Rick, Yesterday Rick Jones wrote:
> I've come to rrd via ntop (http://www.ntop.org/) which I'm looking at in > the context of sFlow (http://www.sflow.org/) and receiving sFlow counter > samples as often as once per second per interface. RRD and its use by > ntop seems rather ideal in that it has the concept of keeping so many > samples at fine resolution, so many at a coarser and so on. I've (or at > least I think I have) cranked ntop's storage of values into RRD down to > once per second, but the appearance of messages such as: > > > > Mon Apr 18 15:06:07 2011 **WARNING** RRD: > > rrd_update(/usr/local/var/ntop/rrd/interfaces/sFlow-device.2/sFlow/48/ifOutMulticastPkts.rrd) > > error: > > /usr/local/var/ntop/rrd/interfaces/sFlow-device.2/sFlow/48/ifOutMulticastPkts.rrd: > > illegal attempt to update using time 1303164367 when last update time > > is 1303164367 (minimum one second step) > > (Which may have appeared even before the rate was cranked down to every > second, I must confess I'm not quite sure one way or the other) has me > concerned about operations at the limit - in other words, ostensibly I > have values going into the rrd once per second, but suppose that > flutters back and forth across the second boundary? Is it likely that > is what happened above? That the update happened to hit just before the > second rolled-over? > > In this instance I happen to be running 4.0.3 of ntop compiled from source, > and: > > raj@tardy:~$ dpkg -l | grep rrd > ii librrd-dev 1.4.3-1ubuntu1 time-series data storage and display system > (development) > ii librrd4 1.4.3-1ubuntu1 time-series data storage and display system > (runtime library) > ii rrdtool 1.4.3-1ubuntu1 time-series data storage and display system > (programs) you can input time with millisecond precision, then this will not happen 1303164367.002 1303164367.393 cheers tobi > > for the RRD bits. > > thanks, > > rick jones > > _______________________________________________ > rrd-users mailing list > [email protected] > https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users > > -- Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland http://it.oetiker.ch [email protected] ++41 62 775 9902 / sb: -9900 _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
