From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tobias Geerinckx-Rice Subject: bug#26201: No notification of cache misses when downloading substitutes Date: Tue, 21 Mar 2017 04:57:09 +0100 Message-ID: <8e7e07d1-563f-666f-2c32-2a772757c86f@tobias.gr> References: <20170320184449.5ac06051@khaalida> <144e9ba8-af93-fb18-d2b9-f198ae7c11e9@tobias.gr> <20170320195247.05f72fc9@khaalida> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Ci71Ap23b3k0qo0Vex16PJ0aN6XRu8WjD" Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:35021) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqAuw-000092-Ur for bug-guix@gnu.org; Mon, 20 Mar 2017 23:57:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cqAut-0007BI-2t for bug-guix@gnu.org; Mon, 20 Mar 2017 23:57:07 -0400 Received: from debbugs.gnu.org ([208.118.235.43]:38904) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cqAus-0007Ae-Vw for bug-guix@gnu.org; Mon, 20 Mar 2017 23:57:03 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1cqAus-0005Iv-In for bug-guix@gnu.org; Mon, 20 Mar 2017 23:57:02 -0400 Sender: "Debbugs-submit" Resent-Message-ID: In-Reply-To: <20170320195247.05f72fc9@khaalida> 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: dian_cecht@zoho.com Cc: 26201@debbugs.gnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Ci71Ap23b3k0qo0Vex16PJ0aN6XRu8WjD Content-Type: multipart/mixed; boundary="8LfU2BlEuEaS6sf37mggES7AMiMmrLPCs"; protected-headers="v1" From: Tobias Geerinckx-Rice To: dian_cecht@zoho.com Cc: 26201@debbugs.gnu.org Message-ID: <8e7e07d1-563f-666f-2c32-2a772757c86f@tobias.gr> Subject: Re: bug#26201: No notification of cache misses when downloading substitutes References: <20170320184449.5ac06051@khaalida> <144e9ba8-af93-fb18-d2b9-f198ae7c11e9@tobias.gr> <20170320195247.05f72fc9@khaalida> In-Reply-To: <20170320195247.05f72fc9@khaalida> --8LfU2BlEuEaS6sf37mggES7AMiMmrLPCs Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Ahoy, On 21/03/17 03:52, dian_cecht@zoho.com wrote: > The URL displayed during the download was mirror.hydra.gnu.org. > [...] It was a binary download, not source. Oh, OK. I'm not an expert on how Hydra's set up these days, but will assume it's not too different from my own (a fast nginx proxy_cache, mirror.hydra.gnu.org, in front of a slower build farm, hydra.gnu.org). Whenever you're the first to request a substitute, mirror.hydra.gnu.org transparently forwards the request to hydra.gnu.org. The latter has to compress the response on the fly, leading to much slower transfer speeds. It slowly sends it back to the mirror, which slowly sends it on to you while also saving it on disc so all subsequent downloads will be fast =E2=80=94 by Hydra standards =E2=80=93 and not inv= olve hydra.gnu.org. Maybe you knew all this, but it's also the reason that... > On 21/03/17 02:44, dian_cecht@zoho.com wrote: > It would be nice if there was some notification that a cache miss > happened and the download will likely be slow, otherwise a user might > wonder what problem there is with their connection. =2E..I'm afraid this makes no sense from guix's point of view. The term =E2=80=98cache miss=E2=80=99 here is an implementation detail of= our current Hydra set-up, not something guix can or IMO should care about. There are hundreds of reasons why your connection might be slow at any given time. Guix should just tell you so (it does), not guess why. Or worse: know. (But if others disagree, we'll have to extend the Hydra API to somehow relay this information to the client, in the spirit of the modern Web.) HTTP 200=C2=BD: OK, fine, but it's Going to Suck. T G-R --8LfU2BlEuEaS6sf37mggES7AMiMmrLPCs-- --Ci71Ap23b3k0qo0Vex16PJ0aN6XRu8WjD Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEqBAEBCgAUBQJY0KSWDRxtZUB0b2JpYXMuZ3IACgkQkczbm0hUG5nmgAf/Z43j mtjWxZGLbwnEvaT8hnygDeUH3ml2BnOD52JaAAjVMbTwt9RsFdS1xq90hthza+bR HdWehFTg/W7gYvEh8qPPmdMV6mWdZTI0nMm8wSPX4dx9ljK9zrqLikaDPs+BeAsL K5AF8/rw9dhnfNBe6JK+eNtj6cmFI0L2J4RZmLyihz13NU58ojl+jrW9MBO2XB4l ZCBl8eDc9pBTTKfhWR9LueIJgdl9lDs0ZZeMksDNfZTnXiFQqHxiyGZzx7u8xjU/ StDjXiGB7p+UAiLbvvZxzEaFh8xBwoCkDqMl9J4aZN6+thLv5UTd8vDKqdkBwgNg AUKraRoPp3/RRL6E9g== =WI91 -----END PGP SIGNATURE----- --Ci71Ap23b3k0qo0Vex16PJ0aN6XRu8WjD--