Tonight 'apt-get upgrade' offered 221MB of '.deb' packages, and quite
recently several prior versions of those same packages could be speedily
fetched by 'debdelta-upgrade', but tonight 'debdelta-upgrade' only
had 20K of new files. For some reason the debdelta server hasn't
had much new for the last few days.
Users then wonder if it's better to wait a while for the debdelta server
to update, or suffer through a longer download now. If delta
availability is like the weather, when will the weather change?
It'd be nice if in times of drought 'debdelta-upgrade' showed how
current the server was, and how often it gets updated, when it'll be
updated next, how much data it's slinging, etc.
(Better still would be apt server network idempotency, where no package
would be made available until every server had it, but that's another
kettle of fish...)
HTH...