Understanding stateful applications on Kubernetes
Kubernetes provides excellent primitives for running both stateless and stateful applications, but stateful workloads have taken longer to mature on Kubernetes. However, in recent years, some high-profile Kubernetes-based stateful application frameworks and projects have proven the increasing maturity of stateful applications on Kubernetes. Let's review some of these first in order to set the stage for the rest of the chapter.
Popular Kubernetes-native stateful applications
There are many types of stateful applications. Though most applications are stateful, only certain components in those applications store state data. We can remove these specific stateful components from applications and focus on those components in our review. In this book, we'll talk about databases, queues, and object storage, leaving out persistent storage components such as those we reviewed in Chapter 7, Storage on Kubernetes. We'll also...