Book Image

Scala Microservices

By : Selvam Palanimalai, Jatin Puri
Book Image

Scala Microservices

By: Selvam Palanimalai, Jatin Puri

Overview of this book

<p>In this book we will learn what it takes to build great applications using Microservices, the pitfalls associated with such a design and the techniques to avoid them. </p><p>We learn to build highly performant applications using Play Framework. You will understand the importance of writing code that is asynchronous and nonblocking and how Play leverages this paradigm for higher throughput. The book introduces Reactive Manifesto and uses Lagom Framework to implement the suggested paradigms. Lagom teaches us to: build applications that are scalable and resilient to failures, and solves problems faced with microservices like service gateway, service discovery, communication and so on. Message Passing is used as a means to achieve resilience and CQRS with Event Sourcing helps us in modelling data for highly interactive applications. </p><p>The book also shares effective development processes for large teams by using good version control workflow, continuous integration and deployment strategies. We introduce Docker containers and Kubernetes orchestrator. Finally, we look at end to end deployment of a set of scala microservices in kubernetes with load balancing, service discovery and rolling deployments. </p><p></p>
Table of Contents (12 chapters)

Effective Communication

In this chapter, we will look at the significance of the asynchronous mode of communication using message passing across microservices. We will also understand that the secret to being resilient to failures is communication via message passing.

We will explore Apache Kafka and see its usage for different purposes, including as a message broker and for a publish-subscribe model.

Lagom provides a message broker API (on top of Apache Kafka) for ease of access from our microservices. The message broker API is a continuation of the Persistence API, and we will see how together they let us do solid engineering with a few lines of code.

We will cover the following topics in this chapter:

  • Asynchronous mode of communication and its significance
  • Apache Kafka and its usage-message broker
  • Lagom message broker API