Building Microservices, 2nd Edition

Chapter 1. What Are Microservices?

Microservices have become an increasingly popular architecture choice in the half decade or more since I wrote the first edition of this book. I can’t claim credit for the subsequent explosion in popularity, but the rush to make use of microservice architectures means that while many of the ideas I captured previously are now tried and tested, new ideas have come into the mix at the same time that earlier practices have fallen out of favor. So it’s once again time to distill the essence of microservice architecture while highlighting the core concepts that make microservices work.

This book as a whole is designed to give a broad overview of the impact that microservices have on various aspects of software delivery. To start us off, this chapter will take a look at the core ideas behind microservices, the prior art that brought us here, and some reasons why these architectures are used so widely.

Microservices at a Glance

Microservices are independently releasable services that are modeled around a business domain. A service encapsulates functionality and makes it accessible to other services via networks—you construct a more complex system from these building blocks. One microservice might represent inventory, another order management, and yet another shipping, but together they might constitute an entire ecommerce system. Microservices are an architecture choice that is focused on giving you many options for solving the problems you might face. ...