Date: Sat, 27 Oct 2007 07:51:13 -0700 (PDT) From: Abdullah Ibn Hamad Al-Marri <wearabnet@yahoo.ca> To: Matthew Reimer <mattjreimer@gmail.com> Cc: FreeBSD STABLE <freebsd-stable@freebsd.org> Subject: Re: Network throughput problems in RELENG_7 Message-ID: <619150.6364.qm@web33713.mail.mud.yahoo.com>
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----- Original Message ---- > From: Matthew Reimer <mattjreimer@gmail.com> > To: current@freebsd.org > Sent: Friday, October 26, 2007 7:10:55 PM > Subject: Network throughput problems in RELENG_7 > > I'm seeing a problem where a much faster quad-core host > running > RELENG_7 > serves many fewer netrate/http requests per second (175/sec) than an > old, busy, UP 6.0 host (828/sec). The problem seems to be related to > latency and connection setup, as it shows up dramatically over a link > with 50-60 ms latency. Can you help? > > "Gandalf" is the problem RELENG_7 host connected via em0 on a 100baseTX > full-duplex switch port. > "Boromir" is a 6.0 host for reference, connected via bge0 to another > 100baseTX full-duplex port on the same switch. > "Theoden" is a 6.2 host remote (50-60 ms away) from gandalf > and > boromir. > > Running tools/netrate/http against tools/netrate/httpd on gandalf and > boromir, serving a document with 35 bytes of content, I get this > (details including tcpdumps following my sig): > > dest dest > source boromir gandalf > ------ ------- ------- > theoden 828 175 > boromir - 18092 > gandalf 11493 - > > The problem occurs using ab as well, but is much less pronounced > when > -k > is used (enabling keepalive and presumably HTTP pipelining). This makes > me wonder if the problem might have something to do with connection > setups. > > I've verified that the switch port and the interface are configured > correctly (100baseTX full-duplex). I've also tried toggling polling and > the following sysctls, with no significant change: > > net.inet.tcp.tso > net.inet.tcp.newreno > net.inet.tcp.sack.enable > net.inet.tcp.inflight.enable > net.inet.tcp.syncookies_only > net.inet.tcp.syncookies > > What else can I try? > > Thanks for any help you can give. > > Matt > > > > > theoden-gandalf > =============== > > theoden:~$ /usr/obj/usr/src/tools/tools/netrate/http/http -s 2 > 216.193.240.4 > 1280 /short.html > 187 transfers/second > 0 errors/second > > tcpdump: > http://gandalf.vpop.net/~mreimer/theoden-gandalf-netrate.dump.gz > > --- > > theoden:~$ /usr/obj/usr/src/tools/tools/netrate/http/http -n 100 -s 2 > 216.193.240.4 1280 /short.html > 175 transfers/second > 0 errors/second > > tcpdump: > http://gandalf.vpop.net/~mreimer/theoden-gandalf-netrate-n100.dump.gz > > > > theoden-boromir > =============== > > theoden:~$ /usr/obj/usr/src/tools/tools/netrate/http/http -s 2 > 216.193.240.2 > 1280 /short.html > 272 transfers/second > 0 errors/second > > tcpdump: > http://boromir.vpop.net/~mreimer/theoden-boromir-netrate.dump.gz > > --- > > theoden:~$ /usr/obj/usr/src/tools/tools/netrate/http/http -n 100 -s 2 > 216.193.240.2 1280 /short.html > 828 transfers/second > 0 errors/second > > tcpdump: > http://boromir.vpop.net/~mreimer/theoden-boromir-netrate-n100.dump.gz > > > boromir-gandalf > =============== > > boromir: $ /usr/obj/usr/src/tools/tools/netrate/http/http -n 100 -s 2 > 216.193.240.4 1280 /short.html > 18092 transfers/second > 0 errors/second > > gandalf-boromir > =============== > > gandalf: $ /usr/obj/usr/src/tools/tools/netrate/http/http -n 100 -s 2 > 216.193.240.2 1280 /short.html > 11493 transfers/second > 0 errors/second > > > > > boromir sysctl and ifconfig: > > http://boromir.vpop.net/~mreimer/boromir.sysctl.gz > > > # ifconfig bge0 > bge0: flags=8843 mtu 1500 > options=1a > inet6 fe80::2e0:81ff:fe60:3925%bge0 prefixlen 64 scopeid 0x1 > inet 216.193.240.33 netmask 0xffffffff broadcast 216.193.240.33 > inet 216.193.240.34 netmask 0xffffffff broadcast 216.193.240.34 > inet 216.193.240.35 netmask 0xffffffff broadcast 216.193.240.35 > inet 216.193.240.36 netmask 0xffffffff broadcast 216.193.240.36 > inet 216.193.240.37 netmask 0xffffffff broadcast 216.193.240.37 > inet 216.193.240.17 netmask 0xffffffff broadcast 216.193.240.17 > inet 216.193.240.38 netmask 0xffffffff broadcast 216.193.240.38 > inet 216.193.240.39 netmask 0xffffffff broadcast 216.193.240.39 > inet 216.193.240.2 netmask 0xfffff800 broadcast 216.193.247.255 > inet 216.193.240.40 netmask 0xffffffff broadcast 216.193.240.40 > ether 00:e0:81:60:39:25 > media: Ethernet autoselect (100baseTX ) > status: active > > gandalf sysctl and ifconfig: > http://gandalf.vpop.net/~mreimer/gandalf.sysctl.gz > > # ifconfig em0 > em0: flags=8843 metric 0 mtu > 1500 > options=1cb > ether 00:30:48:33:96:a4 > inet 216.193.240.4 netmask 0xfffff800 broadcast 216.193.247.255 > inet 216.193.240.65 netmask 0xffffffff broadcast 216.193.240.65 > inet 216.193.240.66 netmask 0xffffffff broadcast 216.193.240.66 > inet 216.193.240.67 netmask 0xffffffff broadcast 216.193.240.67 > inet 216.193.240.68 netmask 0xffffffff broadcast 216.193.240.68 > media: Ethernet 100baseTX > status: active > Hello, When did you last time did you csup and buildworld? I saw some changes in tcp few days ago. Regards, -Abdullah Ibn Hamad Al-Marri Arab Portal http://www.WeArab.Net/ __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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