=sam #3843 Use ClusterSingletonProxy in cluster samples

akka-docs/rst/java/cluster-usage.rst

@@ -519,14 +519,14 @@ in the contrib module. The ``ClusterSingletonManager`` is started on each node.
 .. includecode:: ../../../akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsSampleOneMasterMain.java#create-singleton-manager
 
 We also need an actor on each node that keeps track of where current single master exists and
-delegates jobs to the ``StatsService``.
+delegates jobs to the ``StatsService``. That is provided by the ``ClusterSingletonProxy``.
 
-.. includecode:: ../../../akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsFacade.java#facade
+.. includecode:: ../../../akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsSampleOneMasterMain.java#singleton-proxy
 
-The ``StatsFacade`` receives text from users and delegates to the current ``StatsService``, the single
+The ``ClusterSingletonProxy`` receives text from users and delegates to the current ``StatsService``, the single
 master. It listens to cluster events to lookup the ``StatsService`` on the oldest node.
 
-All nodes start ``StatsFacade`` and the ``ClusterSingletonManager``. The router is now configured like this:
+All nodes start ``ClusterSingletonProxy`` and the ``ClusterSingletonManager``. The router is now configured like this:
 
 .. includecode:: ../../../akka-samples/akka-sample-cluster-java/src/main/resources/stats2.conf#config-router-deploy
 

akka-docs/rst/scala/cluster-usage.rst

@@ -514,14 +514,14 @@ in the contrib module. The ``ClusterSingletonManager`` is started on each node.
 .. includecode:: ../../../akka-samples/akka-sample-cluster-scala/src/main/scala/sample/cluster/stats/StatsSampleOneMaster.scala#create-singleton-manager
 
 We also need an actor on each node that keeps track of where current single master exists and
-delegates jobs to the ``StatsService``.
+delegates jobs to the ``StatsService``.  That is provided by the ``ClusterSingletonProxy``.
 
-.. includecode:: ../../../akka-samples/akka-sample-cluster-scala/src/main/scala/sample/cluster/stats/StatsFacade.scala#facade
+.. includecode:: ../../../akka-samples/akka-sample-cluster-scala/src/main/scala/sample/cluster/stats/StatsSampleOneMaster.scala#singleton-proxy
 
-The ``StatsFacade`` receives text from users and delegates to the current ``StatsService``, the single
+The ``ClusterSingletonProxy`` receives text from users and delegates to the current ``StatsService``, the single
 master. It listens to cluster events to lookup the ``StatsService`` on the oldest node.
 
-All nodes start ``StatsFacade`` and the ``ClusterSingletonManager``. The router is now configured like this:
+All nodes start ``ClusterSingletonProxy`` and the ``ClusterSingletonManager``. The router is now configured like this:
 
 .. includecode:: ../../../akka-samples/akka-sample-cluster-scala/src/main/resources/stats2.conf#config-router-deploy
 

akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsFacade.java

@@ -1,95 +0,0 @@
-package sample.cluster.stats;
-
-import java.util.ArrayList;
-import java.util.Comparator;
-import java.util.List;
-import java.util.SortedSet;
-import java.util.TreeSet;
-
-import sample.cluster.stats.StatsMessages.JobFailed;
-import sample.cluster.stats.StatsMessages.StatsJob;
-import akka.actor.ActorSelection;
-import akka.actor.UntypedActor;
-import akka.cluster.Cluster;
-import akka.cluster.ClusterEvent.CurrentClusterState;
-import akka.cluster.ClusterEvent.MemberEvent;
-import akka.cluster.ClusterEvent.MemberUp;
-import akka.cluster.ClusterEvent.MemberRemoved;
-import akka.cluster.Member;
-import akka.event.Logging;
-import akka.event.LoggingAdapter;
-
-//#facade
-public class StatsFacade extends UntypedActor {
-
-  final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
-  final Cluster cluster = Cluster.get(getContext().system());
-
-  final Comparator<Member> ageComparator = new Comparator<Member>() {
-    public int compare(Member a, Member b) {
-      if (a.isOlderThan(b))
-        return -1;
-      else if (b.isOlderThan(a))
-        return 1;
-      else
-        return 0;
-    }
-  };
-  final SortedSet<Member> membersByAge = new TreeSet<Member>(ageComparator);
-
-  //subscribe to cluster changes
-  @Override
-  public void preStart() {
-    cluster.subscribe(getSelf(), MemberEvent.class);
-  }
-
-  //re-subscribe when restart
-  @Override
-  public void postStop() {
-    cluster.unsubscribe(getSelf());
-  }
-
-  @Override
-  public void onReceive(Object message) {
-    if (message instanceof StatsJob && membersByAge.isEmpty()) {
-      getSender().tell(new JobFailed("Service unavailable, try again later"),
-          getSelf());
-
-    } else if (message instanceof StatsJob) {
-      currentMaster().tell(message, getSender());
-
-    } else if (message instanceof CurrentClusterState) {
-      CurrentClusterState state = (CurrentClusterState) message;
-      List<Member> members = new ArrayList<Member>();
-      for (Member m : state.getMembers()) {
-        if (m.hasRole("compute"))
-          members.add(m);
-      }
-      membersByAge.clear();
-      membersByAge.addAll(members);
-
-    } else if (message instanceof MemberUp) {
-      Member m = ((MemberUp) message).member();
-      if (m.hasRole("compute"))
-        membersByAge.add(m);
-
-    } else if (message instanceof MemberRemoved) {
-      Member m = ((MemberRemoved) message).member();
-      if (m.hasRole("compute"))
-        membersByAge.remove(m);
-
-    } else if (message instanceof MemberEvent) {
-      // not interesting
-
-    } else {
-      unhandled(message);
-    }
-  }
-
-  ActorSelection currentMaster() {
-    return getContext().actorSelection(
-        membersByAge.first().address() + "/user/singleton/statsService");
-  }
-
-}
-//#facade

akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsSampleOneMasterClientMain.java

@@ -11,7 +11,7 @@ public class StatsSampleOneMasterClientMain {
     // note that client is not a compute node, role not defined
     ActorSystem system = ActorSystem.create("ClusterSystem",
         ConfigFactory.load("stats2"));
-    system.actorOf(Props.create(StatsSampleClient.class, "/user/statsFacade"),
+    system.actorOf(Props.create(StatsSampleClient.class, "/user/statsServiceProxy"),
         "client");
 
   }

akka-samples/akka-sample-cluster-java/src/main/java/sample/cluster/stats/StatsSampleOneMasterMain.java

@@ -7,6 +7,7 @@ import akka.actor.ActorSystem;
 import akka.actor.PoisonPill;
 import akka.actor.Props;
 import akka.contrib.pattern.ClusterSingletonManager;
+import akka.contrib.pattern.ClusterSingletonProxy;
 
 public class StatsSampleOneMasterMain {
 
@@ -36,7 +37,10 @@ public class StatsSampleOneMasterMain {
           PoisonPill.getInstance(), "compute"), "singleton");
       //#create-singleton-manager
 
-      system.actorOf(Props.create(StatsFacade.class), "statsFacade");
+      //#singleton-proxy
+      system.actorOf(ClusterSingletonProxy.defaultProps("/user/singleton/statsService",
+        "compute"), "statsServiceProxy");
+      //#singleton-proxy
     }
 
   }

akka-samples/akka-sample-cluster-java/src/multi-jvm/scala/sample/cluster/stats/StatsSampleSingleMasterSpec.scala

@@ -15,6 +15,7 @@ import akka.cluster.MemberStatus
 import akka.cluster.ClusterEvent.CurrentClusterState
 import akka.cluster.ClusterEvent.MemberUp
 import akka.contrib.pattern.ClusterSingletonManager
+import akka.contrib.pattern.ClusterSingletonProxy
 import akka.remote.testkit.MultiNodeConfig
 import akka.remote.testkit.MultiNodeSpec
 import akka.testkit.ImplicitSender
@@ -91,18 +92,19 @@ abstract class StatsSampleSingleMasterSpec extends MultiNodeSpec(StatsSampleSing
         terminationMessage = PoisonPill,
         role = null), name = "singleton")
 
-      system.actorOf(Props[StatsFacade], "statsFacade")
+      system.actorOf(ClusterSingletonProxy.defaultProps("/user/singleton/statsService",
+        "compute"), "statsServiceProxy");
 
       testConductor.enter("all-up")
     }
 
-    "show usage of the statsFacade" in within(40 seconds) {
+    "show usage of the statsServiceProxy" in within(40 seconds) {
-      val facade = system.actorSelection(RootActorPath(node(third).address) / "user" / "statsFacade")
+      val proxy = system.actorSelection(RootActorPath(node(third).address) / "user" / "statsServiceProxy")
 
       // eventually the service should be ok,
       // service and worker nodes might not be up yet
       awaitAssert {
-        facade ! new StatsJob("this is the text that will be analyzed")
+        proxy ! new StatsJob("this is the text that will be analyzed")
         expectMsgType[StatsResult](1.second).getMeanWordLength should be(3.875 +- 0.001)
       }
 

akka-samples/akka-sample-cluster-java/tutorial/index.html

@@ -352,17 +352,16 @@ in the contrib module. The <code>ClusterSingletonManager</code> is started on ea
 
 <p>
 We also need an actor on each node that keeps track of where current single master exists and
-delegates jobs to the <code>StatsService</code>. That is handled by the 
+delegates jobs to the <code>StatsService</code>. That is provided by the <code>ClusterSingletonProxy</code>. 
-<a href="#code/src/main/java/sample/cluster/stats/StatsFacade.java" class="shortcut">StatsFacade.java</a>
 </p>
 
 <p>
-The <code>StatsFacade</code> receives text from users and delegates to the current <code>StatsService</code>, the single
+The <code>ClusterSingletonProxy</code> receives text from users and delegates to the current <code>StatsService</code>, the single
 master. It listens to cluster events to lookup the <code>StatsService</code> on the oldest node.
 </p>
 
 <p>
-All nodes start <code>StatsFacade</code> and the <code>ClusterSingletonManager</code>. The router is now configured in
+All nodes start <code>ClusterSingletonProxy</code> and the <code>ClusterSingletonManager</code>. The router is now configured in
 <a href="#code/src/main/resources/stats2.conf" class="shortcut">stats2.conf</a>
 </p>
 

akka-samples/akka-sample-cluster-scala/src/main/scala/sample/cluster/stats/StatsFacade.scala

@@ -1,48 +0,0 @@
-package sample.cluster.stats
-
-import scala.collection.immutable
-import akka.actor.Actor
-import akka.actor.ActorLogging
-import akka.actor.ActorSelection
-import akka.actor.RootActorPath
-import akka.cluster.Cluster
-import akka.cluster.ClusterEvent.CurrentClusterState
-import akka.cluster.ClusterEvent.MemberEvent
-import akka.cluster.ClusterEvent.MemberRemoved
-import akka.cluster.ClusterEvent.MemberUp
-import akka.cluster.Member
-
-//#facade
-class StatsFacade extends Actor with ActorLogging {
-  import context.dispatcher
-  val cluster = Cluster(context.system)
-
-  // sort by age, oldest first
-  val ageOrdering = Ordering.fromLessThan[Member] { (a, b) => a.isOlderThan(b) }
-  var membersByAge: immutable.SortedSet[Member] = immutable.SortedSet.empty(ageOrdering)
-
-  // subscribe to cluster changes
-  // re-subscribe when restart
-  override def preStart(): Unit = cluster.subscribe(self, classOf[MemberEvent])
-  override def postStop(): Unit = cluster.unsubscribe(self)
-
-  def receive = {
-    case job: StatsJob if membersByAge.isEmpty =>
-      sender() ! JobFailed("Service unavailable, try again later")
-    case job: StatsJob =>
-      currentMaster.tell(job, sender())
-    case state: CurrentClusterState =>
-      membersByAge = immutable.SortedSet.empty(ageOrdering) ++ state.members.collect {
-        case m if m.hasRole("compute") => m
-      }
-    case MemberUp(m)         => if (m.hasRole("compute")) membersByAge += m
-    case MemberRemoved(m, _) => if (m.hasRole("compute")) membersByAge -= m
-    case _: MemberEvent      => // not interesting
-  }
-
-  def currentMaster: ActorSelection =
-    context.actorSelection(RootActorPath(membersByAge.head.address) /
-      "user" / "singleton" / "statsService")
-
-}
-//#facade

akka-samples/akka-sample-cluster-scala/src/main/scala/sample/cluster/stats/StatsSampleOneMaster.scala

@@ -5,6 +5,7 @@ import akka.actor.ActorSystem
 import akka.actor.PoisonPill
 import akka.actor.Props
 import akka.contrib.pattern.ClusterSingletonManager
+import akka.contrib.pattern.ClusterSingletonProxy
 
 object StatsSampleOneMaster {
   def main(args: Array[String]): Unit = {
@@ -32,7 +33,11 @@ object StatsSampleOneMaster {
         terminationMessage = PoisonPill, role = Some("compute")),
         name = "singleton")
       //#create-singleton-manager
-      system.actorOf(Props[StatsFacade], name = "statsFacade")
+
+      //#singleton-proxy
+      system.actorOf(ClusterSingletonProxy.props(singletonPath = "/user/singleton/statsService",
+        role = Some("compute")), name = "statsServiceProxy")
+      //#singleton-proxy
     }
   }
 }
@@ -41,7 +46,7 @@ object StatsSampleOneMasterClient {
   def main(args: Array[String]): Unit = {
     // note that client is not a compute node, role not defined
     val system = ActorSystem("ClusterSystem")
-    system.actorOf(Props(classOf[StatsSampleClient], "/user/statsFacade"), "client")
+    system.actorOf(Props(classOf[StatsSampleClient], "/user/statsServiceProxy"), "client")
   }
 }
 

akka-samples/akka-sample-cluster-scala/src/multi-jvm/scala/sample/cluster/stats/StatsSampleSingleMasterSpec.scala

@@ -10,6 +10,7 @@ import akka.actor.PoisonPill
 import akka.actor.Props
 import akka.actor.RootActorPath
 import akka.contrib.pattern.ClusterSingletonManager
+import akka.contrib.pattern.ClusterSingletonProxy
 import akka.cluster.Cluster
 import akka.cluster.Member
 import akka.cluster.MemberStatus
@@ -88,18 +89,19 @@ abstract class StatsSampleSingleMasterSpec extends MultiNodeSpec(StatsSampleSing
         singletonProps = Props[StatsService], singletonName = "statsService",
         terminationMessage = PoisonPill, role = Some("compute")), name = "singleton")
 
-      system.actorOf(Props[StatsFacade], "statsFacade")
+      system.actorOf(ClusterSingletonProxy.props(singletonPath = "/user/singleton/statsService",
+        role = Some("compute")), name = "statsServiceProxy")
 
       testConductor.enter("all-up")
     }
 
-    "show usage of the statsFacade" in within(40 seconds) {
+    "show usage of the statsServiceProxy" in within(40 seconds) {
-      val facade = system.actorSelection(RootActorPath(node(third).address) / "user" / "statsFacade")
+      val proxy = system.actorSelection(RootActorPath(node(third).address) / "user" / "statsServiceProxy")
 
       // eventually the service should be ok,
       // service and worker nodes might not be up yet
       awaitAssert {
-        facade ! StatsJob("this is the text that will be analyzed")
+        proxy ! StatsJob("this is the text that will be analyzed")
         expectMsgType[StatsResult](1.second).meanWordLength should be(
           3.875 +- 0.001)
       }

akka-samples/akka-sample-cluster-scala/tutorial/index.html

@@ -351,17 +351,16 @@ in the contrib module. The <code>ClusterSingletonManager</code> is started on ea
 
 <p>
 We also need an actor on each node that keeps track of where current single master exists and
-delegates jobs to the <code>StatsService</code>. That is handled by the 
+delegates jobs to the <code>StatsService</code>. That is provided by the <code>ClusterSingletonProxy</code>. 
-<a href="#code/src/main/scala/sample/cluster/stats/StatsFacade.scala" class="shortcut">StatsFacade.scala</a>
 </p>
 
 <p>
-The <code>StatsFacade</code> receives text from users and delegates to the current <code>StatsService</code>, the single
+The <code>ClusterSingletonProxy</code> receives text from users and delegates to the current <code>StatsService</code>, the single
 master. It listens to cluster events to lookup the <code>StatsService</code> on the oldest node.
 </p>
 
 <p>
-All nodes start <code>StatsFacade</code> and the <code>ClusterSingletonManager</code>. The router is now configured in
+All nodes start <code>ClusterSingletonProxy</code> and the <code>ClusterSingletonManager</code>. The router is now configured in
 <a href="#code/src/main/resources/stats2.conf" class="shortcut">stats2.conf</a>
 </p>