I’ know it’s perhaps too late but you might be interested in a few articles about “server” management
I generally advise to test these upgrades on separate infrastructure (I usually do that for major upgrades, but lately we had several issues with minor upgrades too, I’m pushing for that too)
So making a backup of the db and the war file before proceeding is the minimum before launching an upgrade.
For your problem, tomcat can be in to an unknown state
- I would check the logs (if the new version didn’t get hot reloaded by tomcat)
- I would check if some 2.39 2.40 migrations were not launched already (there’s a flyway table that logs them) How to Fix this Error: HTTP Status 404 – Not Found for http://localhost:8081 on linux "When upgraded system to 2.39.2 from 2.35.1"" - #8 by Stephan_Mestach
- I would share the startup logs (especially if you find an exception/stacktrace/error)