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From Sameer Farooqui <cassandral...@gmail.com>
Subject Re: network topology issue
Date Thu, 12 May 2011 00:27:27 GMT
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.gujral@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
>

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