I'm not sure I follow what you mean, or if I've misunderstood what Cassandra is telling me. Each node has 256 vnodes (or tokens, as the prefered name seems to be). When I run `nodetool status` each node is reported as having 256 vnodes, regardless of how many nodes are in the cluster. A single node cluster has 256 vnodes on the single node, a six node cluster has 256 nodes on each machine, making 1590 vnodes in total. When I run `SELECT tokens FROM system.peers` or `nodetool ring` each node lists 256 tokens.

This is different from how it works in Riak and Voldemort, if I'm not mistaken, and that is the source of my confusion.

T#


On Mon, Jun 10, 2013 at 4:54 PM, Milind Parikh <milindparikh@gmail.com> wrote:

There are n vnodes regardless of the size of the physical cluster.
Regards
Milind

On Jun 10, 2013 7:48 AM, "Theo Hultberg" <theo@iconara.net> wrote:
Hi,

The default number of vnodes is 256, is there any significance in this number? Since Cassandra's vnodes don't work like for example Riak's, where there is a fixed number of vnodes distributed evenly over the nodes, why so many? Even with a moderately sized cluster you get thousands of slices. Does this matter? If your cluster grows to over thirty machines and you start looking at ten thousand slices, would that be a problem? I guess trat traversing a list of a thousand or ten thousand slices to find where a token lives isn't a huge problem, but are there any other up or downsides to having a small or large number of vnodes per node?

I understand the benefits for splitting up the ring into pieces, for example to be able to stream data from more nodes when bootstrapping a new one, but that works even if each node only has say 32 vnodes (unless your cluster is truly huge).

yours,
Theo