[Beowulf] anyone using SALT on your clusters?

[Paul English]

On Tue, Jun 25, 2013 at 5:27 AM, Eugen Leitl <eugen at leitl.org> wrote:

>
>
> http://blog.smartbear.com/devops/a-taste-of-salt-like-puppet-except-it-doesnt-suck/
>
> A Taste of Salt: Like Puppet, Except It Doesn’t Suck
>
>
We are using cf-engine (3) after a relatively brief dalliance with chef.
chef was very slow for our purposes, and ruby seems to be a slightly tidier
version of perl ie: not very tidy. It seemed to be a constant source of
cursing in the IT department.

cf-engine has made the IT team very happy.

Overall, I think the approach of using a configuration management system
for... configuration management seems to be the way to go. It is a
distribution-agnostic approach too.

ROCKS served us well for years, but being chained to the CentOS release
cycles (plus some additional delay) tended to hamper using newer hardware,
along with other problems. And on the whole, it tended to do a somewhat
poor and constrained job of what is essentially 'configuration management.'
Do we really want/need the master node to be a router to the rest of the
network? Well.. sometimes not. Do we really want/need the master node to be
the authoritative DHCP and DNS server for the cluster nodes? Maybe..
etc etc.

For shuffling data around and the equivalent of what Salt's original
purpose in life was, we use prsync and pssh. They work very well. We can
use them with canned lists of hosts (generated by cf-engine for this
purpose eg: all hosts of type X), with ssh keys etc. I suspect they are
slower and and perhaps less "something" (scalable perhaps? we are a
relatively small site in HPC terms) than Salt's ZMQ based approach. But
they've been good enough for what we've done so far.

I would suggest some caution when approaching Salt - which we did when we
were considering what to do after chef. While Salt seems to be an
exceptional approach to "do a bunch of things on a bunch of hosts," AND it
is in python (win!), it does seem that the configuration management part is
an add-on and/or afterthought. Yes - configuration management does involve
lots of doing lots of things on lots of hosts. But cf-engine is now in it's
third iteration of "what does that _mean_ in real terms - with tons of
different configuration 'languages', files, daemons, restart services etc..
even only on Linux?"
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