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

Pedestal concepts


Pedestal is an API-first Clojure framework that provides a set of libraries to build reliable and highly concurrent services that are dynamic in nature. It is an extensible framework that is data-driven and implemented using protocols (https://clojure.org/reference/protocols) to reduce the coupling between its components. It favors data over functions and functions over macros. It allows for the creation of data-driven routes and handlers that can apply a different behavior at runtime based on incoming requests. This makes it possible to create highly flexible and dynamic services that are well suited for microservice-based applications. It also supports the building of scalable asynchronous services using server-sent events (SSE) and WebSockets:

The Pedestal architecture is based on two main concepts, Interceptors and Context Map, and two secondary concepts, Chain Providers and Network Connectors. All the core logic of the Pedestal framework has been implemented as Interceptors...