Comments on: Naming Is A Hard Problem

By: Nathan Milford

Nathan Milford — Sat, 24 Apr 2010 02:03:23 +0000

For small environments I use Kurosawa films (yojimbo, rashmon, etc..), I’m a fan.

When I first started at outbrain the functionality of machines and what app was deployed on each one changed somewhat often. We had se1, be4, ofl2, api24 & mysql4 all running Solr at one point.

It was frustrating.

We’re moving to a generic host naming scheme that works thus:

ob + environment + last IP octet.

Where environment 1 is NYDC1 App VLAN,or 2 might be LADC2 Web VLAN.

So 192.168.252.4/24 is in our first NY Datacenter’s app VLAN so it’s hostname would be: ob1004.

Then I give it a cname related to it’s function like api*, mysql*, cass* and also I create a TXT record that a bash script grabs it’s prompt info from which ultimately looks like:

(ob1004)(nathan@ofl2:~)$

This makes it easy on the developers and Q&A folks who need to get on a specific machine and it makes it easy on me since I don’t need to change a mass of stuff if a machine’s purpose changes.

- n

By: plathrop

plathrop — Thu, 29 Jan 2009 01:43:54 +0000

I completely disagree with you here, actually. CNAMEs grant you a HUGE benefit when you want to move a service from one machine/cluster to another. Fail-over becomes as simple as updating the CNAME.

I used to follow the idea of functional names with meta-data until I started working on large-scale installations with a lot of re-purposing of servers.

By: plathrop

plathrop — Thu, 29 Jan 2009 01:41:26 +0000

But what do you do when you move the server to a different rack location? Or repurpose it from a app/dns/whatever to something else?

By: plathrop

plathrop — Thu, 29 Jan 2009 01:40:39 +0000

I like themes a lot, but I have definitely run into issues before. I think hostnames shouldn’t matter as much as they do.

By: egon

egon — Thu, 29 Jan 2009 00:06:29 +0000

I use arbitrary names for sets of machines that are distinct. Names of the moons of Jupiter, literature mentioned in “Ghostbusters”, interesting words from the dictionary…

For clusters or grids of machines, or pooled common machines, I use functional or positional names. app1,app2,appN : dns1,dns2, or r1p1,r1p2 for names of machines that fill up rack 1, all of which are in a common cluster or grid.

By: Nathan

Nathan — Wed, 28 Jan 2009 15:35:38 +0000

I work with a guy who uses names of Transformers.

By: jtimberman

jtimberman — Wed, 21 Jan 2009 01:06:28 +0000

I like being able to look at a hostname or fqdn and know what function that server provides, optionally which environment it belongs to. For example:

web1prod
web1.prod.example.com

For multiple customer systems in a hosted environment that have the same domain:

custid-web1prod
web1prod.custid.example.com

Etc.

I don’t like “theme” hostnames. They’re not useful, especially in an environment that has high sysadmin turnover or even growth, because then each new person needs to be trained to know that systems named after star wars planets are web servers and star trek races are database servers. “What does chewbacca do again?” Sure, CNAMEs can be used, but thats extra hassle for very little practical gain.

Instead, have fun with comments in your configuration code and git commit messages .