Graph template with "No value" zone

[Tulan]

Hello,
an ISP provider give us Cacti graphs for bandwith usage with a cool feature: when Cacti can't access the device a red area is displayed on the graph.

Do you know how to add this feature in a graph template? The Cacti system is very powerfull but a little too complicated sometimes

We are using Cacti 0.8.7e.

[gandalf]

Primarily, you are not asking for a Cacti feature but an RRDTool Feature.
Do you see a wrench next to the graph? Then, please hit it and post the rrdtool garph statement found. Else, please see http://docs.cacti.net/manual:087:6_reference.2_cdef#cdefs to learn how to solve similar approaches. Be prepared for some hard work ahead
R.

[Tulan]

You are right it is a RRDTOOL problem. After reading the RRDTOOL manual, I have discovered the solution is very simple ... after understanding the RPN notation

• Create a new CDEF (called "Unknown Data" for me) with content: CURRENT_DATA_SOURCE,UN,INF,UNKN,IF
  
  
  
  • 1st step: CURRENT_DATA_SOURCE,UN test if the current data value is Unknown. Result is 1 if yes, 0 if not
    After this step the function is 1,INF,UNKN,IF or 0,INF,UNKN,IF
    
  • 2nd step: the IF statement test if the previous result is 1 or 0. If yes it return INF (infinity), UNKN (unknown) if not
    
  
  
• In the graph template, create a new "Graph Template Item" with the datasource in input, type AREA and the new created CDEF as CDEF function. If the result of the CDEF function is INF, the grapher fill the area to maximum, but don't draw anything if the result is UNKN
  

The final RRDTOOL command for the attached graph

[TheWitness]

Pretty cool

[gandalf]

[Tulan]