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From Hontvári József Levente <hontv...@flyordie.com>
Subject Re: Cassandra Evaluation/ Benchmarking: Throughput not scaling as expected neither latency showing good numbers
Date Wed, 18 Jul 2012 14:17:15 GMT
On 2012.07.18. 7:13, Code Box wrote:
> The cassandra stress tool gives me values around 2.5 milli seconds for 
> writing. The problem with the Cassandra Stress Tool is that it just 
> gives the average latency numbers and the average latency numbers that 
> i am getting are comparable in some cases. It is the 95 percentile and 
> 99 percentile numbers are the ones that are bad. So it means that the 
> 95% of requests are really bad and the rest 5% are really good that 
> makes the average go down.


No, the opposite is true. 95% of the requests are fast, and 5% is slow. 
Or in case of the 99 percentile, 99% is fast, 1% is slow. Except if you 
order your samples in the opposite direction, not in the usual.

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