BatchingSqlJournal(TConnection, TCommand) Class

BatchingSqlJournalTConnection, TCommand Class

An abstract journal used by PersistentActors to read/write events to a database. This implementation uses horizontal batching to recycle usage of the DbConnection and to optimize writes made to a database. Batching journal is not going to acquire a new DB connection on every request. Instead it will batch incoming requests and execute them only when a previous operation batch has been completed. This means that requests coming from many actors at the same time will be executed in one batch. Maximum number of batches executed at the same time is defined by MaxConcurrentOperations setting, while max allowed batch size is defined by MaxBatchSize setting. Batching journal also defines MaxBufferSize, which defines a maximum number of all requests stored at once in memory. Once that value is surpassed, journal will start to apply OnBufferOverflow(IJournalMessage) logic on each incoming requests, until a buffer gets freed again. This may be used for overflow strategies, request denials or backpressure.

Inheritance Hierarchy

SystemObject
  Akka.ActorActorBase
    Akka.Persistence.JournalWriteJournalBase
      Akka.Persistence.Sql.Common.JournalBatchingSqlJournalTConnection, TCommand
        Akka.Persistence.Sqlite.JournalBatchingSqliteJournal

Namespace: Akka.Persistence.Sql.Common.Journal
Assembly: Akka.Persistence.Sql.Common (in Akka.Persistence.Sql.Common.dll) Version: 1.0.0.0 (1.0.0.0)

Syntax

Copy

public abstract class BatchingSqlJournal<TConnection, TCommand> : WriteJournalBase
where TConnection : DbConnection
where TCommand : DbCommand

[<AbstractClassAttribute>]
type BatchingSqlJournal<'TConnection, 'TCommand when 'TConnection : DbConnection when 'TCommand : DbCommand> =  
    class
        inherit WriteJournalBase
    end

Type Parameters

TConnection: A concrete implementation of DbConnection for targeted database provider.
TCommand: A concrete implementation of DbCommand for targeted database provider.

The BatchingSqlJournalTConnection, TCommand type exposes the following members.

Constructors

	Name	Description
	BatchingSqlJournalTConnection, TCommand	Initializes a new instance of the BatchingSqlJournalTConnection, TCommand class.

Top

Properties

	Name	Description
	AllPersistenceIdsSql	SQL query executed as result of GetCurrentPersistenceIds request to journal. It's a part of persistence query protocol.
	ByPersistenceIdSql	SQL query executed as result of ReplayMessages request to journal. It's also part of persistence query protocol.
	ByTagSql	SQL query executed as result of ReplayTaggedMessages request to journal. It's a part of persistence query protocol.
	DeleteBatchSql	SQL query executed as result of DeleteMessagesTo request to journal.
	HasAllIdsSubscribers	Flag determining if current journal has any subscribers for GetCurrentPersistenceIds and PersistenceIdAdded messages.
	HasPersistenceIdSubscribers	Flag determining if current journal has any subscribers for EventAppended events.
	HasTagSubscribers	Flag determining if current journal has any subscribers for TaggedEventAppended events.
	HighestSequenceNrSql	SQL query executed as result of ReadHighestSequenceNr(String, TCommand) request to journal. Also used under some conditions, when storing metadata upon DeleteMessagesTo request.
	Initializers	A named collection of SQL statements to be executed once journal actor gets initialized and the AutoInitialize flag is set.
	InsertEventSql	SQL statement executed as result of WriteMessages request to journal.
	Self	Gets the self ActorRef (Inherited from ActorBase.)
	Sender	Gets the sending ActorRef of the current message (Inherited from ActorBase.)
	Setup	All configurable settings defined for a current batching journal.
	UpdateSequenceNrSql	SQL statement executed as result of writing metadata, which is a possible effect of DeleteMessagesTo request.

Top

Methods

	Name	Description
	AdaptFromJournal	TBD (Inherited from WriteJournalBase.)
	AdaptToJournal	TBD (Inherited from WriteJournalBase.)
	AddParameter	Helper method used to add a parameter to existing database command.
	AroundPostRestart	Can be overridden to intercept calls to `PostRestart`. Calls `PostRestart` by default. (Inherited from ActorBase.)
	AroundPostStop	Can be overridden to intercept calls to `PostStop`. Calls `PostStop` by default.. (Inherited from ActorBase.)
	AroundPreRestart	Can be overridden to intercept calls to `PreRestart`. Calls `PreRestart` by default. (Inherited from ActorBase.)
	AroundPreStart	Can be overridden to intercept calls to `PreStart`. Calls `PreStart` by default. (Inherited from ActorBase.)
	AroundReceive	TBD (Inherited from ActorBase.)
	BatchRequest	Tries to add incoming message to Buffer. Also checks if any DB connection has been released and next batch can be processed.
	Become	Changes the actor's command behavior and replaces the current receive handler with the specified handler. (Inherited from ActorBase.)
	BecomeStacked	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.)
	CreateConnection	Creates a new database connection from a given connectionString.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	HandleDeleteMessagesTo
	HandleReplayMessages
	HandleReplayTaggedMessages
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	NotifyNewPersistenceIdAdded
	OnBufferOverflow	Method called, once given request couldn't be added to Buffer due to buffer overflow. Overflow is controlled by max buffer size and can be set using MaxBufferSize setting.
	PostRestart	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.)
	PostStop	User overridable callback. Is called asynchronously after 'actor.stop()' is invoked. Empty default implementation. (Inherited from ActorBase.)
	PreparePersistentBatch	TBD (Inherited from WriteJournalBase.)
	PreRestart	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.)
	PreStart	TBD (Overrides ActorBasePreStart.)
	ReadEvent	Returns a persistent representation of an event read from a current row in the database.
	ReadHighestSequenceNr
	Receive	TBD (Overrides ActorBaseReceive(Object).)
	SetReceiveTimeout	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.)
	SupervisorStrategy	TBD (Inherited from ActorBase.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	UnbecomeStacked	Reverts the Actor behavior to the previous one on the behavior stack. (Inherited from ActorBase.)
	Unhandled	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.)
	WriteEvent	Perform write of persistent event with specified tags into database using given command.

Top

Fields

	Name	Description
	Buffer	Buffer for requests that are waiting to be served when next DB connection will be released. This object access is NOT thread safe.
	CanPublish	Flag determining if incoming journal requests should be published in current actor system event stream. Useful mostly for tests.
	IsDeletedIndex	Default index of IsDeleted column get from ByPersistenceIdSql query.
	Log	Logging adapter for current journal actor .
	ManifestIndex	Default index of Manifest column get from ByPersistenceIdSql query.
	OrderingIndex	Default index of tags column get from ByTagSql query.
	PayloadIndex	Default index of Payload column get from ByPersistenceIdSql query.
	PersistenceIdIndex	Default index of PersistenceId column get from ByPersistenceIdSql query.
	SequenceNrIndex	Default index of SequenceNr column get from ByPersistenceIdSql query.

Top

Extension Methods

	Name	Description
	AsInstanceOfT	TBD (Defined by Extensions.)
	Match	Overloaded. Matches the specified target. (Defined by PatternMatch.)
	MatchT	Overloaded. Matches the specified target and return a result of target processing. (Defined by PatternMatch.)

Top

Reference

Akka.Persistence.Sql.Common.Journal Namespace