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From A J <s5a...@gmail.com>
Subject Re: Force a node to form part of quorum
Date Thu, 16 Jun 2011 21:25:08 GMT
It would be great if Cassandra puts this on their roadmap. There is
lot of durability benefits by incorporating dc awareness into the
write consistency equation.

MongoDB has this feature in their upcoming release:
http://www.mongodb.org/display/DOCS/Data+Center+Awareness#DataCenterAwareness-Tagging%28version1.9.1%29



On Thu, Jun 16, 2011 at 6:57 AM, aaron morton <aaron@thelastpickle.com> wrote:
> Short answer:  No.
> Medium answer: No all nodes are equal. It could create a single point of
> failure if a QUOURM could not be formed without a specific node.
> Writes are sent to every replica. Reads with Read Repair enabled are also
> sent to every replica. For reads the "closest" UP node as determined by the
> snitch and possibly re-ordered by the Dynamic Snitch  is asked to return the
> actual data. This replica must respond for the request to complete.
> If it's a question about maximising cache hits
> see https://github.com/apache/cassandra/blob/cassandra-0.8.0/conf/cassandra.yaml#L308
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> @aaronmorton
> http://www.thelastpickle.com
> On 16 Jun 2011, at 05:58, A J wrote:
>
> Is there a way to favor a node to always participate (or never
> participate) towards fulfillment of read consistency as well as write
> consistency ?
>
> Thanks
> AJ
>
>

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