Microservices offer a new way to architect and deploy enterprise applications. In microservices architecture, modular applications consist of small components or services that communicate and scale as needed. Microservices provide better scalability and use compute resources more efficiently than traditional software designs.
To understand microservices, it’s important to first understand traditional software models. Developers wrote traditional applications as a single, cohesive unit where every feature and function is contained within the same executable, dynamic link library or other active codebase. They would then provision a virtual machine or cloud instance with enough CPU and memory to operate the application. Then, the application is loaded onto the instance and started. This process works fine for many simple tasks.
But the problem — especially with enterprise-class, client-server applications — is that traditional application capabilities are finite. Developers design that software to provide only a limited amount of resources, such as simultaneous client connections. As the application encounters a processing, memory, I/O or other limit, its performance starts to decline and, in extreme cases, may crash. To work around bottlenecks, organizations need to provision and install another iteration of the application. This reduces the data center resources available for other tasks.
Think of traditional software design like building a house. The house is designed to hold a limited number of people and provide a finite number of services. Once you encounter a persistent bottleneck, you need a bigger house.
Software design has evolved to eliminate the bottleneck problem. Developers are increasingly segregating modern applications into separate components that use a common protocol, such as an API, to communicate and interoperate. Organizations deploy a microservices-based application as a series of interrelated components. The real power of this approach is that components are scalable; if a bottleneck occurs in one component, organizations can deploy more iterations of that component to handle the load.
A microservices architecture offers a scalable application design that uses resources more efficiently, and requires less overall compute power. In addition, microservices are an ideal complement to cloud services, such as event-driven and containerized computing.