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

Modeling concurrency with dependent futures


We saw in a previous recipe that we can use asynchronous methods to make service calls that are handled in separate threads. This is essential because blocking on network I/O would severely limit the number of incoming requests our service would be able to handle. A service that blocks on the network I/O would only be able to handle a relatively small number of requests per process, requiring us to spend more resources on horizontal scaling. In the example we used, the message service needed to call the social graph service for two users, the sender, and the recipient of a message, and make sure that the two users followed each other before allowing a message to be sent. We modified our request methods to return the CompletableFuture instances that wrapped the response, and then waited on all of the results to finish before verifying that the sender and recipient of the message had a symmetric following relationship. This model works fine when...