We have gone through a few definitions of microservices; now, let's discuss microservices in detail.
In short, a microservice architecture removes most of the drawbacks of SOAs. It is more code-oriented (we will discuss this in detail in the coming sections) than SOA services.
Slicing your application into a number of services is neither SOA nor microservices. However, combining service design and best practices from the SOA world along with a few emerging practices, such as isolated deployment, semantic versioning, providing lightweight services, and service discovery in polyglot programming, is microservices. We implement microservices to satisfy business features and implement them with reduced time to market and greater flexibility.
Before we move on to understanding the architecture, let's discuss the two important architectures that led to its existence:
- The monolithic architecture style
- SOA
Most of us would be aware of the scenario where, during the life cycle of an enterprise application development, a suitable architectural style is decided. Then, at various stages, the initial pattern is further improved and adapted with changes that cater to various challenges, such as deployment complexity, large code base, and scalability issues. This is exactly how the monolithic architecture style evolved into SOA, further leading up to microservices.