[rrd-users] More observations and questions on COUNTER

Simon Hobson linux at thehobsons.co.uk
Sat Oct 23 17:42:53 CEST 2010

Philip Peake wrote:
>Simon, the script forces log data on 30 second boundaries, I use
>calculated times, not "now".
>This includes the NaN value when a data source disappears, and for the
>zero values entered into it every 30 seconds until the source comes back

OK, that rules out a conflict between updates and reset. The bit 
about zeros while the data source is away is new - you didn't mention 

>I have dumped the DB values, and see exactly what I expect

With all due respect - yu apparently aren't seeing what you expect, 
hence the query !

>  - increasing
>values, a NaN (well, I actually got two Nans), then a string of zeros
>followed by a HUGE number (rrd thinks a counter rollover occurred, but
>only when it sees a non-zero data value ????)  followed by data source

What value does your source have when it comes back online ?

I'd still suggest modifying your script(s) to log the update values 
to a text file - it will help enormously if you can provide a set of 
update statements that replicates the problem. Without that we are 
guessing, and you've already "changed the story" as I was assuming 
your were immediately storing real values after the reset (and 
wondering why the zeros before the spike).

Simon Hobson

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