From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#26201: hydra.gnu.org uses =?UTF-8?Q?=E2=80=98guix_?=
	=?UTF-8?Q?publish=E2=80=99?= for nars and narinfos
Date: Tue, 28 Mar 2017 16:47:14 +0200
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	<87r31pyms2.fsf_-_@gnu.org> <87inmzrgbf.fsf@netris.org>
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	Geerinckx-Rice's message of "Mon, 27 Mar 2017 20:47:17 +0200")
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To: Tobias Geerinckx-Rice <me@tobias.gr>
Cc: 26201@debbugs.gnu.org

Hey!

Tobias Geerinckx-Rice <me@tobias.gr> skribis:

> On 26/03/17 19:35, Tobias Geerinckx-Rice wrote:
>> I can try to do some simple tests tomorrow.
>
> Two observations:
>
> - =E2=80=98proxy_cache_lock_timeout=E2=80=99 alone won't suffice to seria=
lise requests;
>   =E2=80=98proxy_cache_lock_age=E2=80=99 must also be set to an equally r=
idiculously
>   long span. Otherwise, multiple requests will still be sent to =E2=80=98=
guix
>   publish=E2=80=99 if they are more than 5s apart. Bleh.
>
>   (The problem then becomes that clients will stall while the file is
>    being cached, as explained by Mark. curl patiently waited.)

Setting =E2=80=98proxy_cache_lock_timeout=E2=80=99 to 5s is reasonable I th=
ink: if
you=E2=80=99re unlucky, you wait for 5 seconds, and then we get =E2=80=98gu=
ix publish=E2=80=99
threads serving the same request in parallel; in the most common case,
there=E2=80=99s only ever one instance of a given request being served at a
given time.

> - Say client A requests a nar from =E2=80=98guix publish=E2=80=99 (no ngi=
nx involved).
>   If another client requests the same nar while A's still downloading,
>   =E2=80=98guix publish=E2=80=99 will... silently drop A's connection?
>   I was not expecting this.

That would be a bug.  Do you have an easy way to reproduce?

Thanks,
Ludo=E2=80=99.