Re: Offline use of apt-cacher
* Anuradha Ratnaweera [Mon, Jan 23 2006, 06:24:08PM]:
> - Lazy online: we like apt-cacher to fetch a Packages/Release file
> only if it old as set by a timeout. So if one runs apt-get update
> many times during a short period, only the first one will need to make
> a HEAD/GET request. (Lazy online has one tricky case if Packages file
> does get update before timeout, but that can be handled neatly and
> transparently as we are online).
Fine... but don't you describe what is said in the comments in
# apt-cacher can use different methods to decide whether package lists need to
# be updated,
# A) looking at the age of the cached files
# B) getting HTTP header from server and comparing that with cached data. This
# method is more reliable and avoids desynchronisation of data and index files
# but needs to transfer few bytes from the server every time somebody requests
# the files ("apt-get update")
# Set the following value to the maximum age (in hours) for method A or to 0
# for method B
So you basically want it to detect whether it's online and deliever the
old version if it's offline? That would be a bit uncomfortable in the
code because I would like to know up-front whether the file needs to be
refreshed or not. And how to detect the off-line status quick enough,
and not be confused with a timeout/slow server?
> This mode is going to be very useful when:
> - upgrading a large number of machines
> - running a script which _needs_ to run apt-get update many times
> (and it can't be rewritten to do it otherwise)
> - Offline: apt-cacher is totally offline. Files (Packages/Release
> files as well as DEBs) are served if available, and returns 503 if not
As said bvefore, if you activate this mode manually, this should be an
easy feature to add on. How do you want to configure it?
Major Krantz: What if we take you with us, put you on trial.
Zathras: Zathras not of this time. You take, Zathras die. You leave, Zathras
die. Either way, it is bad for Zathras.
-- Quotes from Babylon 5 --