Demonstration of Akka Cluster Singleton Communication Problem

MyClusterActor.scala

package sample.cluster.simple

import com.typesafe.config.ConfigFactory
import akka.actor.ActorSystem
import akka.actor.Props
import akka.actor._
import akka.contrib.pattern.ClusterSingletonManager
import akka.contrib.pattern.ClusterSingletonProxy

class MyClusterActor extends Actor {
  def receive = {
    case msg => {
      println("MyClusterActor got *" + msg + "* from " + sender().path)
      sender() ! "Here's a response from MyClusterActor"
    }
  }
}
case class Start(actor: ActorRef)
class MyRemoteActor extends Actor {
  def receive = {
    case Start(actor) => {
      println("MyRemoteActor got Start with " + actor.path)
      actor ! "Hello from RemoteActor"
    }
    case msg => {
      println("MyRemoteActor got *" + msg + "* from " + sender().path)
    }
  }
}
object RemoteSystem {
  val remoteConfig = ConfigFactory.parseString("akka.actor.provider=\"akka.remote.RemoteActorRefProvider\"").
    withFallback(ConfigFactory.parseString("akka.remote.enabled-transports=[\"akka.remote.netty.tcp\"]")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.hostname=\"127.0.0.1\"")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.port=2551"))
  val remoteSystem = ActorSystem("RemoteSystem", remoteConfig)
  val remoteActor = remoteSystem.actorOf(Props[MyRemoteActor], "myremoteactor")
  val clusterConfig = ConfigFactory.parseString("akka.actor.provider=\"akka.cluster.ClusterActorRefProvider\"").
    withFallback(ConfigFactory.parseString("akka.remote.enabled-transports=[\"akka.remote.netty.tcp\"]")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.hostname=\"127.0.0.1\"")).
    withFallback(ConfigFactory.parseString("akka.cluster.seed-nodes=[\"akka.tcp://[email protected]:2553\"]")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.port=2552"))
  val clusterSystem = ActorSystem("ClusterSystem", clusterConfig)
  val clusterActor = clusterSystem.actorOf(ClusterSingletonProxy.props(
    singletonPath = "/user/myclusteractor/active",
    role = None),
    name = "MyClusterActor")
}
object ClusterSystem {
  val clusterConfig = ConfigFactory.parseString("akka.actor.provider=\"akka.cluster.ClusterActorRefProvider\"").
    withFallback(ConfigFactory.parseString("akka.remote.enabled-transports=[\"akka.remote.netty.tcp\"]")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.hostname=\"127.0.0.1\"")).
    withFallback(ConfigFactory.parseString("akka.cluster.seed-nodes=[\"akka.tcp://[email protected]:2553\"]")).
    withFallback(ConfigFactory.parseString("akka.remote.netty.tcp.port=2553"))
  val clusterSystem = ActorSystem("ClusterSystem", clusterConfig)
  clusterSystem.actorOf(ClusterSingletonManager.props(Props(classOf[MyClusterActor]), "active",
    PoisonPill, None), "myclusteractor")
  def setup() = println("Setting up ClusterSystem")
}

tip: scala supports:

parseString("""akka.remote.enabled-transports="akka.remote.netty.tcp"
                     akka.remote.netty.tcp.hostname="127.0.0.1"
                 """)