From mboxrd@z Thu Jan 1 00:00:00 1970 From: Loic Dachary Subject: Re: Substriping support in ErasureCodeInterface Date: Fri, 05 Jun 2015 14:40:07 +0200 Message-ID: <557198A7.5040805@dachary.org> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="QfTfoctCst8B3dMAsiD9k380dAfvopa1A" Return-path: Received: from mail2.dachary.org ([91.121.57.175]:56882 "EHLO smtp.dmail.dachary.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751542AbbFEMkJ (ORCPT ); Fri, 5 Jun 2015 08:40:09 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Sindre Stene Cc: Ceph Development This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --QfTfoctCst8B3dMAsiD9k380dAfvopa1A Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi, On 05/06/2015 14:02, Sindre Stene wrote: > Is there, or is there planned support for substriping/subpacket support= in ErasureCodeInterface ? Not at the moment. > Clarification; I am looking for a way to test a different erasure codin= g scheme, that (in addition to having multiple stripes) has substripes wi= thin those stripes, letting us further reduce the amount of chunks retrie= ved from the HDD. I have an implementation ready in C for the encoder/dec= oder etc. I am looking to plug that into Ceph through the ErasureCodeInte= rface. https://github.com/ceph/ceph/blob/master/src/erasure-code/ErasureCodeInte= rface.h > The principles involved (which I am sure you are familiar with) are sim= ilar to https://research.facebook.com/publications/1445994382319911/a-hit= chhiker-s-guide-to-fast-and-efficient-data-reconstruction-in-erasure-code= d-data-centers/ , but with more substripes (>4, < 256). There is a declaration of intent for an hitchhiker plugin at http://track= er.ceph.com/issues/11268 but there is no progress yet. > Can it currently be done without having to modify the Ceph code base ? = (I am looking at master on ceph/ceph, and it seems to not be possible). > Could I ask you to link me to the appropriate issue tracker / Jira / fo= rum, if there is development going on already towards this goal?=20 Why do you think the current interface is insufficient ? What would you n= eed in addition ? Cheers >=20 > Sincerely, > Sindre B. Stene --=20 Lo=C3=AFc Dachary, Artisan Logiciel Libre --QfTfoctCst8B3dMAsiD9k380dAfvopa1A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iEYEARECAAYFAlVxmKcACgkQ8dLMyEl6F22k7gCcDUhRvi3DSlB7g+euLrrNscNF Tw4An14BQ98pdb+oTOMKwfxERwkmISxp =h8Q5 -----END PGP SIGNATURE----- --QfTfoctCst8B3dMAsiD9k380dAfvopa1A--