[mikeyk]

You can hypothetically use something like hearbeatd to do it; we run every Redis master with an attached slave and manually failover for now.

For a small team like ours, we prefer solutions that are easy to reason about and get back into a healthy state (it would take one server deploy to point all appservers at new Redis master), rather than fully automated failover and the "fun" split-brain issues that ensue. Of course that may change as we build out our Ops team, etc.