From mboxrd@z Thu Jan 1 00:00:00 1970 From: A Large Angry SCM Subject: Re: Google Code: Support for Mercurial and Analysis of Git and Mercurial Date: Sun, 26 Apr 2009 13:33:36 -0400 Message-ID: <49F49AF0.1020301@gmail.com> References: <200904260703.31243.chriscool@tuxfamily.org> <49F475B8.20903@gmail.com> Reply-To: gitzilla@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Jakub Narebski , Christian Couder , git@vger.kernel.org To: Johannes Schindelin X-From: git-owner@vger.kernel.org Mon Apr 27 11:41:58 2009 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1Ly8G4-0000YZ-H0 for gcvg-git-2@gmane.org; Sun, 26 Apr 2009 19:35:17 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754235AbZDZRdl (ORCPT ); Sun, 26 Apr 2009 13:33:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754150AbZDZRdk (ORCPT ); Sun, 26 Apr 2009 13:33:40 -0400 Received: from yw-out-2324.google.com ([74.125.46.28]:41961 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753610AbZDZRdk (ORCPT ); Sun, 26 Apr 2009 13:33:40 -0400 Received: by yw-out-2324.google.com with SMTP id 5so1161029ywb.1 for ; Sun, 26 Apr 2009 10:33:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id :disposition-notification-to:date:from:reply-to:user-agent :mime-version:to:cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=EEKz65Hon+ZwmeSJqSUkuJDKheXiQZE1aTOg3z3yd9o=; b=m/ip86Ajx8Yb9ITvNWodeQs6PMVFo8HFnK4ZXzm8nioWBMVS9ZIxxuyZWtO8zZx4mh ntPH99hi/j7DwuTSNKOFatSvL+3UtzQ9+QlncBKIsoty0Yuy04xMRsLF2RCUOfUohV24 DItLpUk4d+O/IhKHRNh28egxH2d7CaPG1wDqU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:disposition-notification-to:date:from:reply-to :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; b=XQUuDxR8gxJ200RNnTBZgIPgUQyKND4G4VXvt2zwokDUGXfn/ohpe4QUQonR1iFj+6 9nV4fO2AcsMrzKdY0RB7f7N8i3fzsG5QakyMoRopJT3dAfN9kD+sZ2t74vNxvZOUq0v2 FHb03U6Yd0cfvSCrH2GY0/i3eqZ3cq7lXtOhs= Received: by 10.100.33.15 with SMTP id g15mr7091953ang.103.1240767218912; Sun, 26 Apr 2009 10:33:38 -0700 (PDT) Received: from ?10.0.0.6? (c-66-177-19-100.hsd1.fl.comcast.net [66.177.19.100]) by mx.google.com with ESMTPS id d12sm7151455and.3.2009.04.26.10.33.37 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 26 Apr 2009 10:33:38 -0700 (PDT) User-Agent: Thunderbird 1.5.0.10 (X11/20060911) In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Johannes Schindelin wrote: > Hi, > > On Sun, 26 Apr 2009, A Large Angry SCM wrote: > >> Another important criteria was which, both or neither of Git and Hg >> would actually work and perform well on top of Google Code's underling >> storage system and except to mention they would be using Bigtable, the >> report did not discuss this. Git on top of Bigtable will not perform >> well. > > Actually, did we not arrive at the conclusion that it could perform well > at least with the filesystem layer on top of big table, but even better if > the big tables stored certain chunks (not really all that different from > the chunks needed for mirror-sync!)? > > Back when I discussed this with a Googler, it was all too obvious that > they are not interested (and in the meantime I understand why, see my > other mail). > I don't remember the mirror-sync discussion. But I do remember that when the discussion turned to implementing a filesystem on top of Bigtable that would not cause performance problems for Git, my response was that you'd still be much better off going to GFS directly instead of faking a filesystem on top of Bigtable without all of the Bigtable limitations. Bigtable _is_ appealing to implement the Git object store on. It's too bad the latency in Bigtable would make it horribly slow.