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.aros...@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 > -- Atenciosamente, Sávio S. Teles de Oliveira voice: +55 62 9136 6996 http://br.linkedin.com/in/savioteles Mestrando em Ciências da Computação - UFG Arquiteto de Software Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
