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

68
akka-cluster/src/main/scala/akka/cluster/ClusterEvent.scala
View file

@ -20,6 +20,31 @@ import akka.dispatch.{ UnboundedMessageQueueSemantics, RequiresMessageQueue }
* }}}
*/
object ClusterEvent {
sealed abstract class SubscriptionInitialStateMode
/**
* When using this subscription mode a snapshot of
* [[akka.cluster.ClusterEvent.CurrentClusterState]] will be sent to the
* subscriber as the first message.
*/
case object InitialStateAsSnapshot extends SubscriptionInitialStateMode
/**
* When using this subscription mode 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.
*/
case object InitialStateAsEvents extends SubscriptionInitialStateMode
/**
* Java API
*/
def initialStateAsSnapshot = InitialStateAsSnapshot
/**
* Java API
*/
def initialStateAsEvents = InitialStateAsEvents
/**
* Marker interface for cluster domain events.
*/
@ -33,7 +58,7 @@ object ClusterEvent {
unreachable: Set[Member] = Set.empty,
seenBy: Set[Address] = Set.empty,
leader: Option[Address] = None,
roleLeaderMap: Map[String, Option[Address]] = Map.empty) extends ClusterDomainEvent {
roleLeaderMap: Map[String, Option[Address]] = Map.empty) {
/**
* Java API: get current member list.
@ -102,7 +127,8 @@ object ClusterEvent {
}
/**
* Member status changed to Exiting.
* Member status changed to [[MemberStatus.Exiting]] and will be removed
* when all members have seen the `Exiting` status.
*/
case class MemberExited(member: Member) extends MemberEvent {
if (member.status != Exiting) throw new IllegalArgumentException("Expected Exiting status, got: " + member)
@ -305,7 +331,7 @@ private[cluster] final class ClusterDomainEventPublisher extends Actor with Acto
case PublishChanges(newGossip) ⇒ publishChanges(newGossip)
case currentStats: CurrentInternalStats ⇒ publishInternalStats(currentStats)
case PublishCurrentClusterState(receiver) ⇒ publishCurrentClusterState(receiver)
case Subscribe(subscriber, to) ⇒ subscribe(subscriber, to)
case Subscribe(subscriber, initMode, to) ⇒ subscribe(subscriber, initMode, to)
case Unsubscribe(subscriber, to) ⇒ unsubscribe(subscriber, to)
case PublishEvent(event) ⇒ publish(event)
}
@ -314,7 +340,7 @@ private[cluster] final class ClusterDomainEventPublisher extends Actor with Acto
/**
* The current snapshot state corresponding to latest gossip
* to mimic what you would have seen if you where listening to the events.
* to mimic what you would have seen if you were listening to the events.
*/
def publishCurrentClusterState(receiver: Option[ActorRef]): Unit = {
val state = CurrentClusterState(
@ -329,9 +355,19 @@ private[cluster] final class ClusterDomainEventPublisher extends Actor with Acto
}
}
def subscribe(subscriber: ActorRef, to: Class[_]): Unit = {
publishCurrentClusterState(Some(subscriber))
eventStream.subscribe(subscriber, to)
def subscribe(subscriber: ActorRef, initMode: SubscriptionInitialStateMode, to: Set[Class[_]]): Unit = {
initMode match {
case InitialStateAsEvents ⇒
def pub(event: AnyRef): Unit = {
if (to.exists(_.isAssignableFrom(event.getClass)))
subscriber ! event
}
publishDiff(Gossip.empty, latestGossip, pub)
case InitialStateAsSnapshot ⇒
publishCurrentClusterState(Some(subscriber))
}
to foreach { eventStream.subscribe(subscriber, _) }
}
def unsubscribe(subscriber: ActorRef, to: Option[Class[_]]): Unit = to match {
@ -343,14 +379,18 @@ private[cluster] final class ClusterDomainEventPublisher extends Actor with Acto
val oldGossip = latestGossip
// keep the latestGossip to be sent to new subscribers
latestGossip = newGossip
diffUnreachable(oldGossip, newGossip) foreach publish
diffReachable(oldGossip, newGossip) foreach publish
diffMemberEvents(oldGossip, newGossip) foreach publish
diffLeader(oldGossip, newGossip) foreach publish
diffRolesLeader(oldGossip, newGossip) foreach publish
publishDiff(oldGossip, newGossip, publish)
}
def publishDiff(oldGossip: Gossip, newGossip: Gossip, pub: AnyRef ⇒ Unit): Unit = {
diffMemberEvents(oldGossip, newGossip) foreach pub
diffUnreachable(oldGossip, newGossip) foreach pub
diffReachable(oldGossip, newGossip) foreach pub
diffLeader(oldGossip, newGossip) foreach pub
diffRolesLeader(oldGossip, newGossip) foreach pub
// publish internal SeenState for testing purposes
diffSeen(oldGossip, newGossip) foreach publish
diffReachability(oldGossip, newGossip) foreach publish
diffSeen(oldGossip, newGossip) foreach pub
diffReachability(oldGossip, newGossip) foreach pub
}
def publishInternalStats(currentStats: CurrentInternalStats): Unit = publish(currentStats)