On Tue, Aug 30, 2016 at 3:11 PM, John Sanda <jsanda@redhat.com> wrote:

I like the idea of aggregated availabilities, but I don’t know that it can easily be simplified to up/down. Let’s say we have 3 Cassandra nodes deployed with replication_factor = 1. If one node goes down we are at 66% availability.

You're right, it would be even better to keep a "up ratio" information for each point. And it will still be easily reduced to a binary "all UP" or "any UP" by the client if desired.