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)

Understanding the Reactive Design Pattern

A Tell Design Pattern means a Reactive component sends a request to another Reactive component and does not wait or look for that other component's Response. It just fires that Request message and forgets about it. This is why it is also known as Fire-and-Forget Design Pattern.

Akka Toolkit has implemented the same design pattern to send messages between its components (Actors). It has implemented this pattern as the function tell.

We can use this tell function to send a Message from one Actor to another, as shown here:


We can also write the preceding code snippet in another format, as follows, by using one of the useful features of the Scala Programming Language:

actorRef tell MyMessage

Akka Toolkit also has a Tell Operator to perform the same job:

actorRef ! MyMessage

Here, the ! symbol is a Tell Operator...