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rrdtool

RRDTool database definition and plotting the data -I need a second opinion

Here is what I am trying to achieve: I read my data once a day (the exact time of the day is not very important). I want to archive the values for this DS for two years back. I need to be able to look back for 2 years and I need the value for every day and I also need to see the weekly average If I miss a reading for two consecutive days the data should be declared unknown

Here is what I am using for this:

rrdtool create Carsforsale.rrd --start 20130217 --step 86400 ^ 
DS:MidsizeCars:GAUGE:172800:U:U ^ 
DS:FullSizeCars:GAUGE:172800:U:U ^ 
RRA:AVERAGE:0:7:104^ 
RRA:LAST:0:7:1:720

I updated the above database with 

rrdtool update Carsforsale.rrd 1361203200:554:791
rrdtool update Carsforsale.rrd 1361289600:556:795

The updated correspond to yesterday and the day before yesterday (18, 19 Feb)

I tried to plot the graphs for the above using this

rrdtool graph "Inventory.png" \
--start "20130217" \
--imgformat PNG --width 850 --height 400 \
DEF:MidsizeCars=Carsforsale.rrd:MidsizeCars:AVERAGE \
DEF:FullSizeCars=Carsforsale.rrd:FullSizeCars:AVERAGE \
AREA:MidsizeCars#0000FF:"MidsizeCars" \
AREA:FullSizeCars#FF004D:"FullSizeCars:STACK"'

And now here are the my questions:

  1. are the step and the heart beat defined correctly for what I wantto do ?
  2. Why are my graphs empty ?
  3. Looking into the database with the freeware utility called RRD Editor I could see that the last values are stored in the MidSizeCars and FullSizecars but the only DS that contains a history of what has been loaded into the database is the archiving function LAST Am I supposed to plot LAST or Average to see the current values ?

Thanks C

Solution

  • since you want to keep the data for two years at 1 day resolution, you have to setup an appropriate RRA for this purpose ... since this will only be about 730 values, I would not bother with setting up an extra consolidated RRA for the week. this will get calculated on the fly ...