Re: package servers inconsistent?
Matt Zimmerman wrote:
>
> On Wed, May 02, 2001 at 10:33:27PM +0200, Harald Dunkel wrote:
>
> > Matt Zimmerman wrote:
> > > [...]
> >
> > Maybe its too difficult to provide consistent package files for the short
> > window while the mirror updates are running. No cons.
> >
> > But is it possible to set some kind of flag to indicate that I am probably
> > downloading just some inconsistent files and that I should wait till the
> > update of the mirror is complete? I have no problem with waiting, but
> > currently I can just try and check whether there was an error.
>
> It would be pretty simple to create a file to indicate this condition, which
> could be tested for when doing an update. However, I don't see how it would
> provide any additional information over the error messages from missing
> packages.
I guess it is obvious that downloading several MBytes to get an error message
is not very efficient. The bandwidth could be better used to speed up the
upgrade of your mirrors.
> After all, if the user's upgrade will only fetch a few packages,
> it's likely that the packages they want are already in place, and their upgrade
> would be successful (especially if these packages happen to fall at the
> beginning of the alphabet).
>
Like the XWindow packages? :-) Please remember that the complete upgrade
fails even if the very last package is missing.
> I disagree; a packages file (even without any associated .debs) is useful; it
> gives a list of packages, descriptions, dependencies, and other information.
> It can be used to determine whether there are any new packages to download, or
> to find whether a package exists. It would be annoying to lose this
> functionality during a mirror update.
Sure, but all this information is already in the Package files I have downloaded
from a consistent server on the previous run. The new Package files might
contain information about some *.deb files that I am not yet allowed to
download, which is very frustrating.
>
> What about stable? Removing the stable Packages file during an update would
> make it impossible to do a network install.
>
Not impossible. But the client would have to wait till the *.deb files have
been mirrored completely and the new Package files are in place again.
Removing the Package files is just one way to indicate that the mirror is
in an inconsistent state. As written before, I would suggest to set a
small flag file. If this file exists, then an mirror upgrade is running.
It even might contain a message to be displayed at the client.
Probably you haven't made the experience yet, what happens during the
upgrade over a small ISDN line (which is _not_ free here in Germany, even
if its a local call). Downloading the Package files takes about 4 minutes.
If I do an upgrade once per week, then I have to download (lets say)
50 MBytes or 150 packages, which takes about 2 hours. Currently I have
no way to check whether all *.deb files are available on the server,
i.e. I have to wait up to 2 hours for an error message.
Regards
Harri
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