Back Again

[Les Mikesell]

Tony Nelson wrote:

>> The annoying parts for me are that after finding the things I want, yum
>> repeats the metadata download for every install step and goes out of its
>> way to avoid allowing the site proxy cache from supplying it or the rpms.
> 
> Perhaps your yum is improperly set up.

Well, from my perspective (and I think for anyone with multiple machines 
behind a caching proxy) it is improperly designed.

 > Yum caches whatever it has
> downloaded before, but it can be configured to delete the cache upon
> sucessful installation (keepcache=0).

Yes, this is correct but it still insists on contacting every repository 
which has a significant time penalty even if you just did that seconds 
before. I assume it gets/parses/randomizes a mirrorlist for every 
repository before doing this check for new items that won't exist.

 > Yum defaults to spreading the load
> over all the mirrors by randomly choosing a mirror each time,

And it does this in a way that makes your proxy cache download a new 
copy for every request.

 > but it can be
> configured to use a baseurl list instead, which allows you to use the same
> mirror each time, with fallbacks when that mirror is not available.

Please translate that into the commands that people served by the same 
proxy should use to update their machines, keeping in mind that they may 
not know about each other or have anything else in common.  If that's 
not possible, translate it into what one user has to do to update 2 
machines, keeping in mind that yum was supposed to make things easier.

> In any event, yum does not normally ever reparse the metadata it downloads.
> That happens once, just after the data is downloaded, and not at all for
> the .sqllite files.  Perhaps using a proxy is your problem, or more likely
> an improperly set up proxy, as usually the worst that can happen is that,
> when the mirror one starts at is not fully updated, yum switches to another
> mirror for anything it needs that is missing, and sometimes that mirror is
> also not up to date but in different places.  I expect that a broken proxy
> setup could make this happen all the time.

I don't bother using a proxy except for Centos 3.x where the mechanism 
isn't broken.  It still takes much more startup time than a machine that 
uses apt-get.

-- 
   Les Mikesell
    lesmikesell at gmail.com