>partial failure scenario, with a fully functional client-server connection but failed server-server replication connection, seems rare You're more likely to s

>partial failure scenario, with a fully functional client-server connection but failed server-server replication connection, seems rare You're more likely to see it when you are running services across multiple datacenters/availability zones/regions/whatever. It still happens frequently enough that it's a scenario worth keeping in mind. You probably have your application servers local to your database servers in that other datacenter, so if your public facing network falls over in a datacenter, there's probably still some amount of work happening that modifies things in the database - what happens when that connectivity is restored? Being able to gracefully handle network partitions is hugely important in distributed computing.