Ask HN: Hostname Conventions for Distributed Systems?

I've gone through a variety of hostnaming strategies over the years, and the one I use now is <service><##> (eg zookeeper01).

With distributed systems in particular, but any system in general, boxes can come and go, and I hate having holes in my names (eg zookeeper01, 02, 04, 05, 06). That, and by choosing the number of leading zeroes, you're guessing at the max number of servers this service will be served by.

How do people manage this? I'm thinking something like <service>-<random_token> (eg zookeeper-fi2) would make sense and be more scalable, but I'm interested in what strategies other people use.

(I'd create a poll but I don't have the 200 karma) =/