Back to Back Performance Tests - PING
The purpose of these tests is to determine the latency on the Intel GigE cards in the mbng machines. By doing this, we hope to be able to derive baseline performances of the cards in order to better understand the performance in the WAN.
Using standard ping (as supplied in Redhat 7.2), a set of scripts were used to create tables of latencies for various packet sizes and interpacket times.
The scripts are:
do_packetsize.pl - a script to alter the packet sizes of ping packets
do_packetsize-vs-interval.pl - used by superusers, it enables the interpacket time between consequtive packets to be altered.
do_txqueuelen.pl - enables the txqueuelen parameter as defined in ifconfig to be altered for various packetsize-vs-interval tests.
Tests were performed back-to-back from mbng2 to mbng3. Both machines were configured identically with Redhat 7.2 and kernel version 2.4.19 with Web100 alpha 2.1.
Experiment 0: Determine the measurement parameters
We altered the number of packets sent and determined the statistical variation of the samples. We used interpacket rate of 1 ping every 1millisecond and varied the number of packets from 5 to 1000 in steps of 5.
[root@mbng2 ping]# ./do_number.pl -d 192.168.0.3 -s 16 -c 2 -i 1 -n 5..1000:5
-o summary.log -f number
log file in tsv
So we choose to send 80 packets as it appears to be have the least variation with least number of packets sent.
Experiment 1: Alter packet size
./do_packetsize.pl -d 192.168.0.3 -c 2 -i 1 -n 80 -s 16..3500:10 -f packetsize -o summary-last.log
This has the following regions:
|© 2001-2003, Yee-Ting Li, email: email@example.com,
Tel: +44 (0) 20 7679 1376, Fax: +44 (0) 20 7679 7145
Room D14, High Energy Particle Physics, Dept. of Physics & Astronomy, UCL, Gower St, London, WC1E 6BT