[rrd-users] How to find a grafics error?
Peter A. Menzel
prot_from_spam at famenzel.at
Sun Jun 14 21:17:34 CEST 2015
Hi Simon and David,
thank you for your hints!
I actually found some missing update values - that means not every second a new set of values.
Now I intent to tune the heartbeat value to 5 instead of 2,
and step size of 1 remaining constant...
So missing 1, 2 or 3 measures will not generate an *unknown* value in the RRD.
Do you think that is the right way?
Thank you and BR
Simon Hobson schrieb:
> Peter A. Menzel <prot_from_spam at famenzel.at> wrote:
> > Here is the setup script:
>> rrdtool create AgroFire.rrd --step 1 \
>> DS:KesselTemp:GAUGE:2:U:U \
>> RRA:AVERAGE:0.5:1:864000 \
> Can you be certain that you provide an update *every* second ?
> You have a step size of 1, and a heartbeat value of 2. That means that
> you can only have data 2 seconds old before it is considered unknown.
> What isn't clear is which side of the point the decision is taken as
> the manual says : > heartbeat defines the maximum number of seconds
> that may pass between
>> two updates of this data source before the value of the data source is
>> assumed to be *UNKNOWN*.
> Eg, if you miss an update at time t=1 having done one at time t=0, does
> the value become unknown at time t=2 or *after* time t=2. The difference
> is that if you miss just one update, then in the former condition, when
> you come to do the update at time t=2, the data from time t=0 to time
> t=2 will be marked as unknown; but if it's the latter then the data
> wouldn't become unknown unless you also miss an update at time t=2.
> So firstly I would be checking to see that you are reliably doing an
> update every second and not creating a few unknown values. You might
> consider increasing the heartbeat value.
> You have specified an xff value of 0.5, so you would regard a
> consolidation as unknown if 50% of the source values are unknown. Since
> missing one update could be marking 2 seconds worth (ie 2 primary steps)
> as unknown, then missing an average of one update every 4 seconds would
> result in missing consolidated data.
> rrd-users mailing list
> rrd-users at lists.oetiker.ch
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