Details are very welcome as I'm still not sure whether I fully understand the problem :)
Thread pooling does sound nice and it might enable a feature I'd like: On-demand creation of threads. Say you're looping 10 threads, system is under no load. Currently: if you want 10 more users you need to stop the test, add 10 users and start it again. It would be nice if it where possible to simply say '+10', followed by some monitoring and then another '+10' (30 threads running total) etc. (10 is an example number, +/- n users would be the goal) Mostly for the 'getting a feel for the system' part of the test, the initial setup of it all. Regards, Daniel On Fri, Jun 15, 2012 at 7:24 AM, Kirk Pepperdine <kirk.pepperd...@gmail.com> wrote: > Hi, > > I'm very happy to add details if need be. > > Regards, > Kirk > > On 2012-06-15, at 12:13 AM, Philippe Mouawad wrote: > >> Bugzilla created: >> >> - https://issues.apache.org/bugzilla/show_bug.cgi?id=53418 >> >> >> Regards >> >> Philippe M. >> >> On Thu, Jun 14, 2012 at 10:30 PM, Philippe Mouawad < >> philippe.moua...@gmail.com> wrote: >> >>> Hi M. Pepperdine, >>> >>> On Wed, Jun 13, 2012 at 7:05 AM, Kirk Pepperdine < >>> kirk.pepperd...@gmail.com> wrote: >>> >>>> Hi Sebb, >>>> >>>> We've had this conversation before and I did some preliminary work to >>>> setup a different type of thread group but the couplings between the >>>> existing thread group and the model meant that an extensive refactoring >>>> would be involved. Since that involves a *lot* more than just a simple >>>> plugin... >>>> >>>> So, the current implementation supports a closed system model meaning, >>>> rate of entry into the system equals rate of exit from the system.This is >>>> exactly what you want if you're load testing a call centre where the number >>>> of servers (operators) is fixed and gate entry into the system. However, >>>> I'm often simulating open systems which means I do not want rate of entry >>>> into the system to be controlled by the performance of the system (rate of >>>> exit). >>> >>> What makes you think JMeter does this ? >>> >>> >>>> More over, those that attend my performance tuning seminars come to >>>> understand why this is an important aspect of getting your test environment >>>> right and test harness correctly setup as it can adversely affect the >>>> quality of your test which can and often does, change the results of the >>>> test. >>>> >>> >>>> As an example, today I will show a group how to tune an application by a >>>> partner company. That application has a number of "performance problems" >>>> backed into it. If I use the traditional means of using JMeter I will find >>>> a different set of performance issues than if I load with a pattern that is >>>> similar that found in production. >>> >>> Can you clarify this point ? a figure might be better than a long text >>> >>> >>>> In other words, with this particular application, JMeter exposes >>>> "problems" that are artifacts of how it wants to inject load on a system. >>> >>> Not clear for me. >>> >>> I can fix all of these problems >>> >>> What are these problems ? and how do you fix these ? >>> >>> >>>> and eventually I'll get to a point where I'll fix everything that needs >>>> to be fixed. That said, if I can coerce JMeter to load as an open system >>>> I'll get to the problems without having to fix the artifacts (the things >>>> that really don't need fixing). >>> >>> Still not clear >>> >>>> To coerce JMeter into being an open system requires one to use a large >>>> number of very short lived threads. So I may only have 400-500 active >>>> threads at any point in time but in order to achieve that load over a 1 or >>>> two hour test I may have to specify 10s of thousands of threads. Since all >>>> of the threads are created up front, this simply doesn't work. >>>> >>>> You might ask why not just specify 400-500 threads and loop over them? in >>>> theory you'd think it would work but as you tune the system and the >>>> performance characteristics change. Going back to the baked application, >>>> before I start tuning, the active user count is several thousand. In other >>>> words, the tuned system is better able to clear users out and that changes >>>> the performance profile in a way that hard to emulate with the current >>>> looping behaviour. Using a setting of looping 400 or so threads isn't >>>> adequate for the initial load tests as the test harness will become thread >>>> starved and that releases pressure on the server which in turn changes the >>>> performance profile. >>>> >>> >>> >>>> With all due respect to the wonderful work that everyone on the project >>>> has done, it is my opinion that the one user == one thread is a design >>>> mistake that has a huge impact on both the usability of the tool >>>> >>> Examples ? >>> >>>> and the quality of the results >>> >>> I disagree with this assertion . We have been using JMeter for load >>> testing all kind of applications Intranets / Large ECommerce Systems / >>> Backoffice systems / , and quality of results is good provided you >>> configure it properly. >>> Particularly when using Remote Testing. Lot of users in this mailing list >>> use it and are satisfied (I think). >>> >>> >>>> one can achieve when using it. IMHO, moving to an thread pool/event heap >>>> based model would be an enormous improvement over the current >>>> implementation. >>>> >>>> Agree it would be better. We will work on it. >>> >>>> Regards, >>>> Kirk >>>> >>>> On 2012-06-13, at 1:02 AM, sebb wrote: >>>> >>>>> On 12 June 2012 22:57, Kirk Pepperdine <kirk.pepperd...@gmail.com> >>>> wrote: >>>>>> >>>>>> On 2012-06-13, at 12:54 AM, sebb wrote: >>>>>> >>>>>>> On 12 June 2012 22:06, Kirk Pepperdine <kirk.pepperd...@gmail.com> >>>> wrote: >>>>>>>> Hi, >>>>>>>> >>>>>>>> I figured thread pooling would be revolutionary so I wasn't >>>> suggesting that. I would be very useful just delay the creation of a thread >>>> until it was asked for. >>>>>>> >>>>>>> Not sure I understand how it would help to delay the thread creation, >>>>>>> except perhaps for the case where the first threads have finished >>>>>>> processing by the time the last threads start running samples. >>>>>> >>>>>> Bingo!!! ;-) >>>>> >>>>> So what percentage of use cases need to follow this model? >>>>> >>>>> Most of the JMeter testing I have done was long running tests where >>>>> all threads were active for most of the run. >>>>> >>>>>> Kirk >>>>>> >>>>>> >>>>>> --------------------------------------------------------------------- >>>>>> To unsubscribe, e-mail: user-unsubscr...@jmeter.apache.org >>>>>> For additional commands, e-mail: user-h...@jmeter.apache.org >>>>>> >>>>> >>>>> --------------------------------------------------------------------- >>>>> To unsubscribe, e-mail: user-unsubscr...@jmeter.apache.org >>>>> For additional commands, e-mail: user-h...@jmeter.apache.org >>>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: user-unsubscr...@jmeter.apache.org >>>> For additional commands, e-mail: user-h...@jmeter.apache.org >>>> >>>> >>> >>> >>> -- >>> Cordialement. >>> Philippe Mouawad. >>> >>> >>> >>> >> >> >> -- >> Cordialement. >> Philippe Mouawad. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@jmeter.apache.org > For additional commands, e-mail: user-h...@jmeter.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@jmeter.apache.org For additional commands, e-mail: user-h...@jmeter.apache.org
