Akka/Scala example source code file (ClusterSingletonProxySpec.scala)

This example Akka source code file (ClusterSingletonProxySpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actorlogging, actorsys, akka, cluster, clustersingletonproxyspec, clustersingletonproxysystem, concurrent, got, none, poisonpill, singleton, string, test, testing, testkit, time

The ClusterSingletonProxySpec.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.contrib.pattern

import org.scalatest.{ BeforeAndAfterAll, Matchers, WordSpecLike }
import akka.testkit.{ TestProbe, TestKit }
import akka.actor._
import com.typesafe.config.ConfigFactory
import akka.cluster.Cluster
import scala.concurrent.duration._

class ClusterSingletonProxySpec extends WordSpecLike with Matchers with BeforeAndAfterAll {

  import ClusterSingletonProxySpec._

  val seed = new ActorSys()
  seed.cluster.join(seed.cluster.selfAddress)

  val testSystems = (0 until 4).map(_ ⇒ new ActorSys(joinTo = Some(seed.cluster.selfAddress))) :+ seed

  "The cluster singleton proxy" must {
    "correctly identify the singleton" in {
      testSystems.foreach(_.testProxy("Hello"))
      testSystems.foreach(_.testProxy("World"))
    }
  }

  override def afterAll() = testSystems.foreach(_.system.shutdown())
}

object ClusterSingletonProxySpec {

  class ActorSys(name: String = "ClusterSingletonProxySystem", joinTo: Option[Address] = None)
    extends TestKit(ActorSystem(name, ConfigFactory.parseString(cfg))) {

    val cluster = Cluster(system)
    joinTo.foreach(address ⇒ cluster.join(address))

    cluster.registerOnMemberUp {
      system.actorOf(ClusterSingletonManager.props(
        singletonProps = Props[Singleton],
        singletonName = "singleton",
        terminationMessage = PoisonPill,
        role = None,
        maxHandOverRetries = 5,
        maxTakeOverRetries = 2), name = "singletonManager")
    }

    val proxy = system.actorOf(ClusterSingletonProxy.props("user/singletonManager/singleton", None), s"singletonProxy-${cluster.selfAddress.port.getOrElse(0)}")

    def testProxy(msg: String) {
      val probe = TestProbe()
      probe.send(proxy, msg)
      // 25 seconds to make sure the singleton was started up
      probe.expectMsg(25.seconds, "Got " + msg)
    }
  }

  val cfg = """akka {

                loglevel = INFO

                cluster {
                  auto-down-unreachable-after = 10s

                  min-nr-of-members = 2
                }

                actor.provider = "akka.cluster.ClusterActorRefProvider"

                remote {
                  log-remote-lifecycle-events = off
                  netty.tcp {
                    hostname = "127.0.0.1"
                    port = 0
                  }
                }
              }
            """

  class Singleton extends Actor with ActorLogging {

    log.info("Singleton created on {}", Cluster(context.system).selfAddress)

    def receive: Actor.Receive = {
      case msg ⇒
        sender() ! "Got " + msg
    }
  }

}