What should you name your hosts?
I used to believe this was an easy problem. Pick a theme, like Star Wars Characters or Constellations, and then name machines based on that theme: “chewbacca.tertiusfamily.net” for example. Use DNS CNAMEs to point your “functional” names (webapp1, or db1 or whatever) at the theme name and you’re off. Then I started working for Digg.
Digg’s infrastructure is massively horizontally-scaled. That means clusters, which means *lots* of individual nodes. No matter what “theme” you choose, you run out of names awfully fast. Not only that, but when you start building out a service-oriented architecture, you stop wanting to deal with individual nodes and start thinking in terms of clusters which provide services instead.
At the Puppet training I went to in Portland, we discussed the issue and I found out that there are two camps (well, as many camps as there are sysadmins, but it can be broken down into two camps). On the one side are those who want to put meta-data into their hostnames. On the other are those who think that hostnames should be as arbitrary as possible. There are strong arguments either way.
I think I come down firmly on the side of arbitrary hostnames. I’m coming to believe that, since IP addresses are necessarily unique, they should be the only unique identifier for an individual node. But I can’t come up with a solid argument as to why that is the best way.
What do you do about naming?