From mboxrd@z Thu Jan 1 00:00:00 1970 From: Farrukh Najmi Subject: Re: Any plans to support JTA and XA in jgit? Date: Fri, 14 Nov 2008 09:45:51 -0500 Message-ID: <491D8F1F.7090803@wellfleetsoftware.com> References: <200811132059.16616.robin.rosenberg.lists@dewire.com> <491C8DBE.9080105@wellfleetsoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org To: Kyle Moffett X-From: git-owner@vger.kernel.org Fri Nov 14 15:47:09 2008 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 1L0zwy-0006Zl-EH for gcvg-git-2@gmane.org; Fri, 14 Nov 2008 15:47:08 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751190AbYKNOpx (ORCPT ); Fri, 14 Nov 2008 09:45:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751159AbYKNOpx (ORCPT ); Fri, 14 Nov 2008 09:45:53 -0500 Received: from vms046pub.verizon.net ([206.46.252.46]:38332 "EHLO vms046pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750727AbYKNOpw (ORCPT ); Fri, 14 Nov 2008 09:45:52 -0500 Received: from [192.168.1.101] ([71.184.206.167]) by vms046.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0KAB00D3HVOF3VZ1@vms046.mailsrvcs.net> for git@vger.kernel.org; Fri, 14 Nov 2008 08:45:52 -0600 (CST) In-reply-to: User-Agent: Thunderbird 2.0.0.17 (X11/20080925) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Kyle Moffett wrote: > On Thu, Nov 13, 2008 at 3:27 PM, Farrukh Najmi > wrote: > >> The problem I am trying to solve is this. In my service I need to store >> metadata in a relational db and content in git such that both either commit >> or not in a single transaction. If one commits and the other does not that >> is a serious integrity issue. Seems to me, two phase commit would be the >> right solution for that in the long run. This what JDBC + JMS topologies do. >> > > That's really easy! First tweak jgit so that *instead* of using > .git/refs, it uses your database to store references and exports them > on a routine basis to .git/refs for debugging purposes. Wow! This does sound simple in theory. Of course I have much to learn about jgit code base first. Any pointers on what parts of the code are involved that I should start looking at? I would hate to keep a fork of gjit around. Would this work be of interest to the project if it could be done in a way that a few properties control whether to use database or not? Thanks Kyle! > Then, for > each database update: > > (1) Start transaction > (2) Commit the change to GIT (adds ref update to the transaction) > (3) Make other metadata updates > (4) Commit transaction > > Then set up periodic garbage collection and you're done! If the > transaction is aborted, there will simply be a bunch of random loose > objects in the git repository, which will be cleaned up the next time > you garbage collect. The ref update will be atomic and conditional > with the rest of the transaction, and in git the *only* part that > really matters for atomicity is the ref. > > Cheers, > Kyle Moffett > > -- Regards, Farrukh Najmi Web: http://www.wellfleetsoftware.com