Hello Steve,
The version I am using was 1.4.7 on ubuntu precise. I've now compiled
the latest stable (1.4.8) but there are no differences between them.
Also I've played around with the order of the commands (putting all the
graph rendering in front/behind etc), but that also does not make a
difference.
Regards,
Marius Karthaus
On 06-09-14 01:54, Steve Shipway wrote:
Looking at the two graphs, they cover the same data width but the
second is 2x the pixel width, and so has less on-the-fly consolidation
before graphing. From this, as I would expect, the peaks in the first
graph are averaged out more, and so show up as lower (around 50M).The
second graph shows the peaks narrower but higher (around 70M) due to
their having less averaging applied. So far, so good and as expected.
However, the percentile calculation (as I understand RRDTool's data
handling) should not be affected by the graph-time consolidation, and
should apply to the extracted data set, which we have forced to the
same resolution in both graphs. However, the lower value printed
would seem to indicate that this is not the case, and the graph
consolidation is taking place /before/ VDEF calculation. This only
shows up because the data are extremely spiky in pattern and have a
fair amount of consolidation being applied. If this is the case it
would seem to be contrary to the behaviour implied by the
documentation (that sounds like a long way of saying "i think its a
bug' :)
I don't believe that you have told us which version of RRDtool you are
using? If you're not on a recent version, it might be worth trying an
upgrade., just in case this is related to a recently-fixed bug.
Steve
*Steve Shipway*
University of Auckland ITS
/UNIX Systems Design Lead/
[email protected] <mailto:[email protected]>
Ph: +64 9 373 7599 ext 86487
//
_______________________________________________
rrd-users mailing list
[email protected]
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
