How to do zero-downtime rolling updates for app with (long-lived) sticky sessions using containers
Your work load might not be a good fit for Kubernetes/containers ith its current architecture. The best way I can come up to solve this is it to move the state to PV/PVC and migrate the PV to the new containers so the new container can have state from the old session, now how to migrate the calls for that session to the proper node I'm not sure how to do that efficiently.
Ideally you would separate your data/caching layer from your service into something like redis and then it wouldn't matter which of the nodes service the request.