[rrd-users] RRDTool not accepting any updates (NaN instead)

[Tobias Oetiker]

Wouter,

Today Wouter van Eekelen wrote:

> I'm currently using these create parameters now:
> --
>                 shell_exec("/usr/bin/rrdtool create ".$rrd_file." -s 300 \
>                                 DS:ds0:DERIVE:600:0:4294967295 \
>                                 DS:ds1:DERIVE:600:0:4294967295 \
> --
>
> The issue is that on one of the switch ports (which is doing 80 mbit), the
> counter wrap is mistaken and outputs 'nan'.
> The manual says: 'so for high bandwidth interfaces and a 32bit counter,
> DERIVE with min=0 is probably preferable.', so what am I doing wrong?

then use COUNTER ...

even better, use snmpv2 counters since they will wrapp less
frequently

cheers
tobi
>
> It wrapped at 1291502400 (went from 8122065 to 7924308):
> --
> [root at server1]# rrdtool fetch port24.rrd --start=-2000 AVERAGE
>                             ds0                 ds1
>
> 1291502100: 8.2063600757e+06 2.2500898666e+06
> 1291502400: nan 2.2546759116e+06
> 1291502700: 7.7745353463e+06 2.2562329465e+06
> 1291503000: 7.7928605384e+06 2.2955885537e+06
> 1291503300: 8.0216481999e+06 2.3222729101e+06
> 1291503600: 8.0522287038e+06 2.4876925386e+06
> 1291503900: 8.0878106732e+06 3.6759178677e+06
> 1291504200: nan nan
>
> On Sat, Dec 4, 2010 at 10:33 PM, Tobias Oetiker <tobi at oetiker.ch> wrote:
>
> > Hi Wouter,
> >
> > Today Wouter van Eekelen wrote:
> >
> > > That works a lot better indeed. Is there a reason updatev can't output
> > such
> > > information?
> > > If it would just tell me 'mrhb expired, assuming nan' I would have solved
> > > this way faster.
> >
> > :-) it could ... especially if someone was to implement a --verbose
> > switch which would enable such errors ...
> >
> > cheers
> > tobi
> >
> > >
> > > On Sat, Dec 4, 2010 at 10:08 PM, Tobias Oetiker <tobi at oetiker.ch> wrote:
> > >
> > > > Wouter,
> > > >
> > > > Today Wouter van Eekelen wrote:
> > > >
> > > > > Aren't my updates incremental? The second update has quite a higher
> > value
> > > > > than the first one, yet it's still NaN.
> > > >
> > > > it seems to me that you have set the mrhb to 5 seconds ... while
> > > > the step size is 60 seconds ... this is possible but it requires
> > > > you to update the rrd at least every 5 seconds ...
> > > >
> > > > cheers
> > > > tobi
> > > >
> > > > >
> > > > > On Sat, Dec 4, 2010 at 9:23 PM, Steve Shipway <
> > s.shipway at auckland.ac.nz
> > > > >wrote:
> > > > >
> > > > > >   Your DS are of type 'derive', with a minimum value of 0.
> >  'Derive'
> > > > > > stores the rate of change of the variable, IE (( x -
> > > > x(prev))/(t-t(prev)))
> > > > > > This means you'll need at least two sequential updates, which must
> > be
> > > > > > increasing (in order to get a valid positive derivitive) before
> > you'll
> > > > see
> > > > > > anything stored in the RRAs.  Since your step is 60s, this means
> > two
> > > > > > increasing updates about 1min apart, and more than 2 (4, 13, 145)
> > if
> > > > you
> > > > > > want any of the RRAs with a cdp of more than 1 to show a value
> > (since
> > > > your
> > > > > > XFF is 0.5).
> > > > > >
> > > > > > Steve
> > > > > >
> > > > > >  *Steve Shipway*
> > > > > > University of Auckland ITS
> > > > > > *UNIX Systems Design Lead*
> > > > > > s.shipway at auckland.ac.nz
> > > > > > Ph: +64 9 373 7599 ext 86487
> > > > > > **
> > > > > >   ------------------------------
> > > > > > *From:* rrd-users-bounces+s.shipway=auckland.ac.nz@
> > lists.oetiker.ch
> > > > [rrd-users-bounces+s.shipway=
> > > > > > auckland.ac.nz at lists.oetiker.ch] on behalf of Wouter van Eekelen [
> > > > > > wouter.van.eekelen at serverffs.com]
> > > > > > *Sent:* Sunday, 5 December 2010 8:09 a.m.
> > > > > > *To:* rrd-users at lists.oetiker.ch
> > > > > > *Subject:* [rrd-users] RRDTool not accepting any updates (NaN
> > instead)
> > > > > >
> > > > > >  I'm having a huge trouble with RRDtool, all updates I'm doing are
> > > > > > accepted as 'NaN'
> > > > > > Here is are all commands with output:
> > > > > >
> > > > > >
> > > > >
> > > >
> > > > --
> > > > Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
> > > > http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900
> > > >
> > >
> >
> > --
> > Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
> > http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900
> >
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900