[rrd-users] Re: Next question: x,UN,0,IF funky output

[Tobias Oetiker]

Yesterday you sent me mail regarding [rrd-users] Next question:  x,UN,0,IF...:

*> Since I stack lots of data on top of each other, I use the following
*> CDEF to ensure that my data is either defined or zero:
*> 
*> 	CDEF:xdata=data,UN,0,data,IF,8,*
*> 
*> The problem with this is that my graphs turn out with the last point
*> always at zero.  This makes it look like my traffic is always diving
*> towards zero!
*> 
*> My hypothesis is that the .rrd archive returns an undefined value for
*> any time since the last update.  This makes sense in a pedantic sort
*> of way, but when I draw the graph and see the lines diving toward zero
*> at the far right, it doesn't make sense at all.
*> 
*> Is there a way to have it both ways?  I mean, have my graphs *not*
*> dive toward zero, but have undefined data interpreted as zero for
*> stacking purposes?

yes you could use the TIME and the NOW variable in your CDEF to have a time
dependant behavior ... 

on the developers list there has just been a discussion on the stacking of
*UNKNOWN* and it has been determined that stacking unknown should be treated
as if not stacking anything ... so you will not have to turn unknown into 0
anymore starting from 1.0.4 ...

cheers
tobi

*> Dave
*> 
*> --
*> * To unsubscribe from the rrd-users mailing list, send a message with the
*>   subject: unsubscribe to rrd-users-request at list.ee.ethz.ch
*> 
*> 

-- 
 ______    __   _
/_  __/_  / /  (_) Oetiker, Timelord & SysMgr @ EE-Dept ETH-Zurich
 / // _ \/ _ \/ / TEL: +41(0)1-6325286  FAX:...1517  ICQ: 10419518 
/_/ \.__/_.__/_/ oetiker at ee.ethz.ch http://ee-staff.ethz.ch/~oetiker

--
* To unsubscribe from the rrd-users mailing list, send a message with the
  subject: unsubscribe to rrd-users-request at list.ee.ethz.ch