Logarithmic Auto Scaling y-axis

[lobbin]

I have created a logarithmic graph, but the y-axis doesn't display values that good.

It display 1e+00 and the next value is 1e+01. Any ideas what I should change to have the axis print the actual value?

[cuicui]

Up

Yes, i know, this post was opened more than two years ago, but i also use semi-log scale for my network graphs and more human readable values would be nice...

Any idea?

All the best,

[BSOD2600]

What would be better to display? This is purely a rrdtool issue anyways so the topic belongs on the rrdtool mailing list...

[cuicui]

What would be better to display?

The Y axis values.

[BSOD2600]

Those values are being displayed though, logarithmically.

You got a sample of what you're talking about?

[cuicui]

Instead of having the values displayed in exponential form (1e+07), i'd like to have them in kb/Mb, units. Same as MRTG when you do some semi-log graphs.

[BSOD2600]

Alright... so once again this is a rrdtool issue. Post on their mailing list.

[cuicui]

Alright... so once again this is a rrdtool issue. Post on their mailing list.

I will, but maybe this could be automatically managed in the futur versions of Cacti: displaying human readable Y values when switching from linear to semi-log scale.

As far as Cacti have a semi-log option, we shouldn't have to dig to have human readable Y axis values.

All the best,

[gandalf]

Please post the pure rrdtool statement (start with the one seen in Graph Management) you want cacti to generate. I'll have a look at it
Reinhard

[cuicui]

You're very kind.

Code: Select all

RRDTool Command:

/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title="toutatis - Traffic - eth0" \
--rigid \
--base=1000 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit=1000 \
--logarithmic \
--vertical-label="bits per second" \
--slope-mode \
DEF:a="/opt/apache-2.0.58/htdocs/cacti/rra/toutatis_test_traffic_in_103.rrd":traffic_in:AVERAGE \
DEF:b="/opt/apache-2.0.58/htdocs/cacti/rra/toutatis_test_traffic_in_103.rrd":traffic_out:AVERAGE \
CDEF:cdefa=a,8,* \
CDEF:cdefe=b,8,* \
AREA:cdefa#00CF00:"Inbound"  \
GPRINT:cdefa:LAST:" Current\:%8.2lf %s"  \
GPRINT:cdefa:AVERAGE:"Average\:%8.2lf %s"  \
GPRINT:cdefa:MAX:"Maximum\:%8.2lf %s\n"  \
LINE1:cdefe#002A97:"Outbound"  \
GPRINT:cdefe:LAST:"Current\:%8.2lf %s"  \
GPRINT:cdefe:AVERAGE:"Average\:%8.2lf %s"  \
GPRINT:cdefe:MAX:"Maximum\:%8.2lf %s" 

Code: Select all

Data Source Debug

/usr/bin/rrdtool create \
/opt/apache-2.0.58/htdocs/cacti/rra/toutatis_test_traffic_in_103.rrd \
--step 300  \
DS:traffic_in:COUNTER:600:0:100000000 \
DS:traffic_out:COUNTER:600:0:100000000 \
RRA:AVERAGE:0.5:1:600 \
RRA:AVERAGE:0.5:6:700 \
RRA:AVERAGE:0.5:24:775 \
RRA:AVERAGE:0.5:288:797 \
RRA:MAX:0.5:1:600 \
RRA:MAX:0.5:6:700 \
RRA:MAX:0.5:24:775 \
RRA:MAX:0.5:288:797 \

[gandalf]

As far as Cacti have a semi-log option, we shouldn't have to dig to have human readable Y axis values.

Do you refer to MRTGs logscale option? Please post a screenshot of that MRTG graph you're aiming at along with the MRTG parms set for this target
Reinhard

[cuicui]

Here's the graph.


Options used to have this on MRTG are:

Code: Select all

Options[_]: growright, bits, logscale

[gandalf]

The "logscale" option is not valid for rrdtool. From man rrdgraph:

Code: Select all

[-X│--units-exponent value]

               This sets the 10**exponent scaling of the y-axis values. Normally, values will be scaled to the appropriate
               units (k, M, etc.).  However, you may wish to display units always in k (Kilo, 10e3) even if the data is in
               the M (Mega, 10e6) range, for instance. Value should be an integer which is a multiple of 3 between -18 and
               18 inclusively.  It is the exponent on the units you wish to use. For example, use 3 to display the y-axis
               values in k (Kilo, 10e3, thousands), use -6 to display the y-axis values in u (Micro, 10e-6, millionths).
               Use a value of 0 to prevent any scaling of the y-axis values.

               This option is very effective at confusing the heck out of the default rrdtool autoscaler and grid painter.
               If rrdtool detects that it is not successful in labeling the graph under the given circumstances, it will
               switch to the more robust --alt-y-grid mode.

This is not exactly what you requested, but the only option I see at the moment. But you may post your request to the rrdtool mailing list for adding a new option ...
Reinhard

[cuicui]

The "logscale" option is not valid for rrdtool. From man rrdgraph:

Code: Select all

[-X│--units-exponent value]
[...]
               This option is very effective at confusing the heck out of the default rrdtool autoscaler and grid painter.
               If rrdtool detects that it is not successful in labeling the graph under the given circumstances, it will
               switch to the more robust --alt-y-grid mode.

This is not exactly what you requested, but the only option I see at the moment. But you may post your request to the rrdtool mailing list for adding a new option ...

Ok, thanks for your help and your patience

All the best,

[MaF]

I have created a logarithmic graph, but the y-axis doesn't display values that good.

It display 1e+00 and the next value is 1e+01. Any ideas what I should change to have the axis print the actual value?

I also had this problem. Then I checked "SI-Units for..." an the values at the y-axis are (for me) ok.


MaF