We have been developing different custom software for a long time and we are getting better and better at it. Dozens of technologies, architectural patterns, and all the best practices have been created. And microservice architecture (a.k.a. “microservices”) is one of those patterns which has emerged from the universe of domain-driven design, continuous delivery, scalable systems, infrastructure automation, and polyglot programming.
In a few words, microservice architecture is a kind of software development based on building single-function components.
For the first time, the term "micro web services" was used by Dr. Peter Rogers at a conference regarded cloud computing in 2005. However, microservices themselves debuted at a software architecture event in 2011, where the term was used to describe an architectural style that many participants were testing at the time. Amazon and Netflix were among the first users of microservices. What is more, Amazon prepared the ground for other companies by releasing a series of open-source solutions - AWS (Amazon Web Services) that are widespread now. And Netflix has built microservice high-load architecture based system for serving video service using Node.js.
The microservice approach is the contrast to the traditional monolithic architecture which consists of closely integrated modules that have to be scaled as a single unit while adding new features requires updating and reconfiguring everything from process and communications to security. It follows that monolithic software has long life cycles, is updated infrequently and changes usually affect the entire application. This pretty expensive and cumbrous process delays advancements and updates in custom software development.
Thus, although the monolithic approach works well for some enterprises and some software, microservice architecture is becoming more and more popular among companies that need better agility and scalability. The reason is that it was created to avoid problems of monolithic architecture because microservices break down complex tasks into smaller pieces, and they work independently of each other. In other words, the microservices style of architecture allows developing complex software from small, independent applications (let say units), that interact with each other using APIs, language-independent interfaces. And as an outcome, each unit can be updated, changed or deleted without disturbing the rest of the application.
Used efficiently, microservices allows scaling the application according to the number of developers working on your application. The key is to build applications without creating a complex, heavy formation at the macro level.
To sum it up, what are the benefits of a Microservices Architecture approach?
• Each particular component can be built in a different programming language, so you are able to choose the right tool for the right task.
• If one of the components fails, you can use another service and the application will continue to run independently.
• As this high-load architecture is based on small components, it’s much easier to scale the application following the requirements of a specific element.
• The development process becomes faster because you don’t have to change the codebase when modifying the features, but just change one component, test, and deploy it.
• For the same reason, debugging and maintenance become simpler.
Nevertheless, while many enterprises are rearranging their monoliths towards the microservices approach, that does not mean that microservices are perfect. This pattern isn’t always the best decision. The tight web of dependencies created by microservices can lead to some serious headaches. Obviously, there is no one true perfect way to design the software that everyone will always use. A lot of times the advantages of microservices outweigh the disadvantages, but sometimes it does not happen. Why?
• Microservices can cause some difficulties. While the complexity of a monolithic architecture lies in how complicated it can be to understand how different codes interact, Microservices’ complexity consists of having a lot of the code split out into individual services. Five-ten services aren’t so hard to manage, but thirty, forty or more, unfortunately, can be.
• Microservices require changes to the whole process and the culture of the company. If you are adopting microservice architecture, you will also need to adopt an agile workflow and also create a DevOps team.
• Microservices can be expensive. First of all, the costs of breaking up a monolith can cause additional, often not small, expenses. Besides, network calls made by APIs usually are not free.
• Microservices may cause some troubles with security. Each inter-network communication path raises a new security risk that needs to be monitored and resolved.
Taking into consideration all the aspects of the microservice approach, we can say that, although it’s not a panacea, all the benefits of microservices are really worth it for increasing numbers of modern organizations providing custom software development services. If development time allows, taking a microservices approach from the very beginning will save time and expenses of later refactoring. You could just consider all the pros and cons of consuming the time costs of starting with microservices versus delaying those costs towards the beginning with a monolith. The right answer will depend on the priorities of the company and the project itself.