scala - Akka Actor - 创建 Actor 池

Question

我在 Scala 中创建了以下 Akka Actor 代码。当创建单个 workerActor 时，代码工作正常。但是，当我尝试使用循环逻辑创建一个工作角色池时，代码默默地失败了。知道如何解决这个问题吗？如何获得更多要打印的调试信息？

import scala.collection.immutable.Map
import scala.collection.mutable.ArrayBuffer

import akka.actor.actorRef2Scala
import akka.actor.ActorSystem
import akka.actor.Props
import scala.concurrent.Await
import scala.concurrent.duration._
import akka.pattern.ask
import akka.util.Timeout
import akka.actor._
import org.junit._
import org.junit.Assert._
import messaging.actors._
import akka.routing.RoundRobinRouter
import akka.routing._

class MainEngineActorTest {

  @Test
  def testMainActor () = {
  val _system = ActorSystem("MainEngineActor")
  val master = _system.actorOf(Props[MainEngineActor], name = "EngineActor")

  println ("Created Main Engine Actor")


  implicit val timeout = Timeout(5 seconds)

  val userID = new UserID ("test1")

  println ("Sending messages")

  for (i <- ( 1 to 10)) {
      master ! "Hello"
      master ! "World"
  }

  }
}

class MainEngineActor extends Actor with ActorLogging{

  // works if we create only a single workerActor
  //val workerActors = context.actorOf(Props[WorkerActor], name = "WorkerActors")

  // Doesn't work when we create a pool of worker actors - how do we fix this? 
  // why doesn't this work and why aren't any error messages printed?
  val workerActors = context.actorOf(RoundRobinPool(5).props(Props[WorkerActor]), name = "WorkerActors")

   def receive: Receive = {     
     case request => {       
       workerActors forward request
     }    
  }
}  

class WorkerActor extends Actor {

   def receive: Receive = {               
     case request => {
       println ("RequestReceived =" + request)
     }
   }
}

Answer 1

尝试像这样创建您的池:

val workerActors = context.actorOf(Props[WorkerActor].withRouter(RoundRobinPool(5)), name = "WorkerActors")

此外，将其作为 Junit 测试运行时，程序会在子 actors 有机会接收到消息之前终止。我通过在将 Hello 和 World 消息发送到 master< 的循环之后添加一个 Thread.sleep(5000) 来验证这一点。然后，我稍微调整了您的代码以使用 akka-testkit 中的 Akka 的 TestActorRef，这将强制所有内容都使用 CallingThreadDispatcher 以在整个测试过程中同步执行，并且一切都按预期进行。我更改的两行是:

implicit val _system = ActorSystem("MainEngineActor")
val master = TestActorRef(new MainEngineActor())