Problem with rendering correctly the y-axis scale

[klmpencran]

Hi,

I'm trying to understand the Cacti's philosophy, as I'm trying to graph the performance of my callcenter's PATTON VOIP gateways.

These gateways can be polled with SNMP and I'm gathering informations about current connected calls and total amount of accumulated calls within a 5 mn period.

My problem is that I don't understand the numbers and the units generated by RRDTOOL for the amount of accumulated calls. Typically :
- I set up a data template, that collects via SNMP (Get SNMP data) the amount of accumulated calls. The data source type is a counter. Name of the data template : 'accumulated'.
- I set up a graph template, into which i selected the data template 'accumulated'. I select LINE1 as Graph item Type, AVERAGE as consolidation function.

If I test a simple snmpget every 5 mn, polling my gateway, i have this :

Code: Select all

09:14 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893428
09:19 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893603
09:24 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893772
09:29 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893952
09:34 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894123
09:39 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894273
09:44 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894418
09:49 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894577
09:54 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894734
09:59 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1894868
10:04 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895013
10:09 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895152
10:14 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895284
10:19 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895422
10:24 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895571
10:29 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895726
10:34 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1895910

If I export the data from the correspondant graph, I have this :

Code: Select all

"2013-11-29 09:15:00","4.9045426357e-01"
"2013-11-29 09:20:00","5.8602222222e-01"
"2013-11-29 09:25:00","5.6680000000e-01"
"2013-11-29 09:30:00","5.9512671869e-01"
"2013-11-29 09:35:00","5.7813057182e-01"
"2013-11-29 09:40:00","4.9389826504e-01"
"2013-11-29 09:45:00","4.7836135266e-01"
"2013-11-29 09:50:00","5.2807260821e-01"
"2013-11-29 09:55:00","5.2336603913e-01"
"2013-11-29 10:00:00","4.5048888889e-01"
"2013-11-29 10:05:00","4.7980000000e-01"
"2013-11-29 10:10:00","4.6498372352e-01"
"2013-11-29 10:15:00","4.4524839165e-01"
"2013-11-29 10:20:00","4.5327899594e-01"
"2013-11-29 10:25:00","5.0799435154e-01"
"2013-11-29 10:30:00","5.0499464809e-01"
"2013-11-29 10:35:00","6.1592211148e-01"

Why do I have these data in my graph, that don't seem to be in correspondance with what my gateway answers to the snmpget command ?

You will find the debugging command of the generation of the graph :

Code: Select all

RRDTool Command:
/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title='PATTON CVR JUNON - Appels cumules' \
--base=1000 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit=0 \
--units-exponent='1' \
--vertical-label='Nb d'\''appels' \
--slope-mode \
--font TITLE:12: \
--font AXIS:8: \
--font LEGEND:10: \
--font UNIT:8: \
DEF:a="/var/lib/cacti/rra/patton_cvr_junon_accumulated_49.rrd":accumulated:AVERAGE \
LINE1:a#8D00BAFF:"" 
RRDTool Says:
OK

And her is the debug command of the data source

Code: Select all

Data Source Debug
/usr/bin/rrdtool create \
/var/lib/cacti/rra/patton_cvr_junon_accumulated_49.rrd \
--step 300  \
DS:accumulated:COUNTER:600:0:300 \
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 \

Thanks in advance for your help.

[gandalf]

- I set up a data template, that collects via SNMP (Get SNMP data) the amount of accumulated calls. The data source type is a counter. Name of the data template : 'accumulated'.
- I set up a graph template, into which i selected the data template 'accumulated'. I select LINE1 as Graph item Type, AVERAGE as consolidation function.

If I test a simple snmpget every 5 mn, polling my gateway, i have this :

Code: Select all

09:14 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893428
09:19 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893603
09:24 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893772
09:29 : SNMPv2-SMI::enterprises.1768.100.70.40.2.1.4.2 = Counter32: 1893952

If I export the data from the correspondant graph, I have this :

Code: Select all

"2013-11-29 09:15:00","4.9045426357e-01"
"2013-11-29 09:20:00","5.8602222222e-01"
"2013-11-29 09:25:00","5.6680000000e-01"
"2013-11-29 09:30:00","5.9512671869e-01"
"2013-11-29 09:35:00","5.7813057182e-01"

You've used a COUNTER, correct. So each rrd value represents the difference of two consecutive measurements. But it is a rate, so it is interpreted as a "per second" value. If you want to have a "per 5 min value", please use a CDEF to multiply by 300
R.