incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Richard Low <rich...@wentnet.com>
Subject Re: cassandra 1.2.5- virtual nodes (num_token) pros/cons?
Date Tue, 13 Aug 2013 11:13:54 GMT
On 13 August 2013 10:15, Alain RODRIGUEZ <arodrime@gmail.com> wrote:

Streaming from all the physical nodes in the cluster should make repair
> faster, for the same reason it makes bootstrap faster. Shouldn't it ?
>

Virtual nodes doesn't speed up either very much.  Repair and bootstrap will
be limited by the node doing repair or bootstrap, since it has to do the
same amount of work whatever num_tokens is.  It places a more even load
across the rest of the cluster though, since it will repair with or
bootstrap from all nodes in the cluster.  So the overall time will in most
cases be about the same.

The real speedup from vnodes comes when running removenode, when the
streaming happens in parallel across all nodes.

Richard.

Mime
View raw message