Anurag, The Cassandra ring spans datacenters, so you can't use token 0 on both nodes. Cassandra’s ring is from 0 to 2**127 in size.
Try assigning one node the token of 0 and the second node 8.50705917 × 10^37 (input this as a single long number). To add a new keyspace in 0.8, run this from the CLI: create keyspace KEYSPACENAME with placement_strategy = org.apache.Cassandra.locator.NetworkTopologyStrategy' and strategy_options = [{replication_factor:2}]; If using 0.7, run "help create keyspace;" from the CLI and it'll show you the correct syntax. More info on tokens: http://journal.paul.querna.org/articles/2010/09/24/cassandra-token-selection/ <http://journal.paul.querna.org/articles/2010/09/24/cassandra-token-selection/> http://wiki.apache.org/cassandra/Operations#Token_selection On Wed, May 11, 2011 at 4:58 PM, Anurag Gujral <anurag.guj...@gmail.com>wrote: > Hi All, > I am testing network topology strategy in cassandra I am using > two nodes , one node each in different data center. > Since the nodes are in different dc I assigned token 0 to both the nodes. > I added both the nodes as seeds in the cassandra.yaml and I am using > properyfilesnitch as endpoint snitch where I have specified the colo > details. > > I started first node then I when I restarted second node I got an error > that token "0" is already being used.Why am I getting this error. > > Second Question: I already have cassandra running in two different data > centers I want to add a new keyspace which uses networkTopology strategy > in the light of above errors how can I accomplish this. > > > Thanks > Anurag >