Software Architecture Patterns, 2nd Edition

Chapter 6. Microservices Architecture

Perhaps the biggest change in architecture since 2012 is the introduction of microservices. This trend-setting architecture style took the world by storm, similar to what service-oriented architecture (SOA) did back in 2006. Over the years we’ve learned a lot about this revolutionary (and evolutionary) architecture style and how it addresses many of the complex problems we face in developing software solutions. New tools, techniques, frameworks, and platforms have come about over the years that make microservices easier to design, implement, and manage. That said, microservices is perhaps one of the most complicated architecture styles to get right.

Basic Topology

The microservices architecture style is an ecosystem made up of single-purpose, separately deployed services that are accessed typically through an API gateway. Client requests originating from either a user interface (usually a microfrontend) or an external request invoke well-defined endpoints in an API gateway, which then forwards the user request to separately deployed services. Each service in turn accesses its own data, or makes requests to other services to access data the service doesn’t own. The basic topology for the microservices architecture style is illustrated in Figure 6-1.

Figure 6-1. The basic topology of the microservices architecture style

Notice that although ...