[rrd-users] newbie rrd question - probably a very old issue

Tobias Oetiker tobi at oetiker.ch
Sat Sep 1 20:49:26 CEST 2007


Dan,

note that rrdfetch is NOT consolidating anything, it shows you what
is stored in the rrd ... if you want to see what is actually
stored, use rrdtool dump ...

you may also want to read through the mailinglist archives, since
we get someone like you every few months how needs many days of
patient explaining until he understand why rrdtool is designed the
way it is designed and why it works the way it works, and why this
is the right thing todo ... (it has been like this for the last 8
years actually and tousands have used and understood the logic) ...
you will get there ...

cheers
tobi


>
> that's not exactly what I want.
>
> to be honest, I'd be happy if rrd did one simple thing (or two depending on
> your point of view).
>
> I'd recommend the "min" and "max" of the average function be done a bit
> differently.
> for an average graph, the "maximum" (shown at the bottom) should always be
> kept,
> and the "minimum" should always be kept
>
> also the points for those on the graph should always be kept, even if it means
> the verticals in the graph are stretched a bit.
>
> the graph doesnt have to show ever portion of the scale either. by this I mean
> if there are no values between 10 and 40, you dont need to show the portions
> from 11-39 essentially
> as long as the maximum, minimum and average are represented properly
>
> it should be simple enough to keep track of the minimum and maximum over time.
> my logic:
> if you have a spike of 100 one day and that is you maximum, then a week or a
> month or a year later, if that is still your maximum, then it is always your
> maximum, and the spike should be shown
> today it should be the max, tomorrow it should be the max, and until a higher
> value occurs, it should always be the max, same with minimum, if we got a
> zero, that will always be the minimum. and the overall average should be the
> average between those two values.
>
> otherwise the data is incorrect and quickly becomes meaningless.
> yesterday it spiked to 90, but today it shows the max is only 30, so did it
> spike? not according to the graph it didnt.
>
> and I still dont understand why the command line (rrdfetch) is consolidating,
> it has no graphing limitations
>
> I don't know a better way to do it.
> Dan.
> > From: Jason Fesler <jfesler at gigo.com>
> > To: Dan Gahlinger <dgahling at hotmail.com>
> > CC: tobi at oetiker.ch, rrd-users at lists.oetiker.ch
> > Subject: Re: [rrd-users] newbie rrd question - probably a very old issue
> > Date: Sat, 1 Sep 2007 10:09:32 -0700 (PDT)
> >
> > Based on a side conversation with Dan, this is what I'm understanding:
> >
> > RRD will graph exactly one consolidated point in time, if there are more
> > points than pixels on the X axis.  Dan wants *all* value points represented,
> > not consolidated.  RRD has no option to do that.
> >
> > I'm thinking that *maybe* it can be faked, with some stacked graphs or
> > something, *if* MIN and MAX were also included in the rrd file; do a fill
> > between min and max.
> >
> > But it isn't going to happen with a single graph statement, and I'm having
> > problems figuring out how to sanely show min/average/max if desired. :-)
> >
>
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>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten
http://it.oetiker.ch tobi at oetiker.ch ++41 62 213 9902



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