Am 15.05.19 um 21:56 schrieb Philippe Mouawad: > Hi Felix, > > Thanks for your feedback. > Few questions below > > On Wed, May 15, 2019 at 9:40 PM Felix Schumacher < > [email protected]> wrote: > >> Am 15.05.19 um 17:28 schrieb Philippe Mouawad: >>> Hello, >>> >>> I'll start with my team the development of a switch to better percentiles >>> computation which will end as a PR contribution. >>> >>> To recap previous discussions: >>> >>> - We have currently 2 implementations of Percentiles : >>> - A custom one used in old listeners >>> - A new one based on commons-math >>> - CONS: >>> - It impacts maintainability as a consequence >>> - The results are different which confuses users >>> - Percentiles are not explicitly documented regarding the algorithm >>> used which also creates confusion : >>> - https://github.com/apache/jmeter/pull/295 >>> - https://github.com/apache/jmeter/pull/296 >>> - Benefits: >>> - Have one algorithm in codebase >>> - Rely on best percentile algo for our use case >>> - Rely on performing and reliable library HdrHistogram/LatencyUtils >>> - Improve CO handling >>> - PREVIOUS ACTIONS: >>> - It was agreed that switching to HdrHistogram was a good option. This >>> library is a standard now: >>> - Used in MicroMeter (used by Spring) >>> - Used in future JMC >>> >> https://mail.openjdk.java.net/pipermail/jmc-dev/2019-May/000984.html >>> - Felix started a PR: >>> - https://github.com/apache/jmeter/pull/380/files >> I updated the branch and thus the PR to be hopefully more correct than >> the old one. >> >> I still have a few doubts about the implementation. It seems to me, that >> HdrHistogram is good for collecting the stats, but not optimized for >> asking the stats a lot while the test is running. >> > Which would affect GUI mode testing only right ? I believe so. > If confirmed we would need to reduce refresh rate ? Which would probably get us a few angry mails. We could live with that, I think. > >> That is the reason, that I tried to implement the calculation of some of >> those stats myself. There is a good change, that I completely messed it up. >> > you mean " There is a good chance, that I completely messed it up."
Right. Felix > >>> - Vladimir mentioned LatencyUtils in this PR: >>> - Used in MicroMeter >>> - Based on Gil Tene work who is master of CO related issues as >>> long as other titles >>> >>> >>> *PROPOSED ACTION PLAN:* >>> >>> - We'll start our work using LatencyUtils which seems interesting as >> it >>> provides a PauseDetector which will be useful in our case >>> >>> >>> If you have any note on this, feel free to add your ideas in this thread. >> Have a look at the performance of the reports while the stats are >> collected. >> > Thanks > >> Felix >> >>> Regards >>> Philippe M. >>> UbikLoadPack Team >>> >>> >>> >>> >>> >>> >>> <https://www.openstreetmap.org/#map=18/50.69454/3.16455> >>> >
