raboof/pekko
1
0
Fork 0
Code Issues Pull requests Projects Releases 6 Packages Wiki Activity Actions 10

!clu #3617 API improvements related to CurrentClusterState

Browse source 
* Getter for CurrentClusterState in Cluster extension, updated via
  ClusterReadView
* Remove lazy init of readView. Otherwise the cluster.state will be
  empty on first access, wich is probably surprising
* Subscribe to several cluster event types at once, to ensure *one*
  CurrentClusterEvent followed by change events
* Deprecate publishCurrentClusterState, was a bad idea, use sendCurrentClusterState
  instead
* Possibility to subscribe with InitialStateAsEvents to receive events corresponding
  to CurrentClusterState
* CurrentClusterState not a ClusterDomainEvent, ticket #3614
This commit is contained in:
Patrik Nordwall 2014-01-08 14:14:48 +01:00
parent bfbee94fec
commit 2e5193347e
19 changed files with 342 additions and 99 deletions
Download patch file Download diff file Expand all files Collapse all files

50
akka-cluster/src/main/scala/akka/cluster/Cluster.scala
View file

@ -29,6 +29,7 @@ import com.typesafe.config.Config
import akka.event.LoggingAdapter
import java.util.concurrent.ThreadFactory
import scala.util.control.NonFatal
import scala.annotation.varargs
/**
* Cluster Extension Id and factory for creating Cluster extension.
@ -178,13 +179,7 @@ class Cluster(val system: ExtendedActorSystem) extends Extension {
}
}
@volatile
private var readViewStarted = false
private[cluster] lazy val readView: ClusterReadView = {
val readView = new ClusterReadView(this)
readViewStarted = true
readView
}
private[cluster] val readView: ClusterReadView = new ClusterReadView(this)
system.registerOnTermination(shutdown())
@ -207,15 +202,38 @@ class Cluster(val system: ExtendedActorSystem) extends Extension {
def isTerminated: Boolean = _isTerminated.get
/**
* Subscribe to cluster domain events.
* The `to` Class can be [[akka.cluster.ClusterEvent.ClusterDomainEvent]]
* or subclass.
* Current snapshot state of the cluster.
*/
def state: CurrentClusterState = readView.state
/**
* Subscribe to one or more cluster domain events.
* The `to` classes can be [[akka.cluster.ClusterEvent.ClusterDomainEvent]]
* or subclasses.
*
* A snapshot of [[akka.cluster.ClusterEvent.CurrentClusterState]]
* will be sent to the subscriber as the first event.
* will be sent to the subscriber as the first message.
*/
def subscribe(subscriber: ActorRef, to: Class[_]): Unit =
clusterCore ! InternalClusterAction.Subscribe(subscriber, to)
@varargs def subscribe(subscriber: ActorRef, to: Class[_]*): Unit =
clusterCore ! InternalClusterAction.Subscribe(subscriber, initialStateMode = InitialStateAsSnapshot, to.toSet)
/**
* Subscribe to one or more cluster domain events.
* The `to` classes can be [[akka.cluster.ClusterEvent.ClusterDomainEvent]]
* or subclasses.
*
* If `initialStateMode` is [[ClusterEvent.InitialStateAsEvents]] the events corresponding
* to the current state will be sent to the subscriber to mimic what you would
* have seen if you were listening to the events when they occurred in the past.
*
* If `initialStateMode` is [[ClusterEvent.InitialStateAsSnapshot]] a snapshot of
* [[akka.cluster.ClusterEvent.CurrentClusterState]] will be sent to the subscriber as the
* first message.
*
* Note that for large clusters it is more efficient to use `InitialStateAsSnapshot`.
*/
@varargs def subscribe(subscriber: ActorRef, initialStateMode: SubscriptionInitialStateMode, to: Class[_]*): Unit =
clusterCore ! InternalClusterAction.Subscribe(subscriber, initialStateMode, to.toSet)
/**
* Unsubscribe to all cluster domain events.
@ -237,13 +255,15 @@ class Cluster(val system: ExtendedActorSystem) extends Extension {
* If you want this to happen periodically you need to schedule a call to
* this method yourself.
*/
@deprecated("Use sendCurrentClusterState instead of publishCurrentClusterState", "2.3")
def publishCurrentClusterState(): Unit =
clusterCore ! InternalClusterAction.PublishCurrentClusterState(None)
/**
* Publish current (full) state of the cluster to the specified
* receiver. If you want this to happen periodically you need to schedule
* a call to this method yourself.
* a call to this method yourself. Note that you can also retrieve the current
* state with [[#state]].
*/
def sendCurrentClusterState(receiver: ActorRef): Unit =
clusterCore ! InternalClusterAction.PublishCurrentClusterState(Some(receiver))
@ -333,7 +353,7 @@ class Cluster(val system: ExtendedActorSystem) extends Extension {
logInfo("Shutting down...")
system.stop(clusterDaemons)
if (readViewStarted) readView.close()
readView.close()
closeScheduler()