On madrid.cs.unh.edu Most of the time during application "madrid" is running, the CPU is 97%(or higher) idle application "madrid" is actually running "blastclient" test. It also send control message to router "dublin" to change the kernel parameter( dropping rate ) after 10 times experiments on a given dropping rate. to notice kernel to record the TCP packet loss during last 100000 packet. A snapshot of "top" result: 11:32am up 17 days, 17:51, 3 users, load average: 0.00, 0.00, 0.00 51 processes: 50 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.0% user, 0.7% system, 0.0% nice, 99.2% idle Mem: 517196K av, 511816K used, 5380K free, 21976K shrd, 457992K buff Swap: 1028120K av, 4408K used, 1023712K free 12660K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 31373 root 13 0 1024 1024 820 R 0.5 0.1 0:01 top 31402 lin 4 0 472 472 396 S 0.1 0.0 0:00 blastclient 1 root 0 0 124 76 52 S 0.0 0.0 0:05 init 2 root 0 0 0 0 0 SW 0.0 0.0 0:00 kflushd 3 root 0 0 0 0 0 SW 0.0 0.0 0:17 kupdate 4 root 0 0 0 0 0 SW 0.0 0.0 0:00 kpiod 5 root 0 0 0 0 0 SW 0.0 0.0 0:13 kswapd 415 root 0 0 348 328 256 S 0.0 0.0 0:01 syslogd 425 root 0 0 340 0 0 SW 0.0 0.0 0:00 klogd 440 rpc 0 0 88 0 0 SW 0.0 0.0 0:00 portmap 456 root 0 0 0 0 0 SW 0.0 0.0 0:00 lockd 457 root 0 0 0 0 0 SW 0.0 0.0 0:00 rpciod 467 rpcuser 0 0 96 0 0 SW 0.0 0.0 0:00 rpc.statd 519 nobody 0 0 392 372 296 S 0.0 0.0 0:00 identd 523 nobody 0 0 392 372 296 S 0.0 0.0 0:00 identd 524 nobody 0 0 392 372 296 S 0.0 0.0 0:00 identd 525 nobody 0 0 392 372 296 S 0.0 0.0 0:00 identd 526 nobody 0 0 392 372 296 S 0.0 0.0 0:00 identd 538 daemon 0 0 116 60 52 S 0.0 0.0 0:00 atd 553 root 0 0 492 384 284 S 0.0 0.0 0:00 xinetd 570 root 0 0 1836 1836 1580 S 0.0 0.3 0:00 ntpd 586 root 0 0 272 128 44 S 0.0 0.0 0:00 sshd 607 lp 0 0 268 188 160 S 0.0 0.0 0:00 lpd 651 root 0 0 596 272 236 S 0.0 0.0 0:00 sendmail 667 root 0 0 120 72 56 S 0.0 0.0 0:00 gpm 682 root 1 0 160 116 72 S 0.0 0.0 0:00 crond 715 xfs 0 0 3660 1928 496 S 0.0 0.3 0:01 xfs 741 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 742 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 743 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 744 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 745 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 746 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty ........ On dublin.cs.unh.edu Most of the time during application "dublin" is running, the CPU is 97%(or higher) idle Application "dublin" runs a deamon on interface eth0. it receives control message from madrid:eth0 and change kernel dropping rate or record TCP packets loss by manipulating /proc file system. A snapshot of "top" result: 12:47pm up 19 days, 12:23, 2 users, load average: 0.00, 0.00, 0.00 43 processes: 42 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.0% user, 1.1% system, 0.0% nice, 98.8% idle Mem: 255084K av, 149592K used, 105492K free, 0K shrd, 12244K buff Swap: 1028120K av, 0K used, 1028120K free 65840K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 30275 root 14 0 1020 1020 820 R 0.1 0.3 0:01 top 1 root 8 0 536 536 464 S 0.0 0.2 0:03 init 2 root 9 0 0 0 0 SW 0.0 0.0 0:00 keventd 3 root 19 19 0 0 0 SWN 0.0 0.0 0:00 ksoftirqd_CPU0 4 root 9 0 0 0 0 SW 0.0 0.0 0:00 kswapd 5 root 9 0 0 0 0 SW 0.0 0.0 0:00 bdflush 6 root 9 0 0 0 0 SW 0.0 0.0 0:00 kupdated 7 root 9 0 0 0 0 SW 0.0 0.0 0:00 khubd 8 root 9 0 0 0 0 SW 0.0 0.0 0:00 khttpd manager 407 root 9 0 600 600 500 S 0.0 0.2 0:01 syslogd 417 root 9 0 612 612 460 S 0.0 0.2 0:01 klogd 432 rpc 9 0 568 568 480 S 0.0 0.2 0:00 portmap 456 rpcuser 9 0 656 656 560 S 0.0 0.2 0:00 rpc.statd 508 nobody 9 0 724 724 608 S 0.0 0.2 0:00 identd 509 nobody 9 0 724 724 608 S 0.0 0.2 0:00 identd 510 nobody 9 0 724 724 608 S 0.0 0.2 0:00 identd 514 nobody 9 0 724 724 608 S 0.0 0.2 0:00 identd 515 nobody 9 0 724 724 608 S 0.0 0.2 0:00 identd 527 daemon 9 0 580 580 504 S 0.0 0.2 0:00 atd 536 root 9 0 1168 1168 944 S 0.0 0.4 0:00 sshd 556 root 8 0 1000 988 788 S 0.0 0.3 0:00 xinetd 572 lp 9 0 876 876 748 S 0.0 0.3 0:00 lpd 616 root 8 0 1412 1412 1032 S 0.0 0.5 0:00 sendmail 632 root 9 0 488 488 424 S 0.0 0.1 0:00 gpm 647 root 9 0 640 640 552 S 0.0 0.2 0:00 crond 680 xfs 9 0 2920 2920 784 S 0.0 1.1 0:00 xfs 692 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 693 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 694 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 695 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 696 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 697 root 9 0 432 432 364 S 0.0 0.1 0:00 mingetty 29384 root 9 0 972 972 792 S 0.0 0.3 0:00 in.rlogind On prague.cs.unh.edu there is only one user application: blastserver 1026 CPU usage: 99%(or more) idle A snapshot of "top" result while experiments is doing: 11:57am up 28 days, 21:10, 2 users, load average: 0.00, 0.00, 0.00 38 processes: 37 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.0% user, 0.3% system, 0.0% nice, 99.6% idle Mem: 257660K av, 234908K used, 22752K free, 12020K shrd, 204440K buff Swap: 1028120K av, 4536K used, 1023584K free 8064K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 17690 root 10 0 1016 1016 820 R 0.3 0.3 0:00 top 1 root 0 0 172 132 104 S 0.0 0.0 0:05 init 2 root 0 0 0 0 0 SW 0.0 0.0 0:06 kflushd 3 root 0 0 0 0 0 SW 0.0 0.0 1:48 kupdate 4 root 0 0 0 0 0 SW 0.0 0.0 0:00 kpiod 5 root 0 0 0 0 0 SW 0.0 0.0 0:01 kswapd 406 root 0 0 348 328 256 S 0.0 0.1 0:00 syslogd 416 root 0 0 340 0 0 SW 0.0 0.0 0:00 klogd 431 rpc 0 0 80 0 0 SW 0.0 0.0 0:00 portmap 457 nobody 0 0 124 24 20 S 0.0 0.0 0:00 identd 459 nobody 0 0 124 24 20 S 0.0 0.0 0:00 identd 460 nobody 0 0 124 24 20 S 0.0 0.0 0:00 identd 463 nobody 0 0 124 24 20 S 0.0 0.0 0:00 identd 464 nobody 0 0 124 24 20 S 0.0 0.0 0:00 identd 476 daemon 0 0 116 60 52 S 0.0 0.0 0:00 atd 493 root 0 0 1836 1836 1580 S 0.0 0.7 0:00 ntpd 503 root 0 0 724 632 556 S 0.0 0.2 0:00 sshd 523 root 0 0 488 380 304 S 0.0 0.1 0:00 xinetd 539 lp 0 0 128 0 0 SW 0.0 0.0 0:00 lpd 583 root 0 0 596 272 236 S 0.0 0.1 0:00 sendmail 599 root 0 0 100 52 40 S 0.0 0.0 0:00 gpm 614 root 0 0 160 116 72 S 0.0 0.0 0:00 crond 647 xfs 0 0 2164 52 40 S 0.0 0.0 0:00 xfs 660 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 661 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 662 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 663 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 664 root 0 0 68 0 0 SW 0.0 0.0 0:00 mingetty 24909 root 0 0 432 432 364 S 0.0 0.1 0:00 mingetty 17278 root 0 0 972 972 792 S 0.0 0.3 0:00 in.rlogind 17279 root 0 0 1160 1160 944 S 0.0 0.4 0:00 login 17280 lin 0 0 1284 1284 948 S 0.0 0.4 0:00 bash 17299 lin 6 0 596 596 460 S 0.0 0.2 3:12 blastserver