On Wednesday 17 August 2005 07:09, David N. Lombard wrote:
> >>2/ we need a mechanism to deal with packages at the cluster scale. That 
> >>means 
> >>find the best packages, construct a dependence tree between packages to 
> >>install at the cluster level, ...etc. This is the goal of depman/packman. 
> >>Unfortunately, the current version of Depman/Packman does not provide the 
> >>complete set of functionalities we need, and is not very useful (according 
> >>to 
> >>me).
> 
> Dependency resolution can only be done correctly against a target with 
> installed packages, i.e., an image that a node will be synced to, or 
> each node, independently.

Yes, but a cached dependency tree can exist for the packages you have in a
repository. Or the data for it, in a package-type independent format. See
below.

> > I believe Depman uses the update-rpms dependency tree implicitely. IMO this
> > should be only a workaround until we code cached dependency management which
> > is independent of the type of package.
> 
> Disagree. There is no reason for OSCAR to know anything about package 
> management or dependency resolution.  OSCAR only needs to know "what" 
> packages to install, not how or why.  I really don't care if update-rpms 
> is used or not; if update-rpms bothers you, replace it, say with yum. 
> Just don't build dependency resolution into OSCAR.

update-rpms doesn't bother me. It bothers me that we cannot use the nice
things in it like caching and dependency resolution for other packaging
systems. I don't want to build dependency resolution into OSCAR if the
infrastructure does what I need.

> > Because a dependency tree is a
> > dependency tree and doesn't need to know whether it deals with rpms or other
> > types of packages.
> 
> This confuses the near trivial effort to resolve dependencies with the 
> massive effort to collect the dependency information, which is strictly 
> dependent on the package system.  Any examination of update-rpms, yum, 
> apt, portage, or any other such system will reveal this.

Well, an examination of this lead to the conclusion that some of the package
management systems decided to use a common and independent way of caching the
package metadata: http://linux.duke.edu/projects/metadata
This works for both rpm and deb packages right now. I like it.

I played around with yum and createrepo and they almost provide what I was
asking for in the past email. They can manage several repositories and it was
trivial to build an image or install packages into an image.

What speaks against having a smart package management tool on the clients
(except that we don't have oscar-http yet)? And for installing/deinstalling
packages (also into images) and automatically resolving dependencies. Having
yum or update-rpms on the clients would make the Depman package unnecessary (I
think). Then you can _really_ eliminate the need for dependency info from
OSCAR.



> 
> > Here are two things we cannot do right now:
> > 
> > At some stage I would like to see that one master node can manage a RHEL, a
> > SLES and a Debian subcluster at the same time. From this follows a whish to 
> > be
> > able to deal with multiple package repositories, thus have several 
> > dependency
> > caches. 
> 
> Disagree. OSCAR should rely on the appropriate tools to do this.  On 
> Debian it's apt; on SuSE, SLES, Mandriva, Red Hat, Red Flag, CSC, et 
> al., it's some rpm super tool as rpm doesn't handle dependency 
> resolution beyond the packages identified on the command line.

Even if you disagree, I still think that managing a heterogeneous cluster is A
GOOD THING. I was actually asking for ideas for doing this (easilly).

> > Another whish: we should be able to upgrate images and installed nodes
> > in yum-like way, this means automagically, without having to deal with
> > dependencies.
> 
> Dependency resolution is exactly what yum provides...
> 
> > If possible, Packman/Depman should provide the infrastructure to
> > do this with any type of packages.
> 
> Disagree. Depman/Packman should rely on tools developed for the purpose 
> of resolving dependencies, like update-rpms, yum, apt, emerge, &etc.

I was thinking of using the update-rpms knowledge for creating a universal
tool. But yes, using high level package management tool below is another
solution. As said above, I'd prefer to see Packman::Yum or Packman::UpdateRPMS
and Packman::Apt instead of Packman::RPM. This makes Depman useless.

Regards,
Erich





-------------------------------------------------------
SF.Net email is Sponsored by the Better Software Conference & EXPO
September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
_______________________________________________
Oscar-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/oscar-devel

Reply via email to