Hi Rick, Yesterday Rick Jones wrote:
> At the moment, I am working with a device that should be using 64-bit > wide counters in its report of octets via sFlow, but is only using 32 > bits. Through this device I am sending a constant stream of netperf > UDP_STREAM reporting a very steady 961 Mbit/s (and change, occasionally > it will report 960.97 Mbit/s) so I suspect the device is being driven at > link-rate. It is reporting these counters every 30 seconds, link-rate 1 > GbE networking should wrap a 32-bit octet counter in ~40 seconds, so I > believe I should never have more than one counter wrap per sampling > interval. I am using a step size of one second. > > I was seeing large gaps in my graphs so I isolated the one value I was > looking at from the rest, and captured some data from the device and fed > it to an rrd created with: > > rrdtool create test.rrd --start 1308092201 --step 1 DS:foo:DERIVE:60:0:U > RRA:AVERAGE:0.5:1:86400 > > fed it with the data I extracted from a tcpdump trace of the sFlow PDUs: > > raj@tardy:~/rrdbug$ cat update.sh > rrdtool update test.rrd 1308092202.610:441241050 > rrdtool update test.rrd 1308092232.610:4141751743 > rrdtool update test.rrd 1308092262.609:3546818048 > rrdtool update test.rrd 1308092292.609:2952516367 > rrdtool update test.rrd 1308092322.609:2357287750 > rrdtool update test.rrd 1308092352.609:1762735341 > rrdtool update test.rrd 1308092382.609:1168026482 > rrdtool update test.rrd 1308092412.609:573080395 > rrdtool update test.rrd 1308092442.609:4273817690 > rrdtool update test.rrd 1308092472.608:3678028081 > rrdtool update test.rrd 1308092502.608:3082845004 > rrdtool update test.rrd 1308092532.608:2488508409 > rrdtool update test.rrd 1308092562.608:1892937812 > rrdtool update test.rrd 1308092592.608:1298202985 > rrdtool update test.rrd 1308092622.608:703006246 > rrdtool update test.rrd 1308092652.608:107385307 > rrdtool update test.rrd 1308092682.607:3807847414 > rrdtool update test.rrd 1308092712.607:3212758463 > rrdtool update test.rrd 1308092742.607:2617461450 > rrdtool update test.rrd 1308092772.607:2022995653 > rrdtool update test.rrd 1308092802.607:1428422068 > rrdtool update test.rrd 1308092832.607:833109777 > rrdtool update test.rrd 1308092862.607:239454268 > rrdtool update test.rrd 1308092892.607:3939282433 > rrdtool update test.rrd 1308092922.606:3343962564 > rrdtool update test.rrd 1308092952.606:2749615279 > rrdtool update test.rrd 1308092982.606:2154394252 > rrdtool update test.rrd 1308093012.606:1559964909 > rrdtool update test.rrd 1308093042.606:965307748 > rrdtool update test.rrd 1308093072.606:370349517 > rrdtool update test.rrd 1308093102.606:4070642890 > rrdtool update test.rrd 1308093132.606:3475575191 > rrdtool update test.rrd 1308093162.605:2881212866 > rrdtool update test.rrd 1308093192.605:2286174031 > rrdtool update test.rrd 1308093222.605:1691311682 > rrdtool update test.rrd 1308093252.605:1097016331 > rrdtool update test.rrd 1308093282.605:502274162 > rrdtool update test.rrd 1308093312.605:4201809009 > rrdtool update test.rrd 1308093342.605:3606613788 > rrdtool update test.rrd 1308093372.604:3012392733 > rrdtool update test.rrd 1308093402.604:2417665658 > > and then graphed that: > > rrdtool graph graph.png --end 1308093373 --start 1308092202 -w 1000 -h > 400 --step 1 -t "30 Second Counter Samples" -v "Octets/s" > --full-size-mode DEF:bar=test.rrd:foo:AVERAGE LINE2:bar#FF0000 > > The resulting graph is attached. Is there perhaps some issue in the > wrap code that results in the drop-outs? FWIW, I appear to see the same > behaviour if I use COUNTER rather than DERIVE. note that wrap detection is only active in COUNTER mode ... in any event, make sure you use the latest stable snapshot for testing ... I am not aware of any problem ... you may want to test with some crafterd data ... cheers tobi > rick jones > -- Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland http://it.oetiker.ch t...@oetiker.ch ++41 62 775 9902 / sb: -9900 _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
