Kubernetes cluster best practice

Question

I am working on a new project with Kubernetes and I need three environments: DEV,QA and PROD.

What is most recommended, create Multiple Clusters or create one big cluster separating environments by namespace.

Answer 1

Are you just going to have a single prod cluster or multiple prod clusters? One thing to consider is that updating the cluster management software (to a new k8s release) can impact your application. If you only plan to have a single prod cluster, I'd recommend running qa and dev separately so that you can upgrade those clusters first to shake out any issues. If you are going to have multiple prod clusters, then you can upgrade them one at a time to ensure application availability and sharing the clusters between environments makes a lot more sense.

Answer 2

Namespaces will not bring you isolation, at the moment it's just a different subdomain in dns. It's better to have namespace per application. I highly recommend you to have two clusters for prod (in case of updating k8s) and one-two for dev/qa.