caching packages on koji builder

[Mike Bonnet]

On Wed, 2008-11-05 at 09:49 -0600, Jason L Tibbitts III wrote:
> >>>>> "MB" == Mike Bonnet <mikeb at redhat.com> writes:
> 
> MB> Koji builders have never downloaded packages via XMLRPC.  All
> MB> downloading is done by mock/yum, via http (previously nfs).
> 
> Well, mock can cache all sorts of things these days.  If there are
> multiple builders at one location then having a single squid cache for
> them all might be nice, but mock's caching would still help to avoid
> having to hit the network.

Actually mock's caching doesn't really help us.  It's all done
per-buildroot, and since every build is run in a different buildroot,
the caches would never be reused.  For this reason Koji disables caching
in the mock configs it writes out.

A global (per-machine) rpm cache might be useful for reducing network
bandwidth.  However, because mock/yum would have to lock this global
cache while interacting with it, it would become a bottleneck when
running concurrent builds.  The best approach currently is probably a
local squid cache.