[Yum] Yum speedup

[Brian Long]

>
>
>Personally, I'd propose a different approach. While up-to-date
>versions do really matter when I am fetching security updates, they
>are typically less important when doing an "install". It could be
>configurable, how frequently yum updates its cached lists, depending
>on the operation. For example, I could configure "every time" for
>"update", and "two weeks" for "install".
>  
>
This exists in some form in yum-2.4.2.  The metadata is cached by 
default for 2 hours, I believe.  I just got bitten by this last night 
while doing upgrade testing.  We integrate yum into our RHEL 3 / 4 
releases for internally-controlled updates.  Part of our yum-config RPMs 
point to versioned repositories.  For example, we have a version of 
Cisco Enterprise Linux based on RHEL 3 Update 5 and another upcoming one 
based on Update 7.  We have yum-config RPMs which point to different 
baseurl's depending on the release, but the repository names are the same.

While testing our update wrapper (which points you from one versioned 
release to the next), I found the metadata for the old version was being 
cached.  When I tried a "yum groupinstall", it was trying to used cached 
metadata for the RPMs contained in the group and those RPMs didn't exist 
because they had been updated out from under the cached data.  :)

/Brian/