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From David Strauss <da...@fourkitchens.com>
Subject Re: Memcached protocol?
Date Mon, 05 Apr 2010 08:02:59 GMT
On 2010-04-05 07:47, Paul Prescod wrote:
> On Mon, Apr 5, 2010 at 12:01 AM, David Strauss <david@fourkitchens.com> wrote:
>> On 2010-04-05 03:42, Paul Prescod wrote:
>> ...
>>
>> There is a difference between Cassandra allowing inc/dec on values and
>> actually *knowing* the resultant value at the time of the write. It's
>> likely that inc/dec support will still feature blind writes if at all
>> possible. The memcached protocol returns a resultant value from inc/dec.
> 
> Right. That's why I said that the proxy layer would need to read the
> result with an appropriate consistency level before returning to the
> memcached client application. The client application would need to
> declare its consistency preference using a configuration file.

But your "write then read" model lacks the atomicity of the memcached
API. It's possible for two clients to read the same value.

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


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