Re: When substitute download + decompression is CPU-bound

[zimoun]

Hi,

On Thu, 28 Jan 2021 at 19:07, Ludovic Courtès <ludo@gnu.org> wrote:

> We could do that.  I suppose a possible agenda would be:
>
>   1. Start providing zstd susbstitutes anytime.  However, most clients
>      will keep choosing lzip because it usually compresses better.
>
>   2. After the next release, stop providing lzip substitutes and provide
>      only gzip + zstd-19.
>
> This option has the advantage that it wouldn’t break any installation.
> It’s not as nice as the ability to choose a download strategy, as we
> discussed earlier, but implementing that download strategy sounds
> tricky.

I propose to announce at the next release (v1.3) that strategy X will
be dropped at the next next release (v1.4), explaining the daemon
upgrade and/or point to documentation.

>From my understanding (thanks Guillaume for the plots!), X means gzip.
And we should keep lzip-9 (users with a weak network) et zstd-19, as
Pierre and Guillaume are proposing.

So gzip would stay until v1.4, i.e., more or less 1 year (or 1.5 years) more.


All the best,
simon