[rrd-users] How to find first valid dp in rrd - repost - where arethe experts?
linux at thehobsons.co.uk
Wed Nov 19 21:29:37 CET 2008
Just tossing an idea up in the air - it either flies or gets shot
down ! Bear with me, I'm off with flu at the moment so not thinking
Could you do a cdef along the lines of :
t=if (prev(t) is unknown AND d is not unknown) then t=time(d) else t=unknown.
This should, if I'm switched on enough, work through the data, and
set t to the timestamp of the first sample where the data is unknown.
For the initial data both prev(t) and d will be unknown and so t will
stay as unknown. Once the data is known, then prev(t) will cease to
be unknown and no further updates will happen.
That's assuming the functions required are available - I'll leave
someone else to work that out.
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