From: Leo Famulari <leo@famulari.name>
To: Mark H Weaver <mhw@netris.org>
Cc: guix-devel@gnu.org
Subject: Re: Parallel downloads
Date: Wed, 13 Nov 2019 13:25:55 -0500 [thread overview]
Message-ID: <20191113182555.GA3059@jasmine.lan> (raw)
In-Reply-To: <87pnhvda3z.fsf@netris.org>
On Wed, Nov 13, 2019 at 11:16:53AM -0500, Mark H Weaver wrote:
> For these reasons, I'm inclined to think that parallel downloads is the
> wrong approach. If a single download process is not making efficient
> use of the available bandwidth, I'd be more inclined to look carefully
> at why it's failing to do so. For example, I'm not sure if this is the
> case (and don't have time to look right now), but if the current code
> waits until a NAR has finished downloading before asking for the next
> one, that's an issue that could be fixed by use of HTTP pipelining,
> without multiplying the memory usage.
>
> What do you think?
I agree that parallel downloads is a kludge to work around the issue of
slow set-up and tear-down of our download code. Pipelining would help a
lot, and we could also profile the relevant Guile code to see if there
are any easy speedups.
This issue was actually discussed a year ago:
https://lists.gnu.org/archive/html/guix-devel/2018-11/msg00148.html
I'll quote Ludo's suggestion from then:
> I’d be in favor of a solution where ‘guix substitute’ is kept alive
> across substitutions (like what happens with ‘guix substitute --query’),
> which would allow it to keep connections alive and thus save the TLS
> handshake and a few extra round trips per download.
next prev parent reply other threads:[~2019-11-13 18:26 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 15:07 Parallel downloads Pierre Neidhardt
2019-10-31 16:18 ` Tobias Geerinckx-Rice
2019-10-31 16:48 ` Pierre Neidhardt
2019-10-31 18:01 ` zimoun
2019-10-31 18:09 ` Pierre Neidhardt
2019-11-03 14:48 ` Ludovic Courtès
2019-11-03 15:29 ` Pierre Neidhardt
2019-11-06 15:34 ` Ludovic Courtès
2019-11-06 16:08 ` Pierre Neidhardt
2019-11-09 17:40 ` Ludovic Courtès
2019-11-10 13:28 ` Pierre Neidhardt
2019-11-12 15:36 ` Ludovic Courtès
2019-11-12 15:59 ` John Soo
2019-11-12 16:48 ` zimoun
2019-11-13 7:43 ` Efraim Flashner
2019-11-13 11:26 ` zimoun
2019-11-12 17:44 ` Leo Famulari
2019-11-17 17:15 ` Ludovic Courtès
2019-11-13 16:16 ` Mark H Weaver
2019-11-13 18:03 ` Pierre Neidhardt
2019-11-13 18:25 ` Leo Famulari [this message]
2019-11-13 19:34 ` Pierre Neidhardt
2019-12-13 9:35 ` Pierre Neidhardt
2019-12-13 12:25 ` Brett Gilio
2019-11-17 17:52 ` Ludovic Courtès
2019-11-06 21:26 ` Bengt Richter
2019-11-01 10:06 ` Joshua Branson
2019-11-01 19:11 ` Pierre Neidhardt
2019-11-03 14:50 ` Ludovic Courtès
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