jMeter causing a performance degradation..

[chilak <sc...@gmail.com>]

A GlassFish Performance Testing blog reports a problem with jMeter 'causing'
a performance degradation..

excerpt:
...
It turns on that the jmeter script was using an Aggregate Report. That
report, in addition to updating the throughput for each request, also
updates various statistics, including the 90% response time. It does this in
real-time, which may seem like a good idea: but the problem is that
calculating the 90% response time is an O(n) operation: the more requests
jmeter made, the longer it took to calculate the 90% time
--

Scott Oaks' blog:
http://weblogs.java.net/blog/sdo/archive/2008/01/dont_necessaril.html

Has this been addressed?

thanks


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Re: jMeter causing a performance degradation..

[sebb <se...@gmail.com>]

On 01/04/2009, chilak <sc...@gmail.com> wrote:
>
>  A GlassFish Performance Testing blog reports a problem with jMeter 'causing'
>  a performance degradation..
>
>  excerpt:
>  ...
>  It turns on that the jmeter script was using an Aggregate Report. That
>  report, in addition to updating the throughput for each request, also
>  updates various statistics, including the 90% response time. It does this in
>  real-time, which may seem like a good idea: but the problem is that
>  calculating the 90% response time is an O(n) operation: the more requests
>  jmeter made, the longer it took to calculate the 90% time
>  --
>
>  Scott Oaks' blog:
>  http://weblogs.java.net/blog/sdo/archive/2008/01/dont_necessaril.html
>
>  Has this been addressed?

I don't think it's possible to improve the algorithm, but patches welcome.

The documentation for Listeners does point out that some are more
expensive than others, and of course one can record the data in a file
and reload it after the test.

Not sure there's anything else that can be done.

>  thanks
>
>
>
>  --
>  View this message in context: http://www.nabble.com/jMeter-causing-a-performance-degradation..-tp22834994p22834994.html
>  Sent from the JMeter - User mailing list archive at Nabble.com.
>
>
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>

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