java - spray scala构建非阻塞servlet

Question

我使用 spray 和 akka actor 构建了一个 scala 应用程序。

我的问题是请求是同步的，服务器不能同时管理很多请求。

这是正常行为吗？我该怎么做才能避免这种情况？

这是我的启动代码:

object Boot extends App with Configuration {

  // create an actor system for application
  implicit val system = ActorSystem("my-service")
//context.actorOf(RoundRobinPool(5).props(Props[TestActor]), "router")
  // create and start property service actor
  val RESTService = system.actorOf(Props[RESTServiceActor], "my-endpoint")

  // start HTTP server with property service actor as a handler
  IO(Http) ! Http.Bind(RESTService, serviceHost, servicePort)
}

Actor 代码:

class RESTServiceActor extends Actor 
                            with RESTService  {
  implicit def actorRefFactory = context

  def receive = runRoute(rest)
}



trait RESTService extends HttpService  with SLF4JLogging{
  val myDAO = new MyDAO



  val AccessControlAllowAll = HttpHeaders.RawHeader(
    "Access-Control-Allow-Origin", "*"
  )
  val AccessControlAllowHeadersAll = HttpHeaders.RawHeader(
    "Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"
  )
  val rest =  respondWithHeaders(AccessControlAllowAll, AccessControlAllowHeadersAll) { 
    respondWithMediaType(MediaTypes.`application/json`){
      options {
            complete {
              ""
            }
          } ~
      path("some"/"path"){
         get {
            parameter('parameter){ (parameter) => 
              ctx: RequestContext =>
                    handleRequest(ctx) {
                      myDAO.getResult(parmeter)
                    }
            }
          }
        } 
    }
  }

    /**
   * Handles an incoming request and create valid response for it.
   *
   * @param ctx         request context
   * @param successCode HTTP Status code for success
   * @param action      action to perform
   */
  protected def handleRequest(ctx: RequestContext, successCode: StatusCode = StatusCodes.OK)(action: => Either[Failure, _]) {
    action match {
      case Right(result: Object) =>
        println(result)
        ctx.complete(successCode,result.toString())
      case Left(error: Failure) =>
      case _ =>
        ctx.complete(StatusCodes.InternalServerError)
    }
  }
}

我看到了:

Akka Mist provides an excellent basis for building RESTful web services in Scala since it combines good scalability (enabled by its asynchronous, non-blocking nature) with general lightweight-ness

这就是我所缺少的吗？ spray 是默认使用它还是我需要添加它，如何添加？

我对此有点困惑。任何帮助表示赞赏。

Answer 1

如果您是从头开始，我建议使用 Akka HTTP，记录在 http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0-M4/scala/http/ .它是 Spray 的一个端口，但使用 Akka Streams，这将是重要的进步。

就使您的代码完全异步而言，关键模式是将 Future 返回到您的结果，而不是结果数据本身。换句话说，RESTServiceActor 应该返回一个返回数据的 Future，而不是实际数据。这将允许 Spray/Akka HTTP 接受额外的连接，服务参与者的异步完成将在完成时返回结果。