Say I have a pico cluster with a few service nodes and a few upstream clients register themselves, and then I deploy a new version of the service nodes where all existing service nodes are taken down and replaced.

Can the client still talk to the service nodes? Is this over the same tunnel, or does the agent need to create a new tunnel? What happens to requests that are sent from a proxy-client to the service nodes during this transition?

Or at a much higher level: Can I deploy new service nodes without downtime?