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.
