It is very useful to upgrade the apps perfomance.
For example, if you have a machine with X capacity, you can put the num_token=256. If you add a machine in your cluster with (X*2) capacity you can put the num_token=512.
So, this new machine will receive twice the load automatically.
Moreover, you can minimize how long a machine replacement is going to take and will minimize the time to repair a disk failure.

Read the docs to more informations: http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2

Cheers!



2013/7/25 rash aroskar <rashmi.aroskar@gmail.com>
Hi,
I am upgrading my cassandra cluster from 0.8 to 1.2.5. 
In cassandra 1.2.5 the 'num_token' attribute confuses me. 
I understand that it distributes multiple tokens per node but I am not clear how that is helpful for performance or load balancing. Can anyone elaborate? has anyone used this feature  and knows its advantages/disadvantages?

Thanks,
Rashmi



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Mestrando em Ciências da Computação - UFG
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