[mirror-admin] Mirror configuration and proxies caching yum metadata

[Chuck Anderson]

On Wed, Aug 06, 2008 at 08:48:12PM -0400, Warren Togami wrote:
> Matt_Domsch at Dell.com wrote:
>> I've received reports that caching proxy servers, those inbetween Fedora
>> public mirrors and Fedora end users, may be caching the yum metadata
>> (the contents of repodata/*) which then causes problems when the mirrors
>> update their content but the intermediate cache serves "stale" content.
>> As suggested by the OpenSUSE download redirector, I've added a section
>> to the recommended HTTPd config guidelines at
>> https://fedoraproject.org/wiki/Infrastructure/Mirroring#Caching_of_metad
>> ata
>>
>>
>> Caching of metadata
>>
>> We don't want caching proxy servers between our mirrors and our end user
>> systems to cache our yum repository metadata. So, add explicit metadata
>> handling. (Suggested by the OpenSUSE download redirector.)
>>
>>    <LocationMatch "\.(xml|xml\.gz|xml\.asc|sqlite)">
>>        Header set Cache-Control "must-revalidate"
>>        ExpiresActive On
>>        ExpiresDefault "now"
>>    </LocationMatch>
>
> It looks like the above is only for Apache proxy.  If you use squid  
> either as a transparent proxy or dedicated reverse proxy cache HTTP only  
> mirror, I have found the following to be especially good.
>
> refresh_pattern repodata/.*$    0       0%      0
> refresh_pattern images/.*$    0 0%      0
> refresh_pattern .*rpm$    0     0%      0

I assumed that the config above wasn't for proxies, but for mirror 
servers themselves.  Many of the transparent or regular proxies are 
run by ISPs, sometimes unbeknownst to the users.  In those cases, good 
luck getting the ISP to change their proxy config.  I hope that the 
mirror maintainers can mitigate that issue somewhat by implementing 
some changes server-side rather than proxy-side.

--