Presuming, of course, that your cluster is completely isolated from the outside world. Otherwise, the interaction of various controllers, deployment stacks, and

Presuming, of course, that your cluster is completely isolated from the outside world. Otherwise, the interaction of various controllers, deployment stacks, and application usage conspire to generate endless amounts of cluster state change requests, which can quickly pileup if etcd is unavailable or behaving erratically and cause all manner of havoc. Containers can fail to restart after crashing; jobs won't run, etc. Plus, in k8s etcd is typically used for more than just the barebones state required for basic node and pod status. Metrics, API requests, DNS, etc, often depend on etcd--the same etcd--for storage and communication, which can compound the effect of a flakey etcd and even instigate it.