Network throughput problems in RELENG_7
Abdullah Ibn Hamad Al-Marri
wearabnet at yahoo.ca
Sat Oct 27 07:51:14 PDT 2007
----- Original Message ----
> From: Matthew Reimer <mattjreimer at gmail.com>
> To: current at 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/
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