From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: bug#26201: No notification of cache misses when downloading substitutes Date: Mon, 20 Mar 2017 23:49:12 -0700 Message-ID: <20170320234912.46680062@khaalida> References: <20170320184449.5ac06051@khaalida> <144e9ba8-af93-fb18-d2b9-f198ae7c11e9@tobias.gr> <20170320195247.05f72fc9@khaalida> <8e7e07d1-563f-666f-2c32-2a772757c86f@tobias.gr> <20170320214809.466dc5fe@khaalida> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:48626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqDcM-0007m6-2N for bug-guix@gnu.org; Tue, 21 Mar 2017 02:50:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cqDcJ-0002VE-0S for bug-guix@gnu.org; Tue, 21 Mar 2017 02:50:06 -0400 Received: from debbugs.gnu.org ([208.118.235.43]:38942) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cqDcI-0002Uo-S2 for bug-guix@gnu.org; Tue, 21 Mar 2017 02:50:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1cqDcI-0000vl-Hd for bug-guix@gnu.org; Tue, 21 Mar 2017 02:50:02 -0400 Sender: "Debbugs-submit" Resent-Message-ID: In-Reply-To: List-Id: Bug reports for GNU Guix List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org Sender: "bug-Guix" To: Tobias Geerinckx-Rice Cc: 26201@debbugs.gnu.org On Tue, 21 Mar 2017 07:21:54 +0100 Tobias Geerinckx-Rice wrote: > > only if the download might be slow because [mirror.hydra] is having > > to pull from hydra.gnu.org. =20 >=20 > So to implement this, the client would need to display a =E2=80=98warning= =E2=80=98 > message or flag sent by the substitute server, to notify the user that > their download might be slower... sometimes... by an unknown amount... > possibly? Simply a notification that mirror.hydra doesn't currently have a cached version of the file and the download might be slower than normal would be fine. As-is, looking up and seeing download speeds that amount to less than 10% of one's normal bandwidth is a bit concerning since it would seem like there is a problem. In this case, Guix would be giving the user some notification that something /is/ out of the ordinary, and possibly save the user some effort trying to determine the cause of the slowdown. > But see, that wouldn't be true at all on my system (and surely > others), despite being set up nearly identically to Hydra. On the > other hand, my home download speed fluctuates wildly, even between > simultaneous connections to the same server. I'm not sure how any of this matters. If you are running a local Hydra instance or whatever, then I'd assume you'd be aware of what, if any, problems that could arise. In this case, I'd hope hydra would allow you to disable this feature. > Whether or not a file is cached makes no difference. To be told would > be noise at best, is leading at worst. Had I been notified that mirror.hydra was currently pulling from hydra, it would have saved me the time of jumping on IRC and asking what was up, which only worked because someone was in #guix and had an idea of what was going on; had that not been the case, I would have started looking for the cause for the slowdown and wasted several minutes (at least) trying to figure out what was wrong, and since it was on mirror.hydra's end, I'd have no way to know the slowdown was on their end and not mine, nor my ISP's problem. > > AFAIK, Guix devs are working on a replacement for the current build=20 > > system, so the sane option wouldn't be extending the current hydra=20 > > system to handle a new API call, but to try and work this type of=20 > > feature into the next system. =20 >=20 > My point is that it wouldn't be sane, and would be an ugly hack in > either system. I don't see how this would have to be "an ugly hack". It's simply a query and response. The simplest way I can see for this to work would be for mirror.hydra to either just send the requested file, or a response that the file isn't cached then start to trickle the file on to the client.=20