Yum, Proxy Cache Safety, Storage Backend

[Les Mikesell]

Warren Togami wrote:
> On Wed, 23 Jan 2008 21:28:01 -0600, Les Mikesell <lesmikesell at gmail.com>
> wrote:
>> Warren Togami wrote:
>>
>>> Yum and Proxy Caches: Current Dangers
>>> =====================================
>>> Users may be using proxy servers in 3 (or more) ways:
>> Is there a reasonable way to make yum automatically use files cached in
>> these local proxies when run by multiple users that share the proxy but
>> don't know about each other?  Picking some random mirror for each will
>> defeat the caching since they will have different URLs to get the same
>> file.
> 
> http://fedoraproject.org/wiki/Infrastructure/Mirroring/SiteLocalMirrors
> This page needs updating, but it sort of describes what you need to do.

> Use your Fedora account to login to MirrorManager and add a private mirror
> for yourself along with a site-local netblock in CIDR notation so the
> mirror master knows to serve to you when yum clients come from your
> network.  After a few hours, mirror lists will serve your mirror first,
> then random other mirrors in your country/region.

Interesting, but it still requires custom setup for any distro/version 
that the proxy admin would want to support. What I'd really like to 
happen is for yum to just always prefer the same URL when working 
through the same proxy so caching would work by default without needing 
to be aware of the cache content.  This would work automatically if the 
target was a single site, RRDNS, or geo-ip managed DNS, but you probably 
can't arrange that for all the repo mirrors. There has to be some clever 
way to get the same effect even when using a mirrorlist - like making 
sure the mirrorlist itself is cached and always picking the same entry 
so any client will use the same URL that the mirrormanger gave to the 
first one that made a request.  Of course you'd need a reasonable retry 
mechanism to pick something else if this choice fails but I'd guess it 
would be a big win in bandwidth use and load on the mirrors if it worked 
most of the time to take advantage of existing local caches with no 
modifications.

-- 
    Les Mikesell
     lesmikesell at gmail.com