Book Image

Scala Reactive Programming

By : Rambabu Posa
Book Image

Scala Reactive Programming

By: Rambabu Posa

Overview of this book

Reactive programming is a scalable, fast way to build applications, and one that helps us write code that is concise, clear, and readable. It can be used for many purposes such as GUIs, robotics, music, and others, and is central to many concurrent systems. This book will be your guide to getting started with Reactive programming in Scala. You will begin with the fundamental concepts of Reactive programming and gradually move on to working with asynchronous data streams. You will then start building an application using Akka Actors and extend it using the Play framework. You will also learn about reactive stream specifications, event sourcing techniques, and different methods to integrate Akka Streams into the Play Framework. This book will also take you one step forward by showing you the advantages of the Lagom framework while working with reactive microservices. You will also learn to scale applications using multi-node clusters and test, secure, and deploy your microservices to the cloud. By the end of the book, you will have gained the knowledge to build robust and distributed systems with Scala and Akka.
Table of Contents (16 chapters)

Actor's Path versus Reference

In this section, we will compare the two important components of an Akka Actor:

  • ActorRef: ActorRef is a reference of an Actor object. When we create an Actor using ActorSystem, it returns ActorRef but not an Actor object:
      val actorRef:ActorRef =

As the outside world cannot interact with an Actor object directly, an outside Actor or a non-Actor can interact with another Actor indirectly using this ActorRef. When we create another Actor, ActorSystem returns a different ActorRef to that newly created Actor.

ActorRef is the same for a single Actor. It does not change during an Actor lifecycle. Two different Actor objects cannot have the same ActorRef.

  • ActorPath: ActorPath is the address of an Actor in the ActorSystem. In Akka, Actors are created in the hierarchy fashion...