Eberhard Wolff - Microservices: Flexible Software Architecture

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Flexible Software Architecture

Eberhard Wolff

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ISBN-13: 978-0-134-60241-7
ISBN-10: 0-134-60241-2

Text printed in the United States on recycled paper at RR Donnelley in Crawfordsville, Indiana.

First printing: October 2016

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To my family and friends for their support.

And to the computing community for all the fun it has provided to me.

Although microservices is a new term, the concepts that it represents have been around for long time. In 2006, Werner Vogels (CTO at Amazon) gave a talk at the JAOO conference presenting the Amazon Cloud and Amazons partner model. In his talk he mentioned the CAP theorem, today the basis for NoSQL. In addition, he spoke about small teams that develop and run services with their own databases. Today this structure is called DevOps, and the architecture is known as micro services.

Later I was asked to develop a strategy for a client that would enable them to integrate modern technologies into their existing application. After a few attempts to integrate the new technologies directly into the legacy code, we finally built a new application with a completely different modern technology stack alongside the old one. The old and the new application were only coupled via HTML links and via a shared database. Except for the shared database, this is in essence a microservices approach. That happened in 2008.

In 2009, I worked with another client who had divided his complete infrastructure into REST services, each being developed by individual teams. This would also be called microservices today. Many other companies with a web-based business model had already implemented similar architectures at that time. Lately, I have also realized how continuous delivery influences software architecture. This is another area where microservices offer a number of advantages.

This is the reason for writing this booka number of people have been pursuing a microservices approach for a long time, among them some very experienced architects. Like every other approach to architecture, microservices cannot solve every problem. However, this concept represents an interesting alternative to existing approaches.