[arch-general] Making pacman check multiple repos

[Brendan Long]

On Sun, 2009-12-13 at 11:16 +0800, Ng Oon-Ee wrote:
> On Sat, 2009-12-12 at 17:08 -0700, Brendan Long wrote:
> > 2009/12/11 Ng Oon-Ee <ngoonee at gmail.com>
> > 
> > > On Sat, 2009-12-12 at 02:13 +0100, Heiko Baums wrote:
> > > > Am Sat, 12 Dec 2009 08:58:17 +0800
> > > > schrieb Ng Oon-Ee <ngoonee at gmail.com>:
> > > >
> > > > > Because sometimes all the mirrors listed in mirrorlist will not have
> > > > > the file, if its just been uploaded. Also not everyone stays
> > > > > up-to-the-minute with updates, judging by the "updated after a month"
> > > > > posts we see once in a while.
> > > > >
> > > > > I'm concerned about the last bit, if a package was just uploaded and
> > > > > only exists on one mirror, everyone who updates and has that package
> > > > > in the period between its uploading and its appearance on their local
> > > > > mirrors will 'fall-back' on varying mirrors (lengthening the update
> > > > > process) and all end up on the poor main server (or Tier 1/2 mirrors).
> > > > > Bad for both the mirror bandwidth as well as most probably much slower
> > > > > for the user, who could probably just wait a day or so for the update
> > > > > to come to his (faster, presumably) local mirror.
> > > >
> > > >
> > > > Wouldn't it be possible to first upload the packages and update the db
> > > > files when the packages on the mirrors (at least on several mirrors)
> > > > are updated?
> > > >
> > > > If I have such a "problem" that a package is on no mirrors, which
> > > > doesn't happen often, I usually abort the system update and wait one
> > > > day. I think that's the normal and easiest way of solving this issue.
> > > >
> > > > Greetings,
> > > > Heiko
> > >
> > > The few mirrors which sync first would have quite much higher bandwidth
> > > usage =).
> > >
> > > The concern then is that in the period of time between uploading of
> > > packages and updating of db, the db would point to a package (foo-1.3)
> > > while the mirror would only have the new version (foo-1.4), since I
> > > don't think many mirrors keep multiple copies of the same package
> > > (schlunix I know off, any others?). So that would break updating as
> > > well, just in a different direction, and this would not be recoverable
> > > from.
> > >
> > >
> > Maybe a better idea would be to make pacman keep track of the last time it
> > got an updated package list, and if it's beyond a certain point, it starts
> > checking other mirrors (maybe optional "No updates have been found in 5
> > days, would you like to scan other mirrors for updates?").
> 
> The difference I would see is that in the current system an out-of-date
> mirror is still use-able (no mismatch between db and package as we're
> discussing). Some would manually change mirrors, but others would not,
> so the net effect of automating fallover would be to increase load above
> what it currently is.
> 
> Not everyone needs packages right on the day they're uploaded, or runs
> pacman everyday (I do, though =p)
> 

Not everyone runs pacman every day, but when you do, you expect to get
up to date packages.