It depends on how downtime is defined in the contract.
That sounds like I'm being snarky but I mean it - whether an actual legal contract or just the documentation given to users, any system where downtime matters should have some discussion of what impacts downtime can have and how it's measured and managed.
That sounds like I'm being snarky but I mean it - whether an actual legal contract or just the documentation given to users, any system where downtime matters should have some discussion of what impacts downtime can have and how it's measured and managed.
That documentation is what defines "downtime".
I'll add that what you've described is a sort of low-fi manual version of DB replication (https://en.m.wikipedia.org/wiki/Replication_(computing)).