I can't for the life of me think of a compelling reason why regional fallover is something most companies would want in a db. It sounds great, but the reality is: the last time Azure had a regional failure, it also took down other regions. AWS and Google also have similar horror stories. On paper, regions are geographically isolated, but the reality is that in all of these instances of failure there was some "super-region" that has some core global infra that every region relied on, and it went down (AWS and us-east-1, Azure and south central US).
You don't actually want single-provider multi-regional, what you want is multi-provider, like what Anthos is trying to do. But that's a harder sell to CIOs, and Azure checks a lot of boxes on paper despite being just horrible.
The other funny thing about Azure is how they champion the number of regions they have (54), but many of these regions only have one AZ (only 8 have more than one). So when they say that something is multi-region or does regional fallover, its like, "great, that's TABLE STAKES for getting HA on Azure". But with AWS, you have at least two AZs in every region, so its not as big of a deal. GCP is the same way, but there's some language in their docs even AWS poked fun at during Re:Invent last year where they say that AZs "often" have isolated power and networking. Not always, just often. So are they truly isolated?
You don't actually want single-provider multi-regional, what you want is multi-provider, like what Anthos is trying to do. But that's a harder sell to CIOs, and Azure checks a lot of boxes on paper despite being just horrible.
The other funny thing about Azure is how they champion the number of regions they have (54), but many of these regions only have one AZ (only 8 have more than one). So when they say that something is multi-region or does regional fallover, its like, "great, that's TABLE STAKES for getting HA on Azure". But with AWS, you have at least two AZs in every region, so its not as big of a deal. GCP is the same way, but there's some language in their docs even AWS poked fun at during Re:Invent last year where they say that AZs "often" have isolated power and networking. Not always, just often. So are they truly isolated?