Fundamentals of Software Architecture, 2nd Edition

Chapter 9. Foundations

We know you are anxious to get to the details of architecture styles and patterns, but first we must cover some fundamental and definitional material to set the proper context for later chapters.

Styles Versus Patterns

We first need to distinguish between architectural styles and patterns in architecture, which are easily confused.

An architecture’s style describes several different characteristics of that architecture, including its:

Component topology

An architectural style defines how components and their dependencies are organized. For example, a layered architecture organizes component layers by their technical capabilities, whereas a modular monolith organizes its components around domains (more about this difference in “Architecture Partitioning”).

Physical architecture

Often, the style dictates the type of physical architecture: either monolithic or distributed. For example, a modular monolith is generally a monolithic architecture with a single database, whereas an event-driven architecture is always distributed.

Deployment

A system’s granularity and its deployment frequency are often associated with its architectural style. Teams generally deploy monolithic architectures as a single deployment along with a single relational database. Conversely, highly agile distributed architectures, such as microservices, feature automated integration, automated provisioning, and sometimes automated deployments; they are generally deployed in pieces, with ...