From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcel Lauhoff Subject: Re: OSD-Based Object Stubs Date: Thu, 28 May 2015 12:01:54 +0200 Message-ID: <87617dc965.fsf@irq0.org> References: <87a8wqct38.fsf@irq0.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from cpu0.net ([37.187.2.217]:43769 "EHLO cpu0.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753684AbbE1KBw (ORCPT ); Thu, 28 May 2015 06:01:52 -0400 Received: from janelane.irq0.org (x5d82518d.dyn.telefonica.de [93.130.81.141]) by ks3366964.kimsufi.com (Postfix) with ESMTPSA id 6FDA78029A for ; Thu, 28 May 2015 10:01:50 +0000 (UTC) In-reply-to: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Gregory Farnum Cc: "ceph-devel@vger.kernel.org" Gregory Farnum writes: > On Wed, May 27, 2015 at 1:39 AM, Marcel Lauhoff wrote: >> Hi, >> >> I wrote a prototype for an OSD-based object stub feature. An object stub >> being an object with it's data moved /elsewhere/. I hope to get some >> feedback, especially whether I'm on the right path here and if it >> is a feature you are interested in. >> >> >> >> Code is in my "osd-stubs" branch: >> https://github.com/ceph/ceph/compare/master...irq0:osd-stubs >> https://github.com/irq0/ceph/tree/osd-stubs >> >> Tools to toy around with osd-stubs + web server to send stubs to: >> https://github.com/irq0/ceph_osd-stub_tools >> >> >> >> Related: >> - https://wiki.ceph.com/Planning/Blueprints/%3CSIDEBOARD%3E/osd:_tiering:_object_redirects > > Do you have a shorter summary than the code of how these stub and > unstub operations relate to the object redirects? We didn't make a > great deal of use of them but the basic data structures are mostly > present in the codebase, are interpreted in at least some of the right > places, and were definitely intended to cover this kind of use case. > :) > -Greg As far as I understood the redirect feature it is about pointing to other objects inside the Ceph cluster. The stubs feature allows pointing to anything. An HTTP server in concept code. Then stubs use an IMHO simpler approach to getting objects back: It's the task of the OSD. Stubbed objects just take longer to access, due to unstubbing it first. Redirects on the other hand leave this to the client: Object redirected -> Tell client to retrieve it elsewhere. ~marcel -- Marcel Lauhoff Mail/XMPP: ml@irq0.org http://irq0.org