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)

Data modelling

We all love Create Read Update Delete (CRUD) system (https://en.wikipedia.org/wiki/Create,_read,_update_and_delete) when dealing with persistent storage. It is simple, easy to understand and maintain. It has stood the test of time and it works.

There is nothing wrong with CRUD and it should be used if the solves the problem in an elegant manner. But there are scenarios when data modelling with CRUD does create problems and we need to equip ourselves to use the appropriate design to fix our need.

Bounded context

As a small project grows bigger, the domain that was initially modeled starts meaning different things in different scenarios. Each domain model is only sensible in certain limits within a system. For...