Microservice apps, or simply microservices, is a method of developing software systems that tries on building single-function modules with interfaces and operations. The trend has grown popular in recent years as Enterprises look to become more Agile and move towards DevOps and continuous testing.
A Brief Introduction to Microservices Apps:
To start explaining the microservice style it's useful to compare it to the monolithic style. Enterprise Applications are often built in three main parts: a client-side user interface, a database, and a server-side application.
The server-side application will handle HTTP requests, execute domain logic, retrieve and update data from the database, and select and populate HTML views to be sent to the browser. This server-side application is a monolith - a single logical executable. Any changes to the system involve building and deploying a new version of the server-side application.
Microservices have many benefits for Agile and DevOps teams, as the examples mentioned in the end portion of this article. This makes changes to the application slow as it affects the entire system. A modification made to a small section of code might require building and deploying an entirely new version of the software. Scaling specific functions of an application, also means you have to scale the entire application.
Microservices solve these challenges of monolithic systems by being as modular as possible. In the simplest form, they help build an application as a suite of small services, each running in its own process and are independently deployable. These services may be written in different programming languages and may use different data storage techniques. While this results in the development of systems that are scalable and flexible, it needs a dynamic makeover.
Microservices are often connected via APIs and can attach many of the same tools and solutions that have grown in the RESTful and web service. Testing these APIs can help validate the flow of data and information throughout your microservice deployment.
Examples of Microservices Apps:
Netflix has widespread architecture. It receives more than one billion calls every day, from more than 800 different types of devices to its streaming-video API. Each API call then prompts around five additional calls to the backend service.
Amazon has also migrated to microservices. They get countless calls from a variety of applications, including applications that manage the web service API as well as the website itself, which would have been simply impossible for their old, two-tiered architecture to handle.
eBay is another example that has gone through the same transition. Their core application comprises several autonomous applications, with each one executing the business logic for different function areas.
Characteristics of Microservices Apps:
Software built as microservices can be broken down into multiple component services because each of these services can be deployed, and then redeployed independently without compromising the integrity of an application. As a result, we might only need to change one or more distinct services instead of having to redeploy entire applications.
Built For Business:
The microservices style is usually organized around business capabilities and priorities. Unlike a traditional monolithic development approach, where different teams each have a specific focus on databases, technology layers, or server-side logic.
Microservices act somewhat like the classical UNIX system, they receive requests, process them, and generate a response accordingly. This is the opposite of how many other products such as ESBs (Enterprise Service Buses) work, where high-tech systems for message routing, choreography, and applying business rules are utilized. You could say that microservices have smart endpoints that process info and apply logic.
Since microservices involve a variety of technologies and platforms, old-school methods of centralized governance aren’t optimal. Decentralized governance is favored by the microservices community because its developers strive to produce useful tools that can then be used by others to solve the same problems.
Microservices are designed to cope with failure. Since several unique and diverse services are communicating together, it’s quite possible that a service could fail, for one reason or another.