[rrd-users] Counter resetting causing huge spikes

Piers Kittel mailing at biased.org
Sun Sep 9 10:32:25 CEST 2007

Hello all,

I'm currently measuring my electricity usage using an counter - each  
time the meter flashes 1/800kWh, the counter value is put in the  
database.  As it's a 32 bit integer, I've set the known limits to be  
0 - 4,294,967,297 in the database.  Thing is, if the counter resets  
to zero due to the sensor recording program restarting, the database  
assumes I've gone all the way to 4,294,967,296 and then back again,  
causing a huge spike showing I've used 228GW in 1 min.  Now all of my  
graphs all the way up to the yearly graph shows that spike, and it's  
likely I'm not able to see anything until a year later - is there a  
way to prevent this?  Should I not put in a known upper limit, but  
rather, putting in an "U" - will this fix it?  Am I able to remove  
the errant data out of the database, or will I need to re-create the  

Thanks for your time in advance!

Regards - Piers

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