[rrd-users] what to do with data that resets every day

[Simon Hobson]

Joey Rutledge wrote:
>I am trying to setup some graphs on total connections (mail server)
>and am getting data from the application via a web dashboard.  The
>application resets the data for total connections on a daily basis
>back to zero and essentially does a total count of connections for
>each day (COUNTER).  I want to be able to setup some rrd graphs with
>this info but can't figure out the best way to go about this.  Has
>anyone had to work with data like this and if so what how did you
>handle the ever so frequently reseting of the data to zero?
>
>Any help that anyone could provide would be greatly appreciated and if
>this is a RTFM issue please point me in the right direction.

IIRC the DERIVE type will deal with this. While data is increasing it 
acts like a COUNTER type, but if it decreases it assumes a reset or 
counter wrap. I think you'll lose the sample where the counter 
resets, but I suppose you could always add some extra sampling either 
side of the reset to minimise that.