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by lobster_johnson 2960 days ago
I did describe both (Google could do a much better job with the integration on GCP/GKE), but by "Kubernetes first" I meant the latter.

Databases run fine on Kubernetes and have been doing fine since 1.7, and the meme that Docker is bad for stateful apps is a getting a bit old. The challenges are mostly the same as with running databases on a VM or bare metal. In particular, you need to know how to manage HA.

The weakest point is perhaps that Kubernetes's scheduler completely ignores disk I/O, so you have to bare careful to avoid sharing a node with multiple disk-heavy apps that will compete for resources. This is includes the file system cache; for example, PostgreSQL works best when it can rely on the OS to cache pages, so you don't want other apps (including Docker and Kubernetes themselves) to compete there.

That said, I wasn't saying that a hosted solution shouldn't also offer VMs. Just that Kubernetes should be the main entrypoint and control plane. And someone figured out a way to run VMs via Kubernetes [1], which is a neat example of a solution to the lack of integration I was complaining about earlier.

[1] https://www.mirantis.com/blog/virtlet-run-vms-as-kubernetes-...