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From Theo Hultberg <>
Subject Re: Why so many vnodes?
Date Mon, 10 Jun 2013 17:55:46 GMT
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.


On Mon, Jun 10, 2013 at 4:54 PM, Milind Parikh <>wrote:

> There are n vnodes regardless of the size of the physical cluster.
> Regards
> Milind
> On Jun 10, 2013 7:48 AM, "Theo Hultberg" <> 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

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