When to use the Ask template in Acca

Question

I started to learn Akka, and in many official examples I see that it is request-responseimplemented using the template tell. That is, after the employee has done his work, he sends the result as a new message back to the sender. For example, in this, the official Pi approximation guide showed how to develop an application in which a wizard sends some work to employees and then expects results as another message.

Master Code:

def receive = {
  case Calculate ⇒
    for (i ← 0 until nrOfMessages) workerRouter ! Work(i * nrOfElements, nrOfElements)
  case Result(value) ⇒
    pi += value
    nrOfResults += 1
    if (nrOfResults == nrOfMessages) {
      // Send the result to the listener
      listener ! PiApproximation(pi, duration = (System.currentTimeMillis - start).millis)
      // Stops this actor and all its supervised children
      context.stop(self)
    }
}

Work code:

 def receive = {
    case Work(start, nrOfElements) ⇒
      sender ! Result(calculatePiFor(start, nrOfElements)) // perform the work
  }

But I wonder why this example did not use a query template? What is wrong with using the query template here?

, : - ?

• PoisonPill ?
• - Broadcast(PoisonPill)?
• ?

Answer 1

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, tell tell sender , .

, , , receive, receive, - ask.

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