The other concensus problem

On Thu, Jan 09, 2003 at 03:07:46PM -0800, Assaf Arkin wrote:
> A lot of the comments made with regards to the HTTP GET/PUT approach so far
> seem to mirror these algorithms,

That's no coincidence! 8-)

> though for the most part I would say that
> the discussion has ignored some of the safety mechanism that is required for
> reliability, such as round identifiers and failure detection.

That's true, we have ignored those in the discussion.  But consider;

http://www.w3.org/1999/04/Editing/

which is a solution to the "lost update" problem, i.e. where subsequent
rounds modify the actions of prior rounds.  Etags aren't round
identifiers, but are state identifiers which can be used similarly.

> Just pointing out that this discussion could be elevated if we could look at
> what was already researched/done rather than trying to re-invent the wheel.

Excellent idea!  I think I'm doing just that, only not talking about it
at that detailed a level.

> Personally, I have actually implemented this stuff and I think it's superior
> to traditional coordination protocols in its ability to address failure.

What do you mean by "traditional coordination protocols"?  Most of the
coordination protocols I know about are quite aware of these issues.

> There's a whole class of use cases where you would want to use these
> algorithms, and definitely a good learning opportunity for the WS community.

Agreed!

MB
-- 
Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca
Web architecture consulting, technical reports, evaluation & analysis