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

[Tony Arcieri]

On Mon, Aug 6, 2012 at 12:30 PM, Zooko Wilcox-O'Hearn <zooko at zooko.com>wrote:

> “At Virginia Tech Linux and Unix Users Group, we have a working
> Tahoe-LAFS deployment of about 9-14 nodes. It's incredibly reliable.
> It's based at Virginia Tech, with the introducer on a
> university-hosted servers, plus a few nodes in the dorms. One day, VT
> disappeared from the net. They had a problem with one of their uplinks
> and all their edge routers stopped routing. The introducer and about
> half the nodes on the grid were down for maybe an hour. At no point
> was any data stored on the grid inaccessible to any of the nodes,
> because all the ones outside could talk to the ones outside, and the
> ones inside could talk to the ones inside.”—Marcus Wanner
>
> How can both that story and also the things that have already been
> posted on this thread both be true?
>
> I think I'll just leave it at that for now.


As far as CAP theorem goes, it sounds like Tahoe falls into the AP space,
that is: network partitions do not (necessarily) result in a loss of
availability of service, however the two partitions may become inconsistent
during the event of a network partition.

>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?

-- 
Tony Arcieri
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