So you’re setting up a multi-region RDS. If region A goes down, do you continue to accept writes to region B?
A bank: No! If region A goes down, do not process updates in B until A is back up! We’d rather be down than wrong!
A web forum: Yes! We can reconcile later when A comes back up. Until then keep serving traffic!
CAP theorem doesn’t let you treat the cloud as a magic infinite availability box. You still have to design your system to pick the appropriate behavior when something breaks. No one without deep insight into your business needs can decide for you, either. You’re on the hook for choosing.
A bank: No! If region A goes down, do not process updates in B until A is back up! We’d rather be down than wrong!
A web forum: Yes! We can reconcile later when A comes back up. Until then keep serving traffic!
CAP theorem doesn’t let you treat the cloud as a magic infinite availability box. You still have to design your system to pick the appropriate behavior when something breaks. No one without deep insight into your business needs can decide for you, either. You’re on the hook for choosing.