[Yum-devel] Fastest mirror selection plugin

[Panu Matilainen]

On Wed, 16 Nov 2005, Luke Macken wrote:

> On Wed, Nov 16, 2005 at 11:11:47PM +0200, Panu Matilainen wrote:
> | Here's another variant of the plugin - this one figures out the fastest
> | mirrors before metadata download which makes quite a difference
> | especially on large updates:
> | http://laiskiainen.org/yum/plugins/fastestmirror/fastestmirror-meta.py
>
> Excellent -- I have been meaning to look into calculating the fastest
> mirror earlier on in the process for a while now... no free time.
>
> One minor issue with the code though; duplicate hosts still get added.

That's actually on purpose, duplicate hosts need to get added when they 
appear on different mirrorlists.

> As long as we're not modifying the timedhosts outside of the critical
> section (which we're not), then it's probably not a *huge* deal --
> worse case scenerio is that it looks for a duplicate host in the list
> while it is being added and doesn't find it?.  I'll leave it as-is for
> now, and look in to that a bit later.

I thought so as well, and at least in my tests the unprotected read 
accessses didn't seem to cause any anomalies, although that could be just 
pure luck :)

Next thing I have in mind wrt this is to add persistance - calculate the 
mirrors once and store them someplace and only recalculate every now and 
then, a simple approach would be "if the mirrorlist is older than a day or 
week" or something. Another thing I thought about is recalculate when 
network mask changes: desktops and servers typically don't much move 
around but a laptop can move around a lot and affect the optimal mirror 
selection.

 	- Panu -