[gwking]

It seems to me that you need to think about your server as the production database, rather than a web server instance that can be trivially spawned by a management layer.

When I deploy a new version of my python/sqlite web app, I do not replace the whole machine. I just upgrade the python package and restart the systemd service.

If I wanted to reduce downtime I could probably figure out a transition using SO_REUSEPORT. During the transition the old and new processes would be using the db concurrently, so the app would have to respect that case. If part of the upgrade requires a db schema change then I’m not sure how you could avoid some downtime. But I don’t know if it is possible with traditional dbs either.