Graph & Thold values do not match

[Joost]

Hi,

My graphs are generated based on a 10 second poll-interval & my RRA settings are set to not average any data, even for the longer term graphs (yes, my RRD files are pretty big

I use the Thold plugin to alert for traffic bursts, but I noticed that the maximum values recorded by the plugin do not always match the data stored in the graphs, even though the same CDEF is used for both the graphs and the individual thresholds.. so in my mind this shouldn't be possible.

The Thold e-mail alert, showing that 986Mbit/s was recorded:



The graph, only showing 889Mbit/s:



RRA settings:



Can someone explain this to me, or point me into some kind of direction on where to look for an answer?

Thanks!
Joost

[gandalf]

First, defining multiple RRAs with steps=1 is insane and a waste of rrd file storage. It has been reported, that it will even fail with latest rrdtool releases.

But I don't suppose that this is the root cause of your current problem. To be honest, I don't know the way THOLD works in current releases. In case it fetches data fed into rrdtool, this may differ (due to consolidation performed by rrdtool) from the value that is stored (and thus displayed). This is an assumption only. Please see cacti.log in verbosity mode to learn, which data is fed into rrdtool, then (this may produce a HUGE amount of logging data!)
R.