Re: pasta slow at HTTP upload

[Max Chernoff <git@maxchernoff.ca>]

Hi Stefano,

On Wed, 2025-11-12 at 11:32 +0100, Stefano Brivio wrote:
> Hmm, actually, I have a hack that's not quite correct (we should make
> ACK_INTERVAL adaptive instead, which is one of the other bits I'm
> working on), but if it fixes the issue for you, it should at least mean
> that we're talking about the same issue.
>
> Patch attached. Can you give that a try?

That seemed to help quite a bit---it's now 200x faster than before, but
still 10x slower than --network=host:

    $ curl --output /dev/null --progress-meter --form file=@./test.tar.gz "https://www.ctan.org/submit/validate"
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
    100  100M    0   345  100  100M     63  18.4M  0:00:05  0:00:05 --:--:-- 20.3M

    (With the original pasta, stopped early)
    $ podman run --rm --pull=newer --volume="$(realpath .):/srv/:Z" --workdir=/srv/ --network=pasta quay.io/fedora/fedora-minimal curl --output /dev/null --progress-meter --form file=@./test.tar.gz "https://www.ctan.org/submit/validate"
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      4  100M    0     0    4 5056k      0  78152  0:22:21  0:01:06  0:21:15 39298⏎

    (With the patch applied)
    $ podman run --rm --pull=newer --volume="$(realpath .):/srv/:Z" --workdir=/srv/ --network=pasta quay.io/fedora/fedora-minimal curl --output /dev/null --progress-meter --form file=@./test.tar.gz "https://www.ctan.org/submit/validate"
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
    100  100M    0   345  100  100M      8  2393k  0:00:42  0:00:42 --:--:-- 4729k

    $ podman run --rm --pull=newer --volume="$(realpath .):/srv/:Z" --workdir=/srv/ --network=host quay.io/fedora/fedora-minimal curl --output /dev/null --progress-meter --form file=@./test.tar.gz "https://www.ctan.org/submit/validate"
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
    100  100M    0   345  100  100M     69  20.0M  0:00:04  0:00:04 --:--:-- 20.4M

Also, I should mention that I'm using the following networking-related
sysctls:

    net.core.wmem_max=7500000
    net.core.rmem_max=7500000
    net.ipv4.tcp_notsent_lowat=131072
    net.core.default_qdisc=cake
    net.ipv4.tcp_congestion_control=bbr

I read some articles that suggested that those were a good idea, and
I've been using them for about a year now, but I can disable those for
testing if you want. I'm also using systemd's
IPAddressAllow/IPAddressDeny/RestrictAddressFamilies and some SELinux
port restrictions; I can easily disable those too.

Thanks,
-- Max