On Tue, Feb 24, 2004 at 07:04:04PM -0800, Sandor W. Sklar wrote: > >> Under what conditions would a graph containing no data be of value? > > > > rrdtool is built to handle missing data. > > whether it is before, after or during the time spanned by your rra's. > > It just displays it as being NaN, which in my opinion is much better > > than to generate errors and such. > > I'd agree with you, if there was one valid data point within the range. > I'd think though, that if there were zero data points in the range > requested, an error would be in order. > > It doesn't matter, though, since there is nothing I can do to change it > without modifying the code.
If you want to know when "NaN" occurs, use a CDEF to transform these into INF and display in bright red: CDEF:unknown=mydata,UN,IF,INF,UNKN,IF AREA:unknown#F00 > >> if the timestamp of the last update of the rrd is > >> earlier then one week ago, then I know that I don't have the > >> data that I want. > > > > Ah, I assumed you kept on updating the rrd with nans and you wanted to > > find > > the last time a valid number was entered. > > Why would one update an RRD with NaNs intentionally? - signal the viewer the connection with a device was lost - signal the viewer the device reported it could not deliver the requested data - signal RRDtool a reboot or other counter reset will occur maybe more. Alex -- begin sig http://www.googlism.com/index.htm?ism=alex+van+den+bogaerdt&type=1 This message was produced without any <iframe tags -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
