On Fri, Sep 21, 2018 at 11:35 AM Dave Taht <dave.t...@gmail.com> wrote: > > As it happens, I'm primarily trying to get to the root causes of > babeld going flaky on me, and my primary purpose was to test babeld > 1.8.3 while under load, but I have a few observations in this dataset. > > It is WAY easier if you just download the tarball and use flent to > look at the various graphs. > > so: > > wget http://flent-fremont.bufferbloat.net/~d/babel-ecn.tgz > > or browse: http://flent-fremont.bufferbloat.net/~d/babel-ecn/ > > I started writing up things, with pictures, and so on, and that > started to get long, and I want to finish blowing babel up (if I can) > before I can safely deploy it so... > > The test was client <-> 100Mbit bottleneck <-> server > with ecn on or off on cubic tcp. > > I ran most of them at a higher resolution (-s .02). See the included > test script for more details. Running at this resolution required many > minutes and 7GB's of memory to post-process the files. > > I need to go fix tc-iterate so I can get queue depths again. I'd also > like to add irtt support to tcp_nup - I'm A) mostly interested in > making babel fail, and B) tcp flows > > I did collect a ton of interesting statistics on the tcp flows. The > tcp rtt CDFs, in particular. > > The files with no qdisc mentioned are cake. > > 0) I did the fq_codel_fast tests using memlimit 4M (the openwrt > default, so far as I know(?) > > 1) At this workload, pie's ecn support gets disabled almost completely > - the drop probability cracks 10% and it drops away... something like > 370 packets marked vs 49000 dropped. > > * You can see cake doing quite well vis a vis fq_codel, but you can > also see that the RTT is inflated in either case with ecn on vs off. > > * You can see the effects of hash collisions on codel - one test had a > major hash collision on the measurement flow. > > * Probably the most interesting result (and one reason why I started > fiddling with the bulk dropper code in the first place) > > was cake vs fq_codel_fast, attached.
To clarify, the ruler flat line is cake. The other line is fq_codel and it's collisions. > But: DO suck down these files and peruse for yourself. > > -- > > Dave Täht > CTO, TekLibre, LLC > http://www.teklibre.com -- Dave Täht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619 _______________________________________________ Cake mailing list Cake@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cake