Actor
  41. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  42. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  43. 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
  2. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toStringFormat[AsyncWriteJournal] 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): (AsyncWriteJournal, B)
    Implicit
    This member is added by an implicit conversion from AsyncWriteJournal toArrowAssoc[AsyncWriteJournal] 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 AsyncRecovery

Inherited from WriteJournalBase

Inherited from Actor

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromAsyncWriteJournal to any2stringadd[AsyncWriteJournal]

Inherited by implicit conversion StringFormat fromAsyncWriteJournal to StringFormat[AsyncWriteJournal]

Inherited by implicit conversion Ensuring fromAsyncWriteJournal to Ensuring[AsyncWriteJournal]

Inherited by implicit conversion ArrowAssoc fromAsyncWriteJournal to ArrowAssoc[AsyncWriteJournal]

Ungrouped