Automated test for upgrading BIND
suggestion - can we consider creating a test for updating BIND versions?
This will need to look at what persistent data needs to be preserved across the update. The complexity is that users update across multiple versions, perhaps the first scenario to address is migrating from the latest 9.11 version to the latest 9.16 version.
It might be good to measure how long the update takes, the time to reload (in case either of these are surprising that might indicate a problem), of course that bind restarts and reloads, maybe run a few queries??