incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Richard Low <>
Subject Re: 15 seconds to increment 17k keys?
Date Fri, 02 Sep 2011 14:35:03 GMT
On Thu, Sep 1, 2011 at 5:16 PM, Ian Danforth <> wrote:

> Does this scale with multiples of the replication factor or directly
> with number of nodes? Or more succinctly, to double the writes per
> second into the cluster how many more nodes would I need?

The write throughput scales with number of nodes, so double to get
double the write capacity.

Increasing the replication factor in general doesn't improve
performance (and increasing without increasing number of nodes
decreases performance).  This is because operations are performed on
all available replicas (with the exception of reads with low
consistency levels and read_repair_chance < 1.0).

Note also that there is just one read per counter increment, not a
read per replica.

Richard Low
Acunu | | @acunu

View raw message