Dropping gzip-compressed substitutes?

Dropping gzip-compressed substitutes?

[Ludovic Courtès]

Hello!

I saw in the maintainer meeting minutes the point about substitute
compression.

Back when zstd substitutes were introduced, the idea was to “eventually”
drop gzip substitutes (lzip substitutes remain relevant⁰):

  https://lists.gnu.org/archive/html/guix-devel/2021-03/msg00333.html

It was too early back then but I think we could consider dropping it
after 1.4.0 is out, announcing it in advance.

To those users still running a pre-1.1.0 daemon lacking lzip support¹,
things will just break, or at least they won’t get newer substitutes.
It’s been almost 2 years since 1.1.0 was released though.

But there does seem to be users on foreign distros who never update
their daemon and don’t read news either.  We could have (guix store)
warn when it’s talking to an old daemon, which would give people a
reminder that they need to upgrade.  (That would only work for very old
daemons because the protocol version rarely changes.)

Thoughts?

Ludo’.

⁰ https://guix.gnu.org/en/blog/2021/getting-bytes-to-disk-more-quickly/
¹ https://guix.gnu.org/en/blog/2020/gnu-guix-1.1.0-released/

Re: Dropping gzip-compressed substitutes?

[Ricardo Wurmus]

Ludovic Courtès <ludo@gnu.org> writes:

> Hello!
>
> I saw in the maintainer meeting minutes the point about substitute
> compression.
>
> Back when zstd substitutes were introduced, the idea was to “eventually”
> drop gzip substitutes (lzip substitutes remain relevant⁰):
>
>   https://lists.gnu.org/archive/html/guix-devel/2021-03/msg00333.html
>
> It was too early back then but I think we could consider dropping it
> after 1.4.0 is out, announcing it in advance.

Sounds good to me.

> To those users still running a pre-1.1.0 daemon lacking lzip support¹,
> things will just break, or at least they won’t get newer substitutes.
> It’s been almost 2 years since 1.1.0 was released though.

I’ll admit that back then I had neglected to upgrade the shared daemon
at the MDC, missing the change to different compression types.  A
considerable chunk of the demand for gzip substitutes then could have
been due to the MDC.

Eventually, I did upgrade the shared daemon, so demand should have
dropped significantly.

> But there does seem to be users on foreign distros who never update
> their daemon and don’t read news either.  We could have (guix store)
> warn when it’s talking to an old daemon, which would give people a
> reminder that they need to upgrade.  (That would only work for very old
> daemons because the protocol version rarely changes.)

Printing a warning is a good way to get people’s attention, so I’m all
for it to prepare for the big break.

-- 
Ricardo

Re: Dropping gzip-compressed substitutes?

[Ludovic Courtès]

Hi!

Ricardo Wurmus <rekado@elephly.net> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:

[...]

>> It was too early back then but I think we could consider dropping it
>> after 1.4.0 is out, announcing it in advance.
>
> Sounds good to me.

The maintainers went ahead and announced it, thumbs up!  It might also
be worth emailing info-guix?

>> To those users still running a pre-1.1.0 daemon lacking lzip support¹,
>> things will just break, or at least they won’t get newer substitutes.
>> It’s been almost 2 years since 1.1.0 was released though.
>
> I’ll admit that back then I had neglected to upgrade the shared daemon
> at the MDC, missing the change to different compression types.  A
> considerable chunk of the demand for gzip substitutes then could have
> been due to the MDC.

I think it’s understandable; it’s an invisible component, after all.  A
few weeks ago I discovered that a colleague of mine was running
guix-daemon from 0.15.0…

> Printing a warning is a good way to get people’s attention, so I’m all
> for it to prepare for the big break.

Mathieu did that in f9c62b23cc88541756656b3ec602ce987828d906, which
should help!

Ludo’.