Book Image

Microservices Development Cookbook

By : Paul Osman
Book Image

Microservices Development Cookbook

By: Paul Osman

Overview of this book

Microservices have become a popular choice for building distributed systems that power modern web and mobile apps. They enable you to deploy apps as a suite of independently deployable, modular, and scalable services. With over 70 practical, self-contained tutorials, the book examines common pain points during development and best practices for creating distributed microservices. Each recipe addresses a specific problem and offers a proven, best-practice solution with insights into how it works, so you can copy the code and configuration files and modify them for your own needs. You’ll start by understanding microservice architecture. Next, you'll learn to transition from a traditional monolithic app to a suite of small services that interact to ensure your client apps are running seamlessly. The book will then guide you through the patterns you can use to organize services, so you can optimize request handling and processing. In addition this, you’ll understand how to handle service-to-service interactions. As you progress, you’ll get up to speed with securing microservices and adding monitoring to debug problems. Finally, you’ll cover fault-tolerance and reliability patterns that help you use microservices to isolate failures in your apps. By the end of this book, you’ll have the skills you need to work with a team to break a large, monolithic codebase into independently deployable and scalable microservices.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Evolving APIs


APIs are contracts between clients and servers. Backward-incompatible changes to APIs can cause unexpected errors for clients of the service. In a microservices architecture, precautions have to be taken to ensure that changes to a service's API do not unintentionally cause cascading problems throughout the system.

A popular approach is to version your API, either through the URL or via content negotiation in request headers. Because they're generally easier to work with, and often easier to cache, URL prefixes or query strings tend to be more common—in this case, the API endpoint is either prefixed with a version string (that is, /v1/users) or called with a query string parameter specifying a version or even a date (that is, /v1/users?version=1.0 or /v1/users?version=20180122).

With edge proxies or service mesh configurations, it's even possible to run multiple versions of software in an environment and route requests based on the URL to older or newer versions of a service...