But 444.35 + 443.65 = 888, no? > On Nov 27, 2017, at 18:33, Dave Taht <[email protected]> wrote: > > georgios > > the result you got was "fair", but you shoul have seen something > closer to 900mbit than 400. > > On Mon, Nov 27, 2017 at 8:17 AM, Georgios Amanakis <[email protected]> > wrote: >> Dear Pete, >> >> I am trying to replicate the unfair behaviour you are seeing with >> dual-{src,dst}host, albeit on different hardware and I am getting a fair >> distribution. Hardware are Xeon E3-1220Lv2 (router), i3-3110M(Clients). All >> running Archlinux, latest cake and patched iproute2-4.14.1, connected with >> Gbit ethernet, TSO/GSO/GRO enabled. >> >> Qdisc setup: >> ---------------- >> Router: >> qdisc cake 8003: dev ens4 root refcnt 2 bandwidth 900Mbit diffserv3 >> dual-dsthost rtt 100.0ms raw >> >> Client A(kernel default): >> qdisc fq_codel 0: dev eno2 root refcnt 2 limit 10240p flows 1024 quantum >> 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn >> >> Client B (kernel default): >> qdisc fq_codel 0: dev enp1s0 root refcnt 2 limit 10240p flows 1024 quantum >> 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn >> ---------------- >> >> >> Cli: >> ---------------- >> Router: >> netserver & >> >> Client A: >> flent tcp_1down -H router >> >> Client B: >> flent tcp_12down -H router >> ---------------- >> >> >> Results: >> ---------------- >> Router: >> qdisc cake 8003: root refcnt 2 bandwidth 900Mbit diffserv3 dual-dsthost rtt >> 100.0ms raw >> Sent 7126680117 bytes 4725904 pkt (dropped 10, overlimits 4439745 requeues >> 0) >> backlog 0b 0p requeues 0 >> memory used: 1224872b of 15140Kb >> capacity estimate: 900Mbit >> Bulk Best Effort Voice >> thresh 56250Kbit 900Mbit 225Mbit >> target 5.0ms 5.0ms 5.0ms >> interval 100.0ms 100.0ms 100.0ms >> pk_delay 14us 751us 7us >> av_delay 2us 642us 1us >> sp_delay 1us 1us 1us >> pkts 109948 4601651 14315 >> bytes 160183242 6964893773 1618242 >> way_inds 0 21009 0 >> way_miss 160 188 5 >> way_cols 0 0 0 >> drops 0 10 0 >> marks 0 0 0 >> ack_drop 0 0 0 >> sp_flows 0 1 1 >> bk_flows 1 0 0 >> un_flows 0 0 0 >> max_len 7570 68130 1022 >> >> >> Client A: >> avg median # data pts >> Ping (ms) ICMP : 0.11 0.08 ms 350 >> TCP download : 443.65 430.38 Mbits/s 301 >> >> >> Client B: >> avg median # data pts >> Ping (ms) ICMP : 0.09 0.06 ms 350 >> TCP download avg : 37.03 35.87 Mbits/s 301 >> TCP download sum : 444.35 430.40 Mbits/s 301 >> TCP download::1 : 37.00 35.87 Mbits/s 301 >> TCP download::10 : 37.01 35.87 Mbits/s 301 >> TCP download::11 : 37.02 35.87 Mbits/s 301 >> TCP download::12 : 37.00 35.87 Mbits/s 301 >> TCP download::2 : 37.03 35.87 Mbits/s 301 >> TCP download::3 : 36.99 35.87 Mbits/s 301 >> TCP download::4 : 37.03 35.87 Mbits/s 301 >> TCP download::5 : 37.07 35.87 Mbits/s 301 >> TCP download::6 : 37.00 35.87 Mbits/s 301 >> TCP download::7 : 37.12 35.87 Mbits/s 301 >> TCP download::8 : 37.05 35.87 Mbits/s 301 >> TCP download::9 : 37.03 35.87 Mbits/s 301 >> ---------------- >> >> Does this suggest that it is indeed a problem of an underpowered CPU in your >> case? >> >> George >> >> >> On Mon, Nov 27, 2017 at 10:53 AM, Pete Heist <[email protected]> wrote: >>> >>> >>> On Nov 27, 2017, at 3:48 PM, Jonathan Morton <[email protected]> >>> wrote: >>> >>> It's not at all obvious how we'd detect that. Packets are staying in the >>> queue for less time than the codel target, which is exactly what you'd get >>> if you weren't saturated at all. >>> >>> That makes complete sense when you put it that way. Cake has no way of >>> knowing why the input rate is lower than expected, even if it’s part of the >>> cause. >>> >>> I don’t think flent can know this either. It can’t easily know the cause >>> for its total output to be lower than expected. >>> >>> All I know is, this is a common problem in deployments, particularly on >>> low-end hardware like ER-Xs, that can be tricky for users to figure out. >>> >>> I don’t even think monitoring CPU in general would work. The CPU could be >>> high because it’s doing other calculations, but there’s still enough for >>> cake at a low rate, and there’s no need to warn in that case. I’d be >>> interested in any ideas on how to know this is happening in the system as a >>> whole. So far, there are just various clues that one needs to piece together >>> (no or few drops or marks, less total throughput that expected, high cpu >>> without other external usage, etc). Then it needs to be proven with a test. >>> >>> Anyway thanks, your clue was what I needed! I need to remember to review >>> the qdisc stats when something unexpected happens. >>> >>> _______________________________________________ >>> Cake mailing list >>> [email protected] >>> https://lists.bufferbloat.net/listinfo/cake >>> >> >> >> _______________________________________________ >> 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
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