AJ, sorry I seemed to miss the original email on this thread. As Aaron said, when computing tokens for multiple data centers, you should compute them independently for each data center - as if it were its own Cassandra cluster.
You can have "overlapping" token ranges between multiple data centers, but no two nodes can have the same token, so for subsequent data centers I just increment the tokens. For two data centers with two nodes each using RandomPartitioner calculate the tokens for the first DC normally, but int he second data center, increment the tokens by one. In DC 1 node 1 = 0 node 2 = 85070591730234615865843651857942052864 In DC 2 node 1 = 1 node 2 = 85070591730234615865843651857942052865 For RowMutations this will give each data center a local set of nodes that it can write to for complete coverage of the entire token space. If you are using NetworkTopologyStrategy for replication, it will give an offset mirror replication between the two data centers so that your replicas will not get pinned to a node in the remote DC. There are other ways to select the tokens, but the increment method is the simplest to manage and continue to grow with. Hope that helps. -Eric
