Yes, which means that the ranges overlap each other. 

Is this just a convention, or is it technically required when using NetworkTopologyStrategy?  Would it be acceptable to split the ranges into quarters by ignoring the data centers, such as:

DC1
node 1 = 0      Range: (12, 16], (0, 0]
node 2 = 4      Range: (0, 4]

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

If this is OK, are there any drawbacks to this? 



On 6/14/2011 6:10 PM, Vijay wrote:
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!