Service-oriented architecture has been around for years now. The hype surrounding it in the past has finally waned, and we are now free to do real work and build real systems using it.

Do not mistake the lack of hype for a lack of relevance. If anything, SOA is more relevant than ever, as it’s practically the only good way to build cloud-based solutions (something I’ll discuss in chapter 10). Additionally, the SOA landscape has become more complicated over the years because SOA is now living side-by-side (or is integrated) with other architectures like event-driven architecture, REST, and big data (discussed in chapters 5 and 10).

SOA-related technologies are more mature now, but technology alone is not enough without proper architecture. That’s the main point behind this book: solving the architectural challenges of distributed systems in general and of SOA specifically by using architectural solutions expressed as patterns and antipatterns.

Roadmap

Part 1 of this book focuses on SOA patterns. It looks at ways to solve SOA challenges by using contextual solutions:

• Chapter 1 introduces SOA, its components, their relations, and the benefits of SOA. The chapter also introduces the concept of patterns and the pattern structure used in the book.
• Chapter 2 introduces some of the fundamental building blocks for building services.
• Chapter 3 tackles the core challenges of SOA, namely performance, scalability, and availability. These aspects are hard to get right because SOA adds latency by its very nature (because there are more components and distribution).
• Chapter 4 takes a look at different aspects of security and the management of services. Security is often a neglected part of any solution, and when we’re talking about SOA, which is composed of many services, this can prove to be a grave mistake.
• Chapter 5 covers the common interaction patterns for services, from the simple request/reply interaction to more advanced options.
• Chapter 6 looks at patterns for integrating services and service consumers, especially UIs that are not services in themselves.
• Chapter 7 takes a look at patterns that handle the composition and integration of services.

Part 2 focuses on different aspects of SOA in the real world:

• Chapter 8 introduces SOA antipatterns. These are some of the things that can go wrong when you implement SOA, and this chapter discusses how to redesign or refactor the solutions to solve the problems.
• Chapter 9 demonstrates, via a case study, how the different patterns can work together to create a greater whole—a complete system.
• Chapter 10 takes a look at additional architectures and technologies and how they work with SOA. Specifically, the chapter covers the REST architectural style, cloud computing, and big data.

SOA Patterns can be read cover to cover, but the discussion of each individual pattern and antipattern pretty much stands on its own and can be read for reference when you face a specific challenge. To help with that, the book includes an appendix that maps quality attribute scenarios back to individual patterns and helps identify patterns that are relevant to problems you face.

Who should read this book?

This is a book about service-oriented architecture, so it will appeal to anyone tasked with building a system based on these principles. It is also about building distributed systems in general, and I believe a lot of the patterns will appeal to a wide audience.

As its main concern is with software architecture, the book is naturally targeted at software architects. I’d like to think it’s also relevant for a wider audience, including developers who are tasked with building services and managers who want to understand the range of possible solutions.

The technology mapping sections of the book contain code excerpts mainly in C# and Java, but these are just examples and the designs are applicable in other languages. I’ve applied some of the patterns in projects that used Ruby and Scala and still found them relevant.