[tahoe-dev] split brain? how handled in tahoe -- docs?

Tony Arcieri tony.arcieri at gmail.com
Wed Aug 8 08:42:21 UTC 2012


Awesome! Is the merge algorithm documented anywhere? Is it a patch-style
algorithm, or more advanced?

On Wed, Aug 8, 2012 at 1:40 AM, Zooko Wilcox-O'Hearn <zooko at zooko.com>wrote:

> On Wed, Aug 8, 2012 at 2:31 AM, Zooko Wilcox-O'Hearn <zooko at zooko.com>
> wrote:
> > On Mon, Aug 6, 2012 at 1:38 PM, Tony Arcieri <tony.arcieri at gmail.com>
> wrote:
> >
> >> From what I've read of how Tahoe handles conflicts, it employs a
> monotonic
> >> version number and timestamps. So it sounds like in the event of a
> conflict,
> >> Tahoe employs a last writer wins strategy?
>
> Oh, except actually I momentarily forgot how this works. One of your
> guesses is actually wrong. What happens if you attempt to write to a
> mutable file or directory at the same time that someone else does is
> one or both of you gets an Uncoordinated Write Error:
>
>
> https://tahoe-lafs.org/trac/tahoe-lafs/browser/git/docs/write_coordination.rst?rev=08ea3dc512be2e331aa486f818ba9d5f2fe2c4cb
>
> It gets a little more complicated, because there is a feature (which I
> don't like and want to kill) that if the operation you are doing is
> modifying a mutable directory (such as by adding or removing links
> from that directory), and it gets an Uncoordinated Write Error, then
> it will, I think exactly one time, attempt to automatically merge your
> edit (e.g. addition of a child link) into the new version of the
> directory (i.e. the version that was written uncoordinatedly by
> someone or something else) and then reupload the resulting
> automatically merged directory.
>
> Regards,
>
> Zooko
> _______________________________________________
> tahoe-dev mailing list
> tahoe-dev at tahoe-lafs.org
> https://tahoe-lafs.org/cgi-bin/mailman/listinfo/tahoe-dev
>



-- 
Tony Arcieri
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://tahoe-lafs.org/pipermail/tahoe-dev/attachments/20120808/276d7c2a/attachment.html>


More information about the tahoe-dev mailing list