60 lines
1.8 KiB
Scala
60 lines
1.8 KiB
Scala
package scala.docs.cluster
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import language.postfixOps
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import scala.concurrent.duration._
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import akka.actor.Actor
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import akka.actor.ActorRef
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import akka.actor.ActorSystem
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import akka.actor.Props
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import akka.actor.Terminated
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import akka.pattern.ask
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import akka.util.Timeout
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import com.typesafe.config.ConfigFactory
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import java.util.concurrent.atomic.AtomicInteger
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//#frontend
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class TransformationFrontend extends Actor {
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var backends = IndexedSeq.empty[ActorRef]
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var jobCounter = 0
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def receive = {
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case job: TransformationJob if backends.isEmpty =>
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sender() ! JobFailed("Service unavailable, try again later", job)
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case job: TransformationJob =>
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jobCounter += 1
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backends(jobCounter % backends.size) forward job
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case BackendRegistration if !backends.contains(sender()) =>
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context watch sender()
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backends = backends :+ sender()
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case Terminated(a) =>
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backends = backends.filterNot(_ == a)
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}
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}
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//#frontend
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object TransformationFrontend {
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def main(args: Array[String]): Unit = {
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// Override the configuration of the port when specified as program argument
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val port = if (args.isEmpty) "0" else args(0)
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val config = ConfigFactory.parseString(s"akka.remote.netty.tcp.port=$port").
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withFallback(ConfigFactory.parseString("akka.cluster.roles = [frontend]")).
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withFallback(ConfigFactory.load())
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val system = ActorSystem("ClusterSystem", config)
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val frontend = system.actorOf(Props[TransformationFrontend], name = "frontend")
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val counter = new AtomicInteger
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import system.dispatcher
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system.scheduler.schedule(2.seconds, 2.seconds) {
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implicit val timeout = Timeout(5 seconds)
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(frontend ? TransformationJob("hello-" + counter.incrementAndGet())) onSuccess {
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case result => println(result)
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}
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}
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}
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}
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