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From "Sibbald, Charles" <>
Subject Re: Replication to second data center with different number of nodes
Date Fri, 27 Mar 2015 10:58:56 GMT
I would recommend you utilise Cassandra’s Vnodes config and let it manage this itself.

This means it will create these and a mange them all on its own and allows quick and easy
scaling and boot strapping.

From: Björn Hachmann <<>>
Reply-To: "<>" <<>>
Date: Friday, 27 March 2015 10:40
To: user <<>>
Subject: Replication to second data center with different number of nodes


we currently plan to add a second data center to our Cassandra-Cluster. I have read about
this procedure in the documentation (eg.,
but at least one question remains:

Do I have to provide appropriate values for num_tokens dependent on the number of nodes per
data center, or is this handled somehow by the NetworkTopologyStrategy?

Example: We currently have 12 nodes each covering 256 tokens. Our second datacenter will have
three nodes only. Do I have to set num_tokens to 1024 (12*256/3) for the nodes in that DC?

Thank you very much for your valuable input!

Kind regards
Björn Hachmann
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