[davismwfl]

Can you or someone else elaborate on what issues you run into when running a database within Kubernetes? To be transparent, I have always ran my databases on dedicated or on AWS instances. I am interested in understanding what specific issues you have seen running DB instances within Kubernetes.

[extra_rice]

For the specific incident I mentioned in the original post, I didn't quite get the exact details of the problem, but I think the gist of it was that our MongoDB deployment was using too much memory for its cache. We're running it on our Kubernetes cluster that use M5.xlarge EC2 nodes, and it was causing problems to other applications deployed on the same node. Kubernetes was, understably, having a hard time managing resource and scheduling the deployments.

I think one of the challenges with running databases on Kubernetes is that, at the time of writing, Kubernetes does not really have an abstraction for databases and so it manages them just like any other resource (of a given type). Operators are meant to address this though, and the people at Kubecon seem to be excited about it, but I haven't used it personally.