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From Kirk Pepperdine <kirk.pepperd...@gmail.com>
Subject Re: Rampup period for all iterations
Date Fri, 08 Aug 2014 05:22:34 GMT
Hi,

It actually gets worse than that. The looping behavior means that tx will be throttled by
your servers ability to process requests. The throughput shaping timer is good for slowing
things down to a particular tx rate but it cannot correct for back pressure from the server.
The only way to do that is have each tx start independently from all other requests. Unfortunately
*even* that will not give you the desired tx rate.

See http://www.infoq.com/presentations/latency-pitfalls for more details

Regards,
Kirk

On Aug 8, 2014, at 5:50 AM, Jeff Ohrstrom <johrstrom@hotmail.com> wrote:

> You can use a throughput shaping timer from the plugin package, but that
> relies on requests per second, not necessarily concurrency.  That's
> probably the cleanest way you could do this. 
> 
> However, you have to be cautious about what you're trying to do.  How
> it's affecting the concurrent users you actually have and how many you
> are expecting. 
> 
> Take your example of 100 Threads with 100 seconds ramp up and 10 loops.
> The first thread is going to kick off and given a 1 second response time
> it will finish it's loops in 10 seconds.  That means, that at the 10th
> second you think you have 10 concurrent requests, but it's actually only
> 9 because the first thread has just finished. Your concurrent users over
> time could look more like a Gaussian graph than a sawtooth if the the
> ramp up time >> than the response time * iterations. 
> 
> On Thu, 2014-08-07 at 01:08 -0700, bobMeliev wrote:
>> Thanks for response. I think I can get the expected result by changing
>> "Thread Group" properties with formula: (Number of Threads * Loop Count) /
>> Expected delay between threads = Ramp-up period. But is it possible to
>> achieve the same result without modifying thread group properties, i.e. to
>> force all iterations to use pre-defined ramp-up period? 
>> 
>> 
>> --
>> View this message in context: http://jmeter.512774.n5.nabble.com/Rampup-period-for-all-iterations-tp5720762p5720772.html
>> Sent from the JMeter - User mailing list archive at Nabble.com.
>> 
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> 
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