Option #3 since it depends on the placement strategy and not the partitioner.
-Bryan On Mon, May 20, 2013 at 6:24 AM, Pinak Pani < nishant.has.a.quest...@gmail.com> wrote: > I just wanted to verify the fact that if I happen to setup a multi > data-center Cassandra setup, will each data center have the complete > data-set with it? > > Say, I have two data-center each with two nodes, and a partitioner that > ranges from 0 to 100. Initial token assigned this way > > DC1:N1 = 00 > DC2:N1 = 25 > DC1:N2 = 50 > DC2:N2 = 75 > > where DCX is data center X, NX is node X. *Which one the following > options is true?* > > *Option #1: *DC1 and DC2, each will hold complete dataset with keys > bucketed as follows > DC1:N1 = (50, 00] => 50 keys > DC1:N2 = (00, 50] => 50 keys > ---- > Complete data set mirrored at DC1 > > DC2:N1 = (75, 25] => 50 keys > DC2:N2 = (25, 75] => 50 keys > ---- > Complete data set mirrored at DC2 > > *Option #2: *DC1 and DC2, each will hold 50% of the data with keys > bucketed as follows (much the same way in a single C setup) > DC1:N1 = (75, 00] => 25 keys > DC2:N1 = (00, 25] => 25 keys > DC1:N2 = (25, 50] => 25 keys > DC2:N2 = (50, 75] => 25 keys > ---- > data is divided into the two data centers. > > Thanks, > PP >
