antonvs parent
It’s not just about bare metal or not. The sort of distributed systems these patterns apply to are not small local clusters in a single datacenter.
And the really big ones do much more epic clock management, and keep things wildly in sync across the globe. See the recent work with PTP that fb and others are trying to do openly. Google and others have their own internal implementations.
In the cloud, you have very little control over the clocks. If you have baremetal, there's almost always the ability to configure (at least) GPS time sync for a server or two. If you get to the point where you have entire datacenters, there's no excuse NOT to invest in getting good clocks -- and is likely a requirement.
"Not bare metal" does not imply "the cloud". You might be part of a company that doesn't give teams access to raw servers, you might be paying for VMs with dedicated resources from a local data center, or any number of other situations.
Not everyone has the luxury of being able to procure and install hardware and/or run an antenna to someplace with gpc reception.
I’d call that a “private cloud” and I think that’s the actual term for it. You can run a private cloud on bare metal, and if you are, then you can (as in physically able to) have control over things. If you have network cards with timestamp support, you can use PTP, or any number of things. If your org doesn’t support that, that doesn’t mean it isn’t a possibility, it just means you need to find someone else to ask.