Eric, Jonathan is suggesting the approach Jeremiah was using. Calculate the tokens the nodes in each DC independantly, and then add 1 to the tokens if there are two nodes with the same tokens.
In your case with 2 DC's with 2 nodes each. In DC 1 node 1 = 0 node 2 = 85070591730234615865843651857942052864 In DC 2 node 1 = 1 node 2 = 85070591730234615865843651857942052865 This will evenly distribute the keys in each DC, which is what the NetworkTopologyStrategy is trying to do. You can make this change using nodetool move. Hope that helps. ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 4 May 2011, at 08:20, Eric tamme wrote: > On Tue, May 3, 2011 at 4:08 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >> On Tue, May 3, 2011 at 2:46 PM, aaron morton <aa...@thelastpickle.com> wrote: >>> Jonathan, >>> I think you are saying each DC should have it's own (logical) token >>> ring. >> >> Right. (Only with NTS, although you'd usually end up with a similar >> effect if you alternate DC locations for nodes in a ONTS cluster.) >> >>> But currently two endpoints cannot have the same token regardless of >>> the DC they are in. >> >> Also right. >> >>> Or should people just bump the tokens in extra DC's to avoid the collision? >> >> Yes. >> > > > I am sorry, but I do not understand fully. I would appreciate it if > some one could explain with more verbosity for me. > > I do not understand why data insertion is even, but replication is not. > > I do not understand how to solve the problem. What does "bumping" > tokens entail - Is that going to change my insertion distribution? I > had no idea you can create different logical keyspaces ... and I am > not sure what that exactly means... or that I even want to do it. Is > there a clear solution to "fixing" the problem I laid out, and getting > replication data evenly distributed between racks in each DC? > > Sorry again for needing more verbosity - I am learning as I go with > this stuff. I appreciate everyones help. > > -Eric