[rrd-users] Empty sections in AREA on graph, but values in database

Simon Hobson simon at thehobsons.co.uk
Thu Aug 28 11:23:16 CEST 2014


Out of interest, what happens if you simply add a cdef for stufe*100 (CDEF:stufe2=stufe,100,*) and plot a line for that ? I'd expect to see an almost straight line at 100, 200, or 300. Remove the plot commands for the other stuff and the autoscaling should show (say) 99 to 101 or something like that which would accentuate any "wobble".

My guess is that internal maths and rounding means that you don't get exactly 1, 2, 3 - could be 0.999999 or 1.000001 for example.

I'd be tempted to re-write the code like this :
CDEF:stufe0_flag=stufe,0.5,LT,INF,UNKN,IF
CDEF:stufe1_flag=stufe,0.5,GE,INF,UNKN,IF
CDEF:stufe2_flag=stufe,1.5,GE,INF,UNKN,IF
CDEF:stufe3_flag=stufe,2.5,GE,INF,UNKN,IF

AREA:stufe0_flag#7c6767:Stufe 0 AUS \\t
AREA:stufe1_flag#98FB98:Stufe 1 \\t
AREA:stufe2_flag#fafa78:Stufe 2 \\t
AREA:stufe3_flag#fd6969:Stufe 3 \\t

This would also mean that your graph would work after consolidation of data. Eg, at present, if you graph over (say) a week instead of a day, then there will be periods where the values is changing between (say) 1 & 2 and the result will be 1.something for that consolidated period. Using equality comparisons, these values won't math anything, but using comparative statements, it'll show as 1 if the consolidated value is less than 1.5 and 2 if it's over that.



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