如何减慢Akka-Streams的制作人员的速度

Question

我试图解决akka-streams的问题。我希望我的初始生产者不断获取队列/ mongodb集合并在配置的时间间隔内完成。实现它的常见做法是什么？

Answer 1

You mean at a fixed time interval?

Start with Source.tick(...).map(loadFromMongo) ?

Put in a conflate that drops ticks to prevent querying the db more often than downstream can handle, if that is what you want.

Answer 2

Additionally, there is a concept called throttle. It can be used as follow:

Source(...).throttle(50, 1.second, 1, ThrottleMode.Shaping)

It allows you to specify a fetching interval eg above 50 items per second. An example can be found in the documentation here: http://doc.akka.io/docs/akka/current/scala/stream/stream-quickstart.html#Time-Based_Processing