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From AJ ...@dude.podzone.net>
Subject Re: Docs: Token Selection
Date Fri, 17 Jun 2011 19:23:45 GMT
On 6/17/2011 12:32 PM, Jeremiah Jordan wrote:
> 	Run two clusters, one which has {DC1:2, DC2:1} and one which is
> {DC1:1,DC2:2}.  You can't have both in the same cluster, otherwise it
> isn't possible to tell where the data got written when you want to read
> it.  For a given key "XYZ" you must be able to compute which nodes it is
> stored on just using "XYZ", so a strategy where it is on nodes
> DC1_1,DC1_2, and DC2_1 when a node in DC1 is the coordinator, and to
> DC1_1, DC2_1 and DC2_2 when a node in DC2 is the coordinator won't work.
> Given just "XYZ" I don't know where to look for the data.
> 	But, from the way you describe what you want to happen, clients
> from DC1 aren't using data inserted by clients from DC2, so you should
> just make two different Cassandra clusters.  Once for the DC1 guys which
> is {DC1:2, DC2:1} and one for the DC2 guys which is {DC1:1,DC2:2}.
>

Interesting.  Thx.


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