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

Workflows for Helping Hands


Data workflows are the backbone of any microservices-based architecture. They define the sequence of messages and events that are generated among the services to accomplish a desired task. A workflow may consist of both synchronous and asynchronous messages.

Note

Workflows shown in this section are only for explanatory purposes and do not conform to the exact semantics of sequence diagrams (https://en.wikipedia.org/wiki/Sequence_diagram). Details of authentication, authorization, validation, and error conditions have been omitted intentionally.

Service provider workflow

The service provider workflow consists of Service Provider, Lookup Service, and Alerting Service. The Service Provider Component exposes endpoints for users to create and update service providers for the Helping Hands application, as shown in the following diagram:

For the create operation, the Service Provider service first validates the input request for the required parameters and privileges, then...