#707672 promote debdelta to the official service

Package:
debdelta
Source:
debdelta
Description:
diff and patch utilities which work with Debian packages
Submitter:
ant
Date:
2013-11-23 08:42:07 UTC
Severity:
wishlist
#707672#5
Date:
2013-05-10 06:43:28 UTC
From:
To:
Dear Debian,

  At the end of a slow line it would still be nice to be able to download only
the actual binary differences between versions of a package during an upgrade.
Especially for larger packages.

  I'm sure it is possible to do technically, but it may require a very
different approach to packaging.

  For the longer view, yes, the internet is getting faster, but it isn't always
fast for everyone and it is nice to think of it as a limited resource.  If
Debian can make this change then that is many many bytes no longer needing to
be shipped, saving energy and connection times for everyone, disk space, etc.

  Thanks for consideration,

#707672#10
Date:
2013-05-10 06:47:04 UTC
From:
To:
This is already implemented, please install the debdelta package and
run debdelta-upgrade before apt-get upgrade/dist-upgrade.

#707672#13
Date:
2013-05-10 07:51:31 UTC
From:
To:
Control: reopen -1
Control: reassign -1 release-notes

As mentioned, this is already possible, but probably not documented
enough (or in the right place?).

Kind regards,
Andrei

#707672#22
Date:
2013-05-10 12:51:57 UTC
From:
To:
Hi,

Le 10/05/2013 03:51, Andrei POPESCU a écrit :

Is it just me, or both Paul and you misunderstood the proposal? It’s
about binary packages, not metadata if I understood correctly. Maybe
ftp.debian.org would be a more suited pseudo-package if so.

Regards

David

#707672#27
Date:
2013-05-10 17:50:39 UTC
From:
To:
Hi,

Le 10/05/2013 08:51, David Prévot a écrit :
just me, sorry.

debdelta is not really new, not sure the release-notes is the best place
to advertise it, maybe debian-reference would be better suited if not
already documented there.

Side note: it looks like apt-cacher-ng gain debdelta support in Wheezy,
so if someone propose a draft about it, maybe it could make it in the
“what’s new” section?

Regards

David

#707672#30
Date:
2013-05-10 19:58:43 UTC
From:
To:
Upgrading to a new stable release probably results in downloading an
order of magnitude more packages than all point releases combined. A
hint towards debdelta seems natural, maybe in the "sufficient-space"
section.

Kind regards,
Andrei

#707672#35
Date:
2013-05-11 08:44:37 UTC
From:
To:
Andrei POPESCU wrote:

Debdelta may be handy for Testing/Unstable users doing daily upgrades,
but I don't see how it's going to be any help for Stable users doing
biennial dist-upgrades.

Calculating deltas requires stored copies of the previous .debs to
diff against.  The http://debdelta.debian.net service keeps a set of
snapshots, but not 27 months worth: "Summarizing, an end user has a
window (of 10 to 50 days) of opportunity to upgrade using
debdelta-upgrade".

And what do I do with a downloaded delta if I don't have a local copy
of the old .deb to "patch" into the new version?

#707672#38
Date:
2013-05-11 17:24:17 UTC
From:
To:
Control: reassign -1 debian-reference

You're right, I didn't read up on how it works.

Kind regards,
Andrei

#707672#45
Date:
2013-05-13 12:18:48 UTC
From:
To:
Hi,
Are these DSA support?
Are these considered specialized mirror?

Regards,

Osamu

PS: For people on fast connection these days, the latency of getting
many diffs for package data is actually the slowing point.

#707672#52
Date:
2013-11-23 08:38:58 UTC
From:
To:
control: reassign 707672 debdelta
control: tags 707672 - moreinfo
control: retitle 707672 promote debdelta to the official service

Hi,

http://bugs.debian.org/707672

The original bug report to "general" can be understood as a request to
provide package download system already offered by debdelta.

It exists and looks like:

 # apt-get update && debdelta-upgrade && apt-get upgrade

But is not yet official part of the service.

http://debdelta.debian.net/html/index.html
| debdelta is an application suite designed to compute changes between
| Debian packages. These changes (that we will call 'deltas') are similar
| to the output of the "diff" program in that they may be used to store
| and transmit only the changes between Debian packages. This suite
| contains 'debdelta-upgrade', that downloads deltas and use them to
| create all Debian packages needed for an 'apt-get upgrade'.

It seems it is also facing technical challenges to be useful for the mass:

http://debdelta.debian.net/html/x182.html#the_enemy_within
| 4.4. better deb compression is a worse delta
| ...
|  In recent years, 'dpkg' has transitioned from 'data.tar.gz' to
| 'data.tar.bz2' to 'data.tar.lzma'; each method is better at compressing,
| but is also slower than the previous one; since it is better at
| compressing, it also defeats the ability of 'debdelta' to produce small
| deltas (wrt the original deb, of course), and indeed statistics show
| that deltas are getting larger; since it is slower, it slows down the
| applying of deltas as well.

After few bounces, this bug reached to my package "Debian Reference".
Considering the state of debdelta, I do not think it is within the scope
of information required to be included in "Debian Reference" as of now.

I am forwarding this bug to debdelta.  When it reaches enough maturity
and closes most of TODOs and BUGs:
http://debdelta.debian.net/html/x277.html
http://bugs.debian.org/cgi-bin/pkgreport.cgi?src=debdelta

Please prompt me to document this after it becomes part of the standard
apt archive.

Regards,

Osamu