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From Brandon Williams <dri...@gmail.com>
Subject Re: performance tuning - where does the slowness come from?
Date Wed, 05 May 2010 23:46:59 GMT
On Wed, May 5, 2010 at 6:36 PM, Mark Jones <MJones@imagehawk.com> wrote:

>  Have you actually managed to get 10K reads/second, or are you just
> estimating that you can?  I’ve run into similar issues, but I never got
> reads to scale when searching for unique keys even using 40 threads, I did
> discover that using 80+ threads, I can actually reduce performance.  I’ve
> never gotten more than 200-300 reads/second (steady state) off a 4 cluster
> node.  I can get roughly 8K writes/second to the same cluster (although I
> haven’t tested both simultaneously with results worth talking about).
>

200-300/s is pretty low, especially if you can get 8k writes/s.  I would
estimate that you should be getting at least a couple thousand reads/s.
 Here is what I've gotten from a quad core machine with two disks:

http://racklabs.com/~bwilliam/cassandra/04vs05vs06.png

How much data are you testing with?

-Brandon

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