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From AJ ...@dude.podzone.net>
Subject Re: Docs: Token Selection
Date Wed, 15 Jun 2011 19:28:15 GMT
On 6/15/2011 12:14 PM, Vijay wrote:
> Correction....
>
> "The problem in the above approach is you have 2 nodes between 12 to 4 
> in DC1 but from 4 to 12  you just have 1"
>
> should be
>
> "The problem in the above approach is you have 1 node between 0-4 
> (25%) and and one node covering the rest which is 4-16, 0-0 (75%)"
>
> Regards,
> </VJ>
>

Ok, I think you are saying that the computed token range intervals are 
incorrect and that they would be:

DC1
*node 1 = 0      Range: (4, 16], (0, 0]
node 2 = 4      Range: (0, 4]

DC2
*node 3 = 8      Range: (12, 16], (0, 8]
node 4 = 12   Range: (8, 12]

If so, then yes, this is what I am seeking to confirm since I haven't 
found any documentation stating this directly and that reference that I 
gave only implies this; that is, that the token ranges are calculated 
per data center rather than per cluster.  I just need someone to confirm 
that 100% because it doesn't sound right to me based on everything else 
I've read.

SO, the question is:  Does Cass calculate the consecutive node token 
ranges A.) per cluster, or B.) for the whole data center?

 From all I understand, the answer is B.  But, that documentation 
(reprinted below) implies A... or something that doesn't make sense to 
me because of the token placement in the example:

"With NetworkTopologyStrategy, you should calculate the tokens the nodes 
in each DC independantly...

DC1
node 1 = 0
node 2 = 85070591730234615865843651857942052864

DC2
node 3 = 1
node 4 = 85070591730234615865843651857942052865"


However, I do see why this would be helpful, but first I'm just asking if this token assignment
is absolutely mandatory
or if it's just a technique to achieve some end.




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