Blue-green deployments represent a wise innovation on the part of system operators and engineering groups. The basic concept of a blue-green deployment is, in many ways, similar to the branching by abstraction concept we discussed earlier.
Blue-green deployments offer the idea of deploying a side-by-side instance of a component or application, all the while leaving the existing instance running and serving live traffic. When the deployment is deemed a success, traffic is flipped from the old version over to the new one. The following is a simple diagram illustrating blue-green deployments:
As we can see, new connections ...
