Julien Ponge - Vert.x in Action: Asynchronous and Reactive Java

Asynchronous and Reactive Java

Julien Ponge

Foreword by Martijn Verberg

To comment go to liveBook

Manning

Shelter Island

For more information on this and other Manning titles go to

manning.com

For online information and ordering of these and other Manning books, please visit manning.com. The publisher offers discounts on these books when ordered in quantity.

For more information, please contact

Special Sales Department

Manning Publications Co.

20 Baldwin Road

PO Box 761

Shelter Island, NY 11964

Email: orders@manning.com

2020 by Manning Publications Co. All rights reserved.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by means electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in the book, and Manning Publications was aware of a trademark claim, the designations have been printed in initial caps or all caps.

Recognizing the importance of preserving what has been written, it is Mannings policy to have the books we publish printed on acid-free paper, and we exert our best efforts to that end. Recognizing also our responsibility to conserve the resources of our planet, Manning books are printed on paper that is at least 15 percent recycled and processed without the use of elemental chlorine.

ISBN: 9781617295621

To Marie and Mathieu

I first ran across Vert.x in 2014 when I was the CTO at jClarity, a start-up Id co-founded with Ben Evans and Kirk Pepperdine. We were building a SaaS that needed to receive large amounts of telemetry data, run analytics over it, and then present tuning recommendations to the end-user. Our use case required non-blocking, asynchronous communication, multi-tenancy (cost savings!), the ability to talk to data stores, and decent support for secured WebSockets. It would need to be a distributed system that scaled. Enter Vert.x!

John Oliver, our Chief Scientist, discovered this flexible framework for building asynchronous applications. Vert.x could do it all. It had blazing performance, thanks to its Netty base, and it supported all other functional and non-functional requirements. Even better was that it was backed by a bunch of brilliant, humble, and friendly engineers, such as Julien Ponge, the author of this book.

Vert.x is deliberately a non-prescriptive framework, in that it doesnt guide you down a narrow path like, say, Spring Boot does. It's more like a toolkit of high-quality tools that are designed to work together, but you have to decide how to integrate them. That's where this book becomes your indispensable guide.

Part one of the book exposes the two main building blocks, the Verticle processing unit and the event bus, along with how the asynchronous programming model works with them. But part two is where the real value lies. Julien guides you through the best practices around designing a reactive application and plugging in Vert.x capabilities such as Data Storage and the web-stack.

Strangely, for me it's the awesome testing chapter that brings the most value; testing reactive applications is just plain hard, and you'll really appreciate this chapter!

Its an absolute privilege and pleasure to have read this book, even if it reminded me of where wed gone wrong in a few places! Not to worry, though; we took Vert.x along with us when we got acquired by Microsoft, and this book will be the perfect companion to help us complete our story on a truly global scale.

Martijn Verburg--The Diabolical DeveloperPrincipal SWE Group Manager (Java)--Microsoft

I remember sitting in a comfortable cinema room at Devoxx Belgium 2012. Among the many conferences that I had planned to attend was one with Tim Fox introducing his new project called Vert.x. At the time, Node.js was all the hype, returning to asynchronous programming as the magic solution to all scalability problems. Through his presentation, Tim convinced me (and many other attendees) that he had just laid down a solid foundation for asynchronous programming on the JVM, embracing the strength of the Java ecosystem and picking the good ideas from Node.js. One thing that struck me at the time was that you could write simple Java code, and forget complex annotation-based frameworks and application servers. Vert.x felt like a breath of fresh air, so I kept an eye on the project. Fast-forward a few years: I am now working in the Vert.x team at Red Hat, something I wouldnt have imagined back in 2012!

Vert.x is increasingly relevant in an era when applications are deployed to virtualized environments and containers. We expect applications to scale up and down to accommodate fluctuating traffic. We expect applications to have low latency. We expect applications to be resilient when other systems fail. We expect to pack as many applications as possible onto a given server. In short, we need resource-efficient, scalable, and dependable applications.

This is what reactive applications are all about: latency is under control both as the workload grows and when failures happen. Vert.x is a solid foundation for building such reactive applications, but Vert.x alone is no silver bullet. You dont build reactive applications by taking a software stack off the shelf; you also need a methodology as you architect and develop a reactive application.

In this book we will explore how to write reactive applications with Vert.x. This is not just about learning Vert.x, but also the fundamentals of asynchronous programming and techniques to assess whether an application is truly reactive or not. Last but not least, Vert.x is fun, and you will see that this simplicity and forgetting about some supposed best practices can be liberating.

My first thanks go to my partner Marie and my son Mathieu for their incredible support. Writing a book takes some time away from your family, and I am very lucky to have them by my side.

I am grateful to be working with exceptional people at Red Hat. Thanks to Mark Little, David Ingham, Rodney Russ, and Julien Viet who gave me the opportunity to first take a sabbatical to work on Vert.x with Red Hat, and then to move to a full-time position. Many thanks to my closest colleagues Julien Viet, Thomas Segismont, Clment Escoffier, Paulo Lopes, Rodney Russ, Stphane pardaud, and Francesco Guardiani: working with all of you is a privilege.