Stateful Containerized Applications with Kubernetes


Stateless services are applications like web servers, proxies, and application code, which may handle data, but they don’t store it. These are easy to think about in an orchestration context because they are simple to deploy and simple to scale. If traffic goes up, you just add more of them and load-balance. More importantly, they are “immutable”; there is very little difference between the upstream container “image” and the running containers in your infrastructure. This means you can also replace them at any time, with little “switching cost” between one container instance and another.