Integrating streams with Akka actors
The stages of a stream are ultimately lines of code that are fused and run on actors. This is why it is natural that Akka Stream has full integration with Akka actors. At the time of writing, there are multiple ways of interacting with Actors. One possibility is to use the traits named ActorPublisher and ActorSubscriber. These traits create an actor source or sink; however, they do not honor the back-pressure mechanism, and there are plans to decommission them in Akka 2.5+. Therefore, it is not recommended that you use them.
Instead of using ActorPublisher and ActorSubscriber, we will see Source.queue for our Source actor, Sink.actorRefWithAck for our Sink actor, and mapAsync plus ask for our Flow.
Getting ready
In this recipe, we will see how to create a Source that can emit elements into a stream, how to create a flow that can ask an actor, and how to create a Sink that pulls elements from a stream.
How to do it...
For this recipe, perform the following...
