CODEWITHSUNDEEP
scalaakka
user438454534
user438454534

Reputation: 3689

How to manage HTTP requests in Akka?

I'm using Spray in my application and from the examples I've see on Github it looks like people handle HTTP requests in Akka by passing the HTTPContext object around to all the actors and calling onComplete { } on the Future in the last actor.

Is sending the context deep down in the application really a good idea ? This way every event object will have a context parameter.

How do we handle HTTP requests & response properly in Akka? I've read this article but I would like to know people's thoughts who run Akka in production on the right way of achieving this.

Upvotes: 4

Views: 484

Answers (1)

mattinbits
mattinbits

Reputation: 10428

I prefer to use the ask pattern in the Spray service, and the onSuccess directive, e.g.:

trait MyService extends HttpService {

  def worker: ActorRef

  implicit def timeout:Timeout

  implicit def ec:ExecutionContext

  def askWorker: Future[String] = (worker ? "Hello").mapTo[String]

  def myRoute = path("/") {
    get {
      onSuccess(askWorker){
        case str => complete(str)
      }
    }
  }
}

Then a concrete actor such as:

class ServiceActor extends MyService with Actor {

  implicit val ec = context.system

  implicit val timeout = Timeout(3 seconds)

  val worker = context.actorOf(Props[WorkerActor])

  override def actorRefFactory = context.system

  def receive = runRoute(myRoute)
}

I like this pattern rather than passing the request context around since it means that the other actors don't have to have any concept of Http. The service could be completely replaced with a different protocol. In this example the worker actor is can be something like:

class WorkerActor extends Actor {

  def receive = {
    case "Hello" => sender() ! "Hello World"
  }
}

Upvotes: 4

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