How to add a rate in a graph

[chris35]

Hi,

I am a newbie to cacti, running 0.88a.
I have a RRD with application response times datasources and an 'error' datasource equal to 1 when my application isdown and to 0 when the application is working fine.
I want to display the application availibility rate on my graph (as a comment or gprint) but can't find out how to do that.
Any idea ?

[gandalf]

Well, that will include some CDEF magic at least. You may find resources on the web when searching for "rrdtool" and "availability"; even in this forums you may find solutions posted by users ...
R.