如何从一个主要的方法终止Akka演员系统？

Question

我已经使用了Akka和ReactiveMongo的ReactiveMongo应用程序。没有用户定义的参与者。应用程序是从main方法启动的。

问题是JVM在main方法完成后会永远运行。这就是我现在要做的：

val g = (file: String) => RunnableGraph.fromGraph(GraphDSL.create(Sink.ignore) {
  implicit builder =>
    sink =>
      import GraphDSL.Implicits._

      // Source
      val A: Outlet[(String, String)] = builder.add(Source.fromIterator(() => parseMovies(file).iterator)).out
      // Flow
      val B: FlowShape[(String, String), Either[String, Movie]] = builder.add(findMovie)
      // Flow
      val C: FlowShape[Either[String, Movie], Option[String]] = builder.add(persistMovie)

      A ~> B ~> C ~> sink.in

      ClosedShape
})

def main(args: Array[String]): Unit = {
  require(args.size >= 1, "Path to file is required.")

  g(args(0)).run
    .onComplete(_ => Await.result(system.terminate(), 5.seconds))
}

我读过这线程和这，它们都不起作用。system.shutdown是不受欢迎的，我没有任何明确的演员可看。我可以给system.exit打电话，但这不太优雅。

从日志上看，阿克卡似乎试图关闭，但我看到了一堆蒙戈消息。

2017-01-13 11:35:57.320 [DEBUG] a.e.EventStream.$anonfun$applyOrElse$4 - shutting down: StandardOutLogger started
2017-01-13 11:36:05.397 [DEBUG] r.c.a.MongoDBSystem.debug - [Supervisor-1/Connection-2] ConnectAll Job running... Status: {{NodeSet None Node[localhost:27017: Primary (10/10 available connections), latency=6], auth=Set() }}
2017-01-13 11:36:05.420 [DEBUG] r.c.a.MongoDBSystem.debug - [Supervisor-1/Connection-2] RefreshAll Job running... Status: {{NodeSet None Node[localhost:27017: Primary (10/10 available connections), latency=6], auth=Set() }}
// more of MongoDBSystem.debug messages

为什么it.just.die不

Answer 1

我认为您想要添加一个关机钩子或调用actorSystem.registerOnTermination(driver.close())

def main(args: Array[String]): Unit = {
  import akka.actor.CoordinatedShutdown
  require(args.size >= 1, "Path to file is required.")

  CoordinatedShutdown(system).addTask(CooordinatedShutdown.PhaseBeforeActorSystemTerminate, "shutdownMongoDriver") { () => driver.close(5.seconds); Future.successful(Done) }

  g(args(0)).run.onComplete(_ => CoordinatedShutdown(system).run())    
}