zstd compression for packages

[Dimitri John Ledkov]

On 16 March 2018 at 22:13, Steve Langasek <steve.langasek at ubuntu.com> wrote:
> In other words: if we want to make this the default, we should quantify
> Daniel's remark that he would prefer a 6% faster download over a 10% faster
> unpack.
>

Well, I think it does not make sense to think about this in absolute
terms. Thinking about user stories is better.

A stable series user will be mostly upgrading packages from -security
and -updates. The download speed and/or size of debs does not matter
much in this case, as these are scheduled to be done in the background
over the course of the day, via unattended upgrades download timer.
Installation speed matters, as that is the window of time when the
system is actually somewhat in a maintenance mode / degraded
performance (apt is locked, there are CPU and disk-io loads).

New instance initialization - e.g. spinning up a cloud instance, with
cloud-init, and installing a bunch of things; deploying juju charm /
conjure-up spell; configuring things with puppet / ansible / etc =>
these are download & install heavy. However, users that do that
heavily, will be in a corporate / bussiness / datacentre environment
and thus it is reasonable to expect them to have either a fat internet
pipe, and/or a local mirror. Meaning download speed & size, are not
critical.

Then there are devel series users, developers who do sbuild builds,
etc. These users are most likely to be on slower home-user connections
and watch things a lot more closely interactively, who indeed care
about the total download+install time. These users, are most likely
very vocal / visible, but are not ultimately the target audience as to
why we develop Ubuntu in the first place. Thus I would be willing to
trade personal developer/devel-series user experience, in favor of the
stable series user. I'm not sure how much it makes sense to
proxy/cache/local-mirror devel series, if it is only a single machine
in use.

-- 
Regards,

Dimitri.

ps. I fight for the user
pss. /me goes to setup a local mirror proxy cache, with dns spoofing
to make sure all my sbuilds / lxd containers / VM / cloud-images use
local mirror out of the box