[hobbit] Re: Help - NCV graph issue

[Ralph Mitchell]

On 6/29/07, White, Bruce <bewhite at fellowes.com> wrote:
> Hi all,
>
> I have yet a different problem with an NCV graph.
>
> I have a script which monitors are UPS.  In the script it captures the
> current load. I have set-up the hobbitserver.cfg file and hobbitgraph.cfg
> files based on the examples and it is storing the data and producing the
> graph, but the numbers don't match.  When I do an rrdtool dump I see the
> current data point is ok (like 29% and I see that 29 is the current
> datapoint).  When it graphs it, it shows it as 8.   I have tried playing
> with the data types and that doesn't help.
>
> Any ideas?

RRD expects the data at rigidly specified intervals.  Any datum
entered slightly off the expected interval is "extrapolated" to fit
the correct interval.  If you manage to get it *really* close to the
correct time, then it goes in almost untouched.  I'm guessing you
could be hitting somewhere in the middle of the interval, for it to be
so wildly out

Or I'm completely wrong...  :)  It's worth looking into, though,
because the extrapolation does happen.

Ralph Mitchell