From: Farrukh Najmi Date: Fri, 14 Nov 2008 14:45:51 GMT Subject: Re: Any plans to support JTA and XA in jgit? Message-ID: <491D8F1F.7090803@wellfleetsoftware.com> In-Reply-To: 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