[Beowulf] Configuration management tools/strategy

[Tim Cutts]

On 6 Jan 2013, at 18:55, Skylar Thompson <skylar.thompson at gmail.com> wrote:

> CFengine probably isn't a bad choice - going with something that's
> well-tested and -used is helpful because it's a lot easier to get
> recipes for what you need to do.

We use cfengine2 and cfengine3 here; still in the middle of migrating from one to the other.  We also evaluated puppet, at the time we were deciding whether to move to cfengine3.  Puppet vs. cfengine is very much another emacs vs. vi religious debate.  There are strengths and weaknesses to both, I think.  Puppet's manifest syntax is higher level and somewhat easier to get to grips with when you start, but anything more sophisticated and you have to start writing extensions in Ruby, and that language is one of my pet hates.  One thing some people may object to, which may or may not be because it's written in ruby, is the amount of RAM puppet uses while running.  Some might consider that to be unacceptably disruptive, depending on the size of your nodes and how fully utilised the RAM normally is.  CFengine's terminology is confusing.  Promisers and promisees; unnecessary terminology which just obfuscates things.  And easily typo'd one for the other as well.  But it does work, and it's relatively lightweight.  The commercial pricing, if you want the extra features that brings, is extremely expensive.  But I agree with Skylar, CFengine is well-established, and there's a lot of expertise out there.  Increasingly, that's true of the others as well, though.

> The one on the list I can absolutely
> recommend against is Spacewalk - we use RHN Satellite (the commercial
> version of Spacewalk) and it is easily the worst configuration
> management system I have ever seen.

We use another commercial version of Spacewalk, SuSE Manager, to manage patch levels on our SLES boxes.  We don't use it for any other distros, and not for configuration management other than patch levels.  It's not very pleasant to use, I agree - Fixing bugs in its scripts just to get it to install, and then fighting with Novell's hideous licensing model for it, took months.  Not pleasant.

For Debian and Ubuntu we use FAI for deployment, which works pretty nicely.  Obviously both cfengine and FAI config setups are under version control.

Tim

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