Fundamentals of Software Architecture

Service-based architecture is also a natural fit when doing domain-driven design. Because services are coarse-grained and domain-scoped, each domain fits nicely into a separately deployed domain service. Each service in service-based architecture encompasses a particular domain (such as recycling in the electronic recycling application), therefore compartmentalizing that functionality into a single unit of software, making it easier to apply changes to that domain. Maintaining and coordinating database transactions is always an issue with distributed architectures in that they typically rely on eventual consistency rather than traditional ACID (atomicity, consistency, isolation, and durability) transactions. However, service-based architecture preserves ACID transactions better than any other distributed architecture due to the coarse-grained nature of the domain services. There are cases where the user interface or API gateway might orchestrate two or more domain services, and in these cases the transaction would need to rely on sagas and BASE transactions. However, in most cases the transaction is scoped to a particular domain service, allowing for the traditional commit and rollback transaction functionality found in most monolithic applications.