I can imagine that the probability of this happening is higher than when you run without docker. But on the other hand you have mechanisms like sharding and rep

I can imagine that the probability of this happening is higher than when you run without docker. But on the other hand you have mechanisms like sharding and replications to deal with single machine/zone failure. I have run database clusters on kubernetes in production without running into this particular problem. The current state of container orchestrators for running databases is not optimal because one size does not fit all database types like with stateless applications. One solution for this problem are coreos operators which introduce third party resources into kubernetes that are specific to the database type and contain logic to manage this specific database type on kubernetes.