Spin up a second database VM and point a fresh frontend VM at it. Then atomically switch the frontend VM like I was describing before.
If that doesn't work come up with some kind, any kind, of rollback solution. There is no server problem that cannot have a rollback solution made for it.
Some places are cheap and would rather just upgrade in place in the middle of the night. Those places are cheap and bad at engineering. Do not work for or do business with them if you actually care about uptime.
If that doesn't work come up with some kind, any kind, of rollback solution. There is no server problem that cannot have a rollback solution made for it.
Some places are cheap and would rather just upgrade in place in the middle of the night. Those places are cheap and bad at engineering. Do not work for or do business with them if you actually care about uptime.