Understanding blue-green deployment concepts and patterns

Blue-green deployment is a practice that allows us to deploy a new version of an application in production without impacting the current version of the application. In this approach, the production architecture must be composed of two identical environments; one environment is known as the blue environment while the other is known as the green environment.

The element that allows routing from one environment to another is a router—that is, a load balancer.

The following diagram shows a simplified schematic of a blue-green architecture:

Figure 15.2 – Blue-green architecture

As we can see, there are two identical environments—the environment called blue, which is the current version of the application, and the environment called green, which is the new version or the next version of the application. We can also see a router, which redirects users' requests either to...