Microservices are intrinsically linked to cloud-computing platforms, but the actual concept of microservices is nothing new. This approach has been applied in the IT development world for many years, but now, through the popularity of cloud solutions, it has evolved to a higher level. It is not hard to point out the reasons for this popularity. The use of a cloud offers you scalability, reliability, and low maintenance costs in comparison with on-premises solutions inside the organization. This has led to the rise of cloud-native application development approaches that are intended to give you the benefits from all of the advantages offered by cloud-like elastic scaling, immutable deployments, and disposable instances. It all comes down to one thing—decreasing the time and cost that is needed to meet new requirements. Today, software systems and applications are being improved continuously. If you have a traditional approach to development, based on monoliths, a code base grows and becomes too complex for modifications and maintenance. Introducing new features, frameworks, and technologies becomes hard, which in turn impacts innovations and inhibits new ideas. We can't argue with that.
There is also another side to this coin. Today, practically everyone thinks about migration to the cloud, partly because it's trendy. Does everyone need this? Certainly not. Those who are not absolutely sure about migrating their applications to a remote cloud provider, such as AWS, Azure, or Google, would like to at least have an on-premises private cloud or Docker containers. But will it really bring them the benefits that compensate for expenses incurred? It is worth answering that question before looking at cloud-native development and cloud platforms.
I'm not trying to dissuade you from using Spring Cloud—quite the opposite. We have to thoroughly understand what cloud-native development is. Here is a really fine definition:
"A native cloud application is a program that is specifically designed for a cloud computing environment as opposed to simply being migrated to the cloud."
Spring is designed to accelerate your cloud-native development. Building an application with Spring Boot is very quick; I'll show you how to do this in detail in the next chapter. Spring Cloud implements microservice architecture patterns and helps us in using the most popular solutions from that field. Applications developed using these frameworks can easily be adapted to be deployed on Pivotal Cloud Foundry or Docker containers, but they might as well be launched in the traditional way as separated processes on one or more machines, and you would have the advantage of a microservices approach. Let's now dive into the microservices architecture.