Fundamentals of Software Architecture, 2nd Edition

Chapter 20. Architectural Patterns

We distinguish between architectural styles and architectural patterns in Chapter 9: to recap, styles are named topologies that architects distinguish by differences in topologies, physical architectures, deployments, communication styles, and data topologies. Architecture patterns, inspired by the often-mentioned book Design Patterns, are contextualized solutions to problems.

It’s important to distinguish between architecture patterns and “best practices” (discussed in more depth in Chapter 21). Calling something a “best practice” implies that the architect has a clear duty, anytime a particular situation arises, to utilize that practice. Calling it a better practice would at least brook some argument, but no—we call it the best practice, allowing architects to shut off their brains and always follow the same solution.

It’s also important to distinguish between patterns and solutions. Many tools, frameworks, libraries, and other software-development artifacts encapsulate one or more patterns—depending on how they are implemented, with differing degrees of fidelity and intermingling with other patterns. Focus on identifying the most appropriate pattern first, then choose the most appropriate implementation for it.

We provide a smattering of representative patterns in this chapter to contrast and provide context for the styles we’ve introduced in Part II of this book. Our first example, an architecture reuse pattern, clarifies the difference between ...