动态改变 Akka Streams 的节流级别

Question

有什么方法可以动态地改变源的节流参数，以实现一个上升机制，例如每过一秒节流就会减少/增加？

Answer 1

Akka throttle function offers calculating throttle based on cost. We can use it to dynamically change throttling rate.

Example:

private val weight = new AtomicInteger(1)

Source(1 to 1000)
  .throttle(1000, 1.second, _ => 1000 / weight.get())
  .runWith(Sink.foreach(println))

while (true) {
  val newWeight = StdIn.readLine().toInt
  weight.set(newWeight)
}

Initial throttling rate is 1/s. Then we can change it by changing weight. I used factor of 1000 due to costFunction returning integer. It can be increased for better granularity.

If you want to change throttling based on passing time you just need to change weight as the time passes.