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From Aaron Morton <>
Subject Re: cassandra 1.2.5- virtual nodes (num_token) pros/cons?
Date Mon, 12 Aug 2013 21:09:43 GMT
> Aaron - I read about the virtual nodes at

Thanks, I did not see anything in there about making repair smoother / faster. 

Aaron Morton
Cassandra Consultant
New Zealand


On 10/08/2013, at 11:39 AM, rash aroskar <> wrote:

> Aaron - I read about the virtual nodes at
> On Tue, Aug 6, 2013 at 4:49 AM, Richard Low <> wrote:
> On 6 August 2013 08:40, Aaron Morton <> wrote:
>> The reason for me looking at virtual nodes is because of terrible experiences we
had with 0.8 repairs and as per documentation (an logically) the virtual nodes seems like
it will help repairs being smoother. Is this true?
> I've not thought too much about how they help repair run smoother, what was the documentation
you read ? 
> There might be a slight improvement but I haven't observed any.  The difference might
be that, because every node shares replicas with every other (with high probability), a single
repair operation does the same work on the node it was called on, but the rest is spread out
over the cluster, rather than just the RF nodes either side of the repairing node.  This means
the post-repair compaction work will take less time and the length of time a node is loaded
for during repair is less.
> However, the other benefits of vnodes are likely to be much more useful.
> Richard.

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