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From Vijay <vijay2...@gmail.com>
Subject Re: Docs: Token Selection
Date Wed, 15 Jun 2011 00:10:42 GMT
Yes... Thats right...  If you are trying to say the below...

DC1
Node1 Owns 50%

(Ranges 8..4 -> 8..5 & 8..5 -> 0)

Node2 Owns 50%

(Ranges 0 -> 1 & 1 -> 8..4)


DC2
Node1 Owns 50%

(Ranges 8..5 -> 0 & 0 -> 1)

Node2 Owns 50%

(Ranges 1 -> 8..4 & 8..4 -> 8..5)


Regards,
</VJ>



On Tue, Jun 14, 2011 at 3:47 PM, AJ <aj@dude.podzone.net> wrote:

> This http://wiki.apache.org/cassandra/Operations#Token_selection  says:
>
> "With NetworkTopologyStrategy, you should calculate the tokens the nodes in
> each DC independantly."
>
> and gives the example:
>
> DC1
> node 1 = 0
> node 2 = 85070591730234615865843651857942052864
>
> DC2
> node 3 = 1
> node 4 = 85070591730234615865843651857942052865
>
>
> So, according to the above, the token ranges would be (abbreviated nums):
>
> DC1
> node 1 = 0      Range: (8..4, 16], (0, 0]
> node 2 = 8..4   Range: (0, 8..4]
>
> DC2
> node 3 = 1      Range: (8..5, 16], (0, 1]
> node 4 = 8..5   Range: (1, 8..5]
>
>
> If the above is correct, then I would be surprised as this paragraph is the
> only place were one would discover this and may be easy to miss... unless
> there's a doc buried somewhere in plain view that I missed.
>
> So, have I interpreted this paragraph correctly?  Was this design to help
> keep data somewhat localized if that was important, such as a geographically
> dispersed DC?
>
> Thanks!
>

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