Book Image

Microservices with Clojure

By : Anuj Kumar
Book Image

Microservices with Clojure

By: Anuj Kumar

Overview of this book

The microservice architecture is sweeping the world as the de facto pattern with which to design and build scalable, easy-tomaintain web applications. This book will teach you common patterns and practices, and will show you how to apply these using the Clojure programming language. This book will teach you the fundamental concepts of architectural design and RESTful communication, and show you patterns that provide manageable code that is supportable in development and at scale in production. We will provide you with examples of how to put these concepts and patterns into practice with Clojure. This book will explain and illustrate, with practical examples, how teams of all sizes can start solving problems with microservices. You will learn the importance of writing code that is asynchronous and non-blocking and how Pedestal helps us do this. Later, the book explains how to build Reactive microservices in Clojure that adhere to the principles underlying the Reactive Manifesto. We finish off by showing you various ways to monitor, test, and secure your microservices. By the end, you will be fully capable of setting up, modifying, and deploying a microservice with Clojure and Pedestal.
Table of Contents (18 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Using WebSockets


WebSockets is a communications protocol (https://en.wikipedia.org/wiki/Communication_protocol) that provides full-duplex (https://en.wikipedia.org/wiki/Duplex_(telecommunications)#FULL-DUPLEX) communication channels over a single TCP connection between client and server. It allows clients to send messages to the server and receive server events over the same TCP connection without polling. Compared to Server-Sent Events (SSE) (https://www.w3.org/TR/eventsource/), WebSockets support full-duplex communication between client and server instead of a one-way push. Also, SSEs are implemented over HTTP, which is an entirely different TCP protocol compared to WebSocket. Although both protocols are different, they both depend on the TCP layer. 

Note

RFC 6455 (https://tools.ietf.org/html/rfc6455) states that WebSocket is designed to work over HTTP ports 80 and 443 as well as to support HTTP proxies and intermediaries, thus making it compatible with the HTTP protocol. To achieve compatibility...