Graph shows different data usage when viewed 2 months later

[clandagent]

With no custom changes made and not interface changes(both on router and in cacti) bandwidth usage isn't showing the same when viewed later. Original view is spiked, but when viewed ~2 months later it looks blocky and the values are lower. The data is recorded using snmp v2 and 64 bit counters.

Has anyone else ran into this error?
Any help would be appreciated.

[clandagent]

Manually generating the graph with the following code produces the same blocky(bad) graph so I assume cacti is somehow at some point altering the rrd data...

Code: Select all

/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=1183273200 \
--end=1185951540 \
--title="ROUTER(64) Fa1/3 DESCRIPTION_REMOVED" \
--base=1000 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit=0 \
COMMENT:"From 2007/07/01 00\:00\:00 To 2007/07/31 23\:59\:00\c" \
COMMENT:"  \n" \
--vertical-label="bits per second" \
--slope-mode \
--font TITLE:8:/usr/share/rrdtool/fonts/cour.ttf \
DEF:a="/var/www/localhost/htdocs/cacti/rra/ar01_traffic_in_2641.rrd":traffic_in:AVERAGE \
DEF:b="/var/www/localhost/htdocs/cacti/rra/ar01_traffic_in_2641.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\n"  \
COMMENT:"\n"  \
HRULE:2078119.32#FF0000:"95th Percentile"  \
COMMENT:"(2.08 mbit in+out)" 

This is affecting all interfaces on all routers monitored, not just a single interface.

[BSOD2600]

You do realize that rrdtool consolidates data right? read http://docs.cacti.net/node/275

[clandagent]

You do realize that rrdtool consolidates data right? read http://docs.cacti.net/node/275

Doh!

Is there a way to prevent/disable that?!?!

I used a different rrdtool bandwidth monitor(jffnms) in the past and it didn't consolidate the data and change the values, ever.

What I mean is I'd like the bandwidth displayed to always show the same thing and not change when viewed at a later date...

[clandagent]

I guess there is no preventing the consolidation, only preventing when it happens by setting the size of the db file. So is there a way to increase the size of the existing rr files to some much larger size to allow at least a years worth of unconsolidated data? I understand there is no way to recover the already consolidated data.

[gandalf]

It is possible to increase the rrd file. This is as well described in my rrdtool related chapters in the docs linked above. But please read carefully! I suppose, you will not be satisfied by only increasing the rrd file size.
A better approach would be to graph not only AVERAGEs, but MAXIMUM as well. I suppose that will fit better without increasing rrd file size
Reinhard