New capabilities, such as cloud deployment systems and Docker, make it possible to implement a new kind of service architecture. Docker makes it possible to define server process configuration in a repeatable container that's easy to deploy by the millions into a cloud-hosting system. It lends itself best to small, single-purpose service instances that can be connected together to make a complete system. Docker isn't the only tool to help simplify cloud deployments; however, its features are well attuned to modern application deployment needs.
Some have popularized the microservice concept as a way to describe this kind of system. According to the microservices.io website, a microservice consists of a set of narrowly focused, independently deployable services. They contrast this with the monolithic application-deployment pattern where every aspect of the system is integrated into one bundle (such as a single WAR file for a Java EE app server). The microservice model gives developers much-needed flexibility.
Some advantages of microservices are as follows:
- Each microservice can be managed by a small team.
- Each team can work on its own schedule, so long as the service API compatibility is maintained.
- Microservices can be deployed independently should this be required, such as for easier testing.
- It's easier to switch technology stack choices.
Where does Node.js fit in with this? Its design fits the microservice model like a glove:
- Node.js encourages small, tightly focused, single-purpose modules.
- These modules are composed into an application by the excellent npm package management system.
- Publishing modules is incredibly simple, whether via the NPM repository or a Git URL.
- While an app framework such as Express can be used with large services, it works very well for small lightweight services and supports easy, simple deployment.
In short, it's easy to use Node.js in a lean and agile fashion, building large or small services depending on your architecture preferences.
