On Mon, 2009 Aug 17 19:44+0100, Mark Hindley wrote:
>
> I meant, if you weren't using the path_map at all. Currently, if one
> apt client requests
>
> ftp.uk.debian.org/debian/pool/main/z/zip/zip_2.32-1_amd64.deb
>
> and one
>
> ftp.us.debian.org/debian/pool/main/z/zip/zip_2.32-1_amd64.deb
>
> through the same apt-cacher instance, it will return the same
> /var/cache/apt-cacher/packages/zip_2.32-1_amd64.deb to both clients.
> If you add the host/path prefix to the cached file, this will no
> longer happen. I am not convinced this is a corner case. Note that
> path_map is not enabled by default.
Ah, but look at it this way: If apt-cacher is being used as a proxy, why
should it presume those two .deb files to be equivalent? Say that
another client were to request
us.archive.ubuntu.com/ubuntu/pool/main/z/zip/zip_2.32-1_amd64.deb
As far as [the latest] apt-cacher is concerned, this URL is as similar
to the Debian URLs as the Debian URLs are to each other.
It comes down to an either-or of (A) redundant downloads when not using
path_map, versus (B) serving up a distro Foo package to a distro Bar
system. I think A is the lesser evil---and in absolute terms, it's no
worse than what Squid would do.
> The reverse of this is also problematic: You have
> /var/cache/apt-cacher/packages/zip_2.32-1_amd64.deb. In your 2 stage
> process to smooth the transition with existing caches, do you serve
> that as a debian or ubuntu file, assuming it existed in both distros?
The 2-step lookup is intended to allow existing caches and imported
packages to work as before the upgrade. There are more stringent
requirements for a cache to be able to serve multiple distributions
(there can't be any short-filename package files, unless they really are
bit-identical between distros), so more would have to be done to enable
that. (At worst, deleting everything from the cache; at best, analyzing
metadata to tell what package belongs to what distro, and renaming
accordingly.)
--
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
