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

Datomic architecture


Datomic is a distributed database that supports ACID (http://docs.datomic.com/acid.html) transactions and stores data as immutable facts. Datomic is focused on providing a robust transaction manager to keep the underlying data consistent, a data model to store immutable facts, and a query engine to help retrieve data as facts over time. Instead of having its own storage, it relies on an external storage service (http://docs.datomic.com/storage.html) to store the data on disk.

Datomic versus traditional database

A typical database is implemented as a monolithic application that contains the storage engine, query engine, and the transaction manager all packaged as a single application to which clients connect to store and retrieve data. Datomic, on the other hand, takes a radical approach of separating out the Transaction Manager (Transactor) as a separate process to handle all the transactions and commit the data to an underlying Storage Service that acts as a persistence...