Start Building RESTful Microservices using Lagom: A Practical Approach to Modern, Domain-Driven, Event-Driven, Scalable and Reactive Microservices using Lagom with Scala (Knoldus Reactive Programming Series)

Book Description

This book is a part of Knoldus Reactive Programming Series. Today most of the big successful applications are moving to microservices architecture. There have been lot of buzz around the word ‘Microservices’ in the past few years. But just because something is buzzy doesn’t mean we should start following it. It is really important to think about how you can get the hype to work in your application. Few years ago, applications were much simpler and required all solutions at one place, we call them monolithic applications. Now a days markets are changing rapidly. You either adapt quickly or you go out of business. If your application is successful, it will eventually grow and become huge with the frequent addition of new codes, thus overloading the IDE and reducing the developer’s productivity. Any minor malfunctioning in a single component can affect the entire application. These type of applications also have a barrier in adopting the new technologies because it will affect the entire application. In this book, you will learn how easily and effectively you can transform monolithic applications into microservices.

The microservices architectural style is an approach to developing a single application as a suite of small services. These services are built around business capabilities and are independently deployable by fully automated deployment machinery.The advantages of Microservices over the monstrous monolithic system have convinced some of the major enterprises like Netflix, Amazon, and eBay. Microservices can be developed using different programming languages. There are many frameworks available to build microservices but they are good at helping you building the first one and you are left alone with all the others. Lagom extends that to systems of microservices, and thus, building a larger system. There are many other reasons to use Lagom, which you will learn in this book.We have written this book for those who want to start developing REST API right away and have a basic understanding of Scala. We don't exhaustively list all the features of Lagom. We don't make you suffer through long and contrived example. We have tried to explain every topic of this book with short and easy to understand examples along with the test-cases.Lagom is available for both Java and Scala but in this book, we will go with Scala. We choose Scala because it reduces the boilerplate code and we can concentrate on the logic of our problems. In Scala, you are not limited to just object-oriented patterns to implement your code, you can bring in functional paradigms as well.By the end of this book, you will be fully capable of setting up, modifying, and deploying a microservice with Lagom. You will know how to quickly build lighter and faster services that can be deployed easily in a production environment. You will be able to migrate a monolithic application to microservices based application.What You'll Learn

• Advantage of using Microservices architecture over monolithic
• Introduction to Lagom
• Start building services in Lagom
• CQRS and Event Sourcing with Lagom
• Circuit Breakers
• Exception Handling in Lagom
• Testing in Lagom
• Lagom in Production

By the end of the book, you will get the links of multiple sample projects of Lagom. For ex:Lagom with ScalaLagom with JavaLagom with KafkaLagom StreamingYou can clone these sample projects according to your requirement and start building restful web services.Who This Book Is ForThose who want to start working on microservices architecture right away. The only prerequisite to this book is that you are "comfortable" with Scala. However language is not a barrier, even if you want to develop java microservices using Lagom, you can still refer this book to understand the concept. We have used the latest version of Lagom in this book.