On Wed, 13 Feb 2019 17:32:24 +0100 Julian Andres Klode <j...@debian.org> wrote: > Package: ftp.debian.org > Severity: wishlist > > > I'd like to reopen the discussion about the pdiff format on > the archive. Currently a pdiff is generated for each generation > of the archive, which means that apt has to fetch 4 pdiffs per > day it has to catch up. > > This means that for a 10 day interval, we have to fetch 40 pdiffs > per index. Assuming amd64+i386 with Contents files and Sources > enabled, we are looking at 2*(1+1+1)*40=6*40=240 files to fetch. > > This is clearly suboptimal, as it makes the log output unreadable, > and causes severe slowdowns on high-latency or non-persistent > connections. > > It might make sense to consider switching to merged pdiffs, which generate > one Pdiff from each generation to the latest one. This can be done either > by preserving old index files and creating pdiffs from them, or simply by > concatenating the new pdiff to the old ones. > > A point against it could be increased space requirements and time to > compress the pdiffs, but I'd welcome more discussion on that subject. > > -- > debian developer - deb.li/jak | jak-linux.org - free software dev > ubuntu core developer i speak de, en > >
On a related note, the last known blocker for #649882 is solved. If/when #649882 is implemented, we will have even more PDiffs by default for apt-file at the trade-off of making the Contents file smaller (particular multi-arch setups will benefit there). I suspect it will also off-set any grows in PDiffs being merged server side. Thanks, ~Niels
