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From David Strauss <da...@fourkitchens.com>
Subject Re: serialized vector clock as global counter?
Date Mon, 15 Mar 2010 00:47:06 GMT
On 2010-03-14 16:46, Toby DiPasquale wrote:
> My question would be: assuming we're using both quorum reads and
> writes, is it possible that clients A and B could race in the
> following manner:
> 
> * A updates its counter
> * B updates its counter
> * A reads the keys to get sum X
> * B reads the keys to get the same sum X
> 
> ...thus violating the ever-increasing constraint?

Yes. You'd need a cluster-wide lock to solve that problem, but then you
may as well use that same cluster-wide locking mechanism to maintain the
count.

You'll get more interesting responses from this list if you share the
original problem you're trying to solve instead of asking us how to
implement a component of your chosen solution.

-- 
David Strauss
   | david@fourkitchens.com
Four Kitchens
   | http://fourkitchens.com
   | +1 512 454 6659 [office]
   | +1 512 870 8453 [direct]


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