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 server-sent events (SSE) 


Server-sent events (SSE) (https://www.w3.org/TR/eventsource/) is a standard that enables efficient server-to-client streaming using a two-part implementation. The first part is the EventSource API that is implemented at the client side to initiate the SSE connection with the server, and the second part is the push protocol that defines the event stream data format that is used for the server-to-client communication.

The EventSource API of SSE is defined as a part of the HTML5 standard by W3C (https://en.wikipedia.org/wiki/World_Wide_Web_Consortium) and is now supported by all the modern web browsers:

SSEs are primarily used to push real-time notifications, updates, and continuous data streams from server to client once an initial connection has been established by the client. Generally, the notifications and updates are pulled by the client by sending a request to the APIs or polling (https://en.wikipedia.org/wiki/Polling_(computer_science)) the server for updates...