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Diffstat (limited to 'Examples/tcpwdist_example.txt')
| -rw-r--r-- | Examples/tcpwdist_example.txt | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Examples/tcpwdist_example.txt b/Examples/tcpwdist_example.txt new file mode 100644 index 000000000000..02a392ce55a1 --- /dev/null +++ b/Examples/tcpwdist_example.txt @@ -0,0 +1,70 @@ +The following is a demonstration of the tcpwdist.d script. + + +Here the tcpwdist.d script is run for a few seconds then Ctrl-C is hit, + + # tcpwdist.d + Tracing... Hit Ctrl-C to end. + ^C + PID: 15300 CMD: finger @mars\0 + + value ------------- Distribution ------------- count + -1 | 0 + 0 |@@@@@@@@@@@@@@@@@@@@ 1 + 1 | 0 + 2 |@@@@@@@@@@@@@@@@@@@@ 1 + 4 | 0 + + PID: 4967 CMD: /usr/lib/ssh/sshd\0 + + value ------------- Distribution ------------- count + 16 | 0 + 32 |@@@@@@@@@@@@@@@@@@@@ 1 + 64 |@@@@@@@@@@@@@@@@@@@@ 1 + 128 | 0 + + PID: 9172 CMD: /usr/lib/ssh/sshd\0 + + value ------------- Distribution ------------- count + 16 | 0 + 32 |@@@@@@@@ 4 + 64 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 14 + 128 | 0 + 256 | 0 + 512 |@@ 1 + 1024 | 0 + + PID: 15301 CMD: rcp 1Mb.gz mars:/tmp\0 + + value ------------- Distribution ------------- count + 0 | 0 + 1 |@ 2 + 2 |@ 1 + 4 | 0 + 8 |@ 2 + 16 |@ 2 + 32 | 0 + 64 | 0 + 128 | 0 + 256 | 0 + 512 | 0 + 1024 | 0 + 2048 | 0 + 4096 | 0 + 8192 | 0 + 16384 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 64 + 32768 | 0 + +In the above output we can see the "rcp" command dominates, sending +large writes (16 to 31 Kb) 64 times. The "sshd" ssh daemons each sent +several smaller writes, from 32 to 127 bytes - which corresponds to +command line activity (eg, screen width of 80 bytes). The finger command +sent 2 bytes once, and zero data bytes once. + +These values are the TCP write payload sizes. + +The writes from the "rcp" command seem unusual at over 16 Kb each, when +this is an Ethernet network with an MTU of 1500 bytes. The reason is that +at this point the data has not yet been broken down into MTU sized packets, +so we are looking at the applications behaviour as it writes to TCP. + |