RPM Community Forums

Mailing List Message of <rpm-users>

RE: high performance computing, HA and RPM5

From: Wichmann, Mats D <mats.d.wichmann@intel.com>
Date: Mon 07 Dec 2009 - 16:58:15 CET
Message-ID: <FE028D69955796489B510CE43DBBE8037AC9AD4F@rrsmsx503.amr.corp.intel.com>


Fascinating topic.  I think jbj's deliniation
into package vs. config management is useful.
Without going into a massive discussion, not that
I'm necessarily competent to do so anyway, let me
pick just one item and worry at it, and see if I
can just irritate everyone :)


Packages as containers for immutable files is where package management "works".
The corollary is that mutable files, either through configuration/patch management,
or for files that aren't contained in packages, doesn't work very well with RPM.


On a shared-storage "cluster" - loosely used term, I mean
any set up where there are lots of "nodes" and few
corresponding humans to watch over things :) - you're
going to have some local stuff that you want to keep
small, and everything else gets pushed to the shared
storage. I think there's a lot of agreement that single-system-
image type solutions are a good way to go for the
"system" part, stuff that always has to be there for a
client to be useful.  But what is an "application"?  Is
it part of "system" because it's been been put into a
package and installed through the same package manager used
to  handle the base system part?  Or is an "application"
somehow different (this is, of course, an ancient argument
with no clear answer)?  

It you put a key application into shared storage because
either you don't want to dedicate the space locally or
just as likely want absolute control that the bits are
the same for everyone, then the app is effctively mutable - 
the bits might fit the definition of immutable from someone's
perspective, but not from the perspective of a node, which 
wouldn't be in control of the changes made (someone updates 
the package from somewhere else).   So if you're using an image,
does the image contain knowledge of accessing an app
on the share, whatever it may be, or not?  Locally
stored rpm metadata would seem to me to be a bad
way to refer to bits that are under someone else's
control. 


Is there a place in this for rpm?  Or is this picture
in the "doesn't work very well" part and we just stop
thinking about it?
Received on Mon Dec 7 17:02:46 2009
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