Akka actors always times out waiting for future - scala

Question

I have the following actor as defined below meant to "login" a user.
object AuthenticationActor {
def props = Props[AuthenticationActor]
case class LoginUser(id: UUID)
}
class AuthenticationActor #Inject()(cache: CacheApi, userService: UserService) extends Actor{
import AuthenticationActor._
def receive = {
case LoginEmployee(id: UUID) => {
userService.getUserById(id).foreach {
case Some(e) => {
println("Logged user in")
val sessionId = UUID.randomUUID()
cache.set(sessionId.toString, e)
sender() ! Some(e, sessionId)
}
case None => println("No user was found")
}
}
}
}
Note: userService.getUserById returns a Future[Option[User]]
And the following very simplistic API cal to it
class EmployeeController #Inject()(#Named("authentication-actor") authActor: ActorRef)(implicit ec: ExecutionContext) extends Controller {
override implicit val timeout: Timeout = 5.seconds
def login(id: UUID) = Action.async { implicit request =>
(authActor ? LoginUser(id)).mapTo[Option[(User, UUID)]].map {
case Some(authInfo) => Ok("Authenticated").withSession(request.session + ("auth" -> authInfo._2.toString))
case None => Forbidden("Not Authenticated")
}
}
}
Both println calls will execute, but login call will always fail saying that the ask has time out. Any suggestions?

Answer 1

When you do such thing (accessing sender within Futures callback) you need to store sender in a val in outter scope when you receive request because it is very likely change before Future completes.
def receive = {
case LoginEmployee(id: UUID) => {
val recipient = sender
userService.getUserById(id).foreach {
case Some(e) => {
...
recipient ! Some(e, sessionId)
}
...
}
}
}
You also never send a result when user wasn't found.
What you actually should do here is pipe the Future result to the sender
def receive = {
case LoginEmployee(id: UUID) => {
userService.getUserById(id) map { _.map { e =>
val sessionId = UUID.randomUUID()
cache.set(sessionId.toString, e)
(e, sessionId)
}
} pipeTo sender
}
}
or with prints
def receive = {
case LoginEmployee(id: UUID) => {
userService.getUserById(id) map {
case Some(e) =>
println("logged user in")
val sessionId = UUID.randomUUID()
cache.set(sessionId.toString, e)
Some(e, sessionId)
case None =>
println("user not found")
None
} pipeTo sender
}
}