This looks interesting. At work we use a VIP to control which machines are in the live group and which are in the dark (standby) group. We used to use DNS, but the propagation delay caused issues, especially if we needed to roll back a change.
Doozer is a highly-available, completely consistent store for small amounts of extremely important data. When the data changes, it can notify
connected clients immediately (no polling), making it ideal for infrequently-updated data for which clients want real-time updates. Doozer is good
for name service, database master elections, and configuration data shared between several machines.