[net-perf] impact of testing on other services?

[Michael Sinatra]

On Fri, 24 Jun 2005, John Haskins wrote:

> Let me pose a question while I wait for my kernel to build (again)...
>
> I assume that folks are using their routing configurations to be sure
> that the bwctl tests go over the HPR network, not DC.  Our campus,
> and I think several others, normally prefers the HPR path for all traffic
> to other HPR-attached sites.
>
> Are folks moving 'normal' traffic to DC in order to lessen the potential
> impact on production traffic of filling the HPR links with test traffic?
> Or has the impact of testing been below the radar so far?

We haven't thought much about moving traffic to DC, as the testing impact 
has generally been under the radar, at least from a user perspective.

However, I thought I would present a perhaps-interesting result.  I 
started pinging the UCSC webserver from my office workstation.  I then 
scheduled a bwctl test between our bwctl server and UCSC's bwctl server. 
Our bwctl server is not the same machine as my workstation, and I assume 
that UCSC isn't running its bwctl server on its main website.  You can 
clearly see the jump in latency during the 10-second bwctl test:

64 bytes from 128.114.124.7: icmp_seq=35 ttl=120 time=3.824 ms
64 bytes from 128.114.124.7: icmp_seq=36 ttl=120 time=3.807 ms
64 bytes from 128.114.124.7: icmp_seq=37 ttl=120 time=3.841 ms
64 bytes from 128.114.124.7: icmp_seq=38 ttl=120 time=4.027 ms
64 bytes from 128.114.124.7: icmp_seq=39 ttl=120 time=3.831 ms
64 bytes from 128.114.124.7: icmp_seq=40 ttl=120 time=4.275 ms
64 bytes from 128.114.124.7: icmp_seq=41 ttl=120 time=4.244 ms
64 bytes from 128.114.124.7: icmp_seq=42 ttl=120 time=3.989 ms
64 bytes from 128.114.124.7: icmp_seq=43 ttl=120 time=3.836 ms
64 bytes from 128.114.124.7: icmp_seq=44 ttl=120 time=3.796 ms
64 bytes from 128.114.124.7: icmp_seq=45 ttl=120 time=3.822 ms
64 bytes from 128.114.124.7: icmp_seq=46 ttl=120 time=3.764 ms
64 bytes from 128.114.124.7: icmp_seq=47 ttl=120 time=3.784 ms
64 bytes from 128.114.124.7: icmp_seq=48 ttl=120 time=3.768 ms
64 bytes from 128.114.124.7: icmp_seq=49 ttl=120 time=3.757 ms
64 bytes from 128.114.124.7: icmp_seq=50 ttl=120 time=3.838 ms
64 bytes from 128.114.124.7: icmp_seq=51 ttl=120 time=3.806 ms
64 bytes from 128.114.124.7: icmp_seq=52 ttl=120 time=7.575 ms
64 bytes from 128.114.124.7: icmp_seq=53 ttl=120 time=18.251 ms
64 bytes from 128.114.124.7: icmp_seq=54 ttl=120 time=18.383 ms
64 bytes from 128.114.124.7: icmp_seq=55 ttl=120 time=18.647 ms
64 bytes from 128.114.124.7: icmp_seq=56 ttl=120 time=18.757 ms
64 bytes from 128.114.124.7: icmp_seq=57 ttl=120 time=19.006 ms
64 bytes from 128.114.124.7: icmp_seq=58 ttl=120 time=18.577 ms
64 bytes from 128.114.124.7: icmp_seq=59 ttl=120 time=18.690 ms
64 bytes from 128.114.124.7: icmp_seq=60 ttl=120 time=18.406 ms
64 bytes from 128.114.124.7: icmp_seq=61 ttl=120 time=17.928 ms
64 bytes from 128.114.124.7: icmp_seq=62 ttl=120 time=3.999 ms
64 bytes from 128.114.124.7: icmp_seq=63 ttl=120 time=3.793 ms
64 bytes from 128.114.124.7: icmp_seq=64 ttl=120 time=3.861 ms
64 bytes from 128.114.124.7: icmp_seq=65 ttl=120 time=4.142 ms
64 bytes from 128.114.124.7: icmp_seq=66 ttl=120 time=3.760 ms
64 bytes from 128.114.124.7: icmp_seq=67 ttl=120 time=3.768 ms
64 bytes from 128.114.124.7: icmp_seq=68 ttl=120 time=3.757 ms
64 bytes from 128.114.124.7: icmp_seq=69 ttl=120 time=3.746 ms
64 bytes from 128.114.124.7: icmp_seq=70 ttl=120 time=3.786 ms
64 bytes from 128.114.124.7: icmp_seq=71 ttl=120 time=3.763 ms
64 bytes from 128.114.124.7: icmp_seq=72 ttl=120 time=4.051 ms
64 bytes from 128.114.124.7: icmp_seq=73 ttl=120 time=3.849 ms

By the way, here's the bwctl results:

RECEIVER START
3328637209.297186: /usr/local/bin/iperf -B 128.114.0.205 -P 1 -s -f b -m 
-p 5001 -w 4194304 -t 10 -i 2
------------------------------------------------------------
Server listening on TCP port 5001
Binding to local address 128.114.0.205
TCP window size: 4194304 Byte
------------------------------------------------------------
[ 14] local 128.114.0.205 port 5001 connected with 192.101.42.26 port 5001
[ 14]  0.0- 2.0 sec  227090432 Bytes  908361728 bits/sec
[ 14]  2.0- 4.0 sec  242130944 Bytes  968523776 bits/sec
[ 14]  4.0- 6.0 sec  241016832 Bytes  964067328 bits/sec
[ 14]  6.0- 8.0 sec  240885760 Bytes  963543040 bits/sec
[ 14]  8.0-10.0 sec  242008064 Bytes  968032256 bits/sec
[ 14]  0.0-10.0 sec  1194991616 Bytes  954534478 bits/sec
[ 14] MSS size 8192 bytes (MTU 8232 bytes, unknown interface)
RECEIVER END

michael