> A distributed system with consensus will in practice provide higher availability than a single-node system, because it provides fault-tolerance.
I'm not sure this is true. It protects against one class of fault (node failure) but opens you up to another (network failure). As a distsys engineer I am increasingly convinced that fault tolerance is not a good selling point for distribution, the fallacies of distributed computing are real and difficult to accommodate.
That's not really true. With a single, non-replicated server, you're also very much exposed to network failures. If the server's connection goes down, you're screwed. Compare this to a Google replication setup of 2 East Cost, 2 West Coast, and 1 central USA server. The client must only be able to reach two out of three data centers (and they have to be able to communicate with each other). That sounds much more resilient to me - and I guess Google agrees, since they deploy the setup.
I'm not sure this is true. It protects against one class of fault (node failure) but opens you up to another (network failure). As a distsys engineer I am increasingly convinced that fault tolerance is not a good selling point for distribution, the fallacies of distributed computing are real and difficult to accommodate.