you are making me pull out my mrtg stats, I'll post one. In the debloating universe, 5 minute averages really obscure the bufferbloat problem. What's important are drops/marks, reschedules, queue depths, and overlimits. I get about 3000 drops/day (debloats). I wish I could extrapolate what that and the reschedules means in terms of induced latency on other flows, easily. On Fri, Sep 7, 2018 at 3:00 AM Pete Heist <[email protected]> wrote: > > > On Sep 7, 2018, at 1:03 AM, Jonathan Morton <[email protected]> wrote: > > On 7 Sep, 2018, at 1:37 am, Pete Heist <[email protected]> wrote: > > This router is an old ALIX with kernel 2.6.26, but on the other hand it does > have hfsc + esfq (a variant of sfq with host fairness) deployed, so if it’s > actually controlling the queue, one might suspect that sfq it could control > inter-flow latency at least somewhat. > > > ESFQ has two important faults: it doesn't explicitly control the length of > individual queues (only tail-drops when a global limit is reached), and it > suffers from hash collisions at the full "birthday problem" rate. So some of > your measurement traffic is likely colliding with real traffic and suffering > accordingly. > > > Ah, ok, that is important. > > That still makes ESFQ far better than a dumb FIFO. > > > I’ve heard tales of the way things were. > > As a contrast, the router I’m on: > https://www.heistp.net/downloads/vysina_ping.pdf The big difference here is > this router’s uplink is licensed spectrum full-duplex 100Mbit, whereas Jerab > from earlier is 5GHz WiFi (2x NSM5). The shift around June was an upgrade > from ALIX to APU. > > I haven’t seen evidence yet of backhaul links running at saturation for long > periods. When I watch throughputs in real-time I do see pulses though that > probably don't show up in the long-term MRTG throughput graphs. I wonder what > queue lengths look like at millisecond resolution during these events. > _______________________________________________ > Cake mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/cake
-- Dave Täht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619 _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
