[Beowulf] anyone using SALT on your clusters?

[Joe Landman]

On 06/27/2013 09:02 PM, Mark Hahn wrote:
>>> why the big deal about cf-engine/salt/puppet/chef/etc?
>>
>> Well with xCAT (which we use) the big thing is node auto-discovery and
>> naming. If we physically replace a node we remove its MAC address from
>> xCAT and when we turn it on it boots into a discovery image, gets
>> named based on its switch port (via a system you define to it),
>> programs the BMC/IMM appropriately and then lights up its attention light.
>>
>> When we brought up our new Intel system recently we just plugged it
>> in, turned it on and waited for all the little blue lights to come on
>> to say it was appropriately configured. :-)
>
> sure, I like auto-configuring clusters too, but do you need salt-like
> tools for this?  the way I do it is that the pxe default boots into

No.

> the discovery kernel, which in rc.local just probes MAC/IPMI/port
> and hands it to the admin node, which updates the DB and switches pxe
> to a normal node boot.

Yup.  This is one of our operational modes.  Treat the hardware as code. 
  Just don't enforce language, objects, etc.  Most of that is not 
necessary and it gets in the way in many cases.

Its very easy to fall into the trap of building huge monolithic apps to 
perform what are effectively simple functions.  This is what anaconda, 
puppet, et al. do.  Debugging them and maintaining them becomes a hard 
problem, and there become more and more constraints around what is 
possible, in large part, due to the implementation (and sometimes 
language issues).

Salt and their ilk solve a set of problems.  We have customers using 
Salt.  And puppet/chef/... .  Many of these are opinionated frameworks. 
  Such frameworks are good for web development.  Maybe less so for 
cloud/cluster setup/use.


-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
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