On Wed, Jul 15, 2015 at 9:28 AM, Benyi Wang <bewang.t...@gmail.com> wrote:
> I have a small cluster with 3 nodes and installed Cassandra 2.1.2 from > DataStax YUM repository. I knew 2.1.2 is not recommended for production. > I'm wondering what is the root cause of the worse performance for vnode: > > - num_token is too high for 3-node cluster? > > Wish I had a blog post to link to, but... briefly.. If you have RF=3 and under probably about 9 nodes, you probably "just lose" from having vnodes. This is because the overhead of dealing with so many ranges is not sufficiently counterbalanced by the advantages of for example significantly faster bootstrap. Vnode performance has been increasing all the time, because the other advantages are significant and so people are motivated to improve it. If you're interested in observing the significance of number of vnodes, just recreate your cluster with half, then half again tokens per node, testing each time? =Rob
