Microservices describes the architectural pattern of composing a distributed application from separately deployable services that perform specific business functions and communicate over web interfaces. DevOps teams encapsulate individual pieces of functionality in microservices and build larger systems by composing the microservices like building blocks. Microservices apply an example of the open/closed principle: they are open for extension (using the interfaces they expose), and closed for modification (in that each is implemented and versioned independently).
Microservices provide many benefits over monolithic architectures. They can remove single points of failure (SPOFs) by ensuring issues in one service do not crash or impact other parts of an application. Individual microservices can be scaled out independently to provide additional availability and capacity. DevOps teams can extend functionality by adding new microservices without unnecessarily affecting other parts of the application.
Using microservices can increase team velocity. DevOps practices, such as Continuous Integration and Continuous Delivery, are used to drive microservice deployments. Microservices nicely compliment cloud-based application architectures by allowing software development teams to take advantage of several patterns such as event-driven programming and autoscale scenarios. The microservice components expose APIs (application programming interfaces), typically over REST protocols for communicating with other services.
An emerging pattern is to use container clusters to implement microservices. Containers allow for the isolation, packaging, and deployment of microservices, and orchestration scales out a group of containers into an application.
Microservices fundamental principles helped containers to prevail for the below reasons:
- Technology shift: Industry shifted from building server based JEE or .Net application on a heavy application server to stateless, immutable, scalable NodeJS or Springboot based microservices.
- Use & Throw: Agility in development requires speed to deploy, test & destroy. Containers are exactly enables that & easy to bring up & destroy.
- DevOps: Powerful tool to simplify the DevOps for microservices is containerization.
Now that it is evident that microservices architecture is the way forward and containerization is the enabler and DevOps is in the center focus to make the paradigm successful.
Microservices and DevOps are two important trends that have emerged in the enterprise are both microservices and DevOps. Both are practices that are designed to offer greater agility and operational efficiency.
Microservice architecture emerged from a common set of DevOps ideologies that came into being at companies like Amazon, Netflix, SoundCloud, Facebook, Google and several others. In many cases, those companies started with monolithic applications, which rapidly evolved into decomposed services, which then communicated via RESTful APIs and other network-based messaging protocols to become the harbingers of a microservices-based architecture.
Yet, the evolution of both microservices and DevOps was not just limited to transforming monolithic applications into decomposed services. Those companies that excelled at DevOps also shared common approaches to software development, had similar organizational structures and development cultures, while also sharing an affinity for cloud-based infrastructure and automation. Companies that have succeeded with microservices have followed a similar progression driven by a desire for development, speed, and scalability, all of which fits into the concept of agile development.
The rapid adoption of agile methods also fueled the growth of another concept well supported by a microservices based development cycle, Continuous Integration (CI). Those adopting CI have further leveraged agile ideologies to use microservices as a driver to achieve more frequent software releases, which has led to the practice of continuous delivery (CD). CD uses a quality focused ideology to build potentially shippable product increments, which speeds the deployment pipeline, achieving a result that culminates in bringing changes to production as quickly as possible.