Hi Alex, Thanks for your answer.
--- On Mon, 2/18/13, Alex van den Bogaerdt <[email protected]> wrote: > For example: if you are using 1200 of those 5-minute > samples, and are > graphing 600 pixels wide, RRDtool has no choice but to > consolidate 2 samples > into 1, 600 times. Things become more complicated if you > have start and end > times not on a logical boundary, or if (end-start)/300 is > not a whole > multiple of horiz_pixels, and so on. Ah, i see, i did not think about that but it sounds logical. So i guess my first take at troubleshooting should be to make the width of the graph >= the number of samples to rule out the effect of consolidation. Which consolidation fuction is used for this operation ? If it the one i defined at the RRA ? > Dividing by _almost_zero_ does not produce NaN, it produces > a very high > number. That is what you encountered. So this supports my > hunch; you are not > looking at zero, you are looking at 1e-10, or you are > looking at > {zero+something}/2. Or maybe {zero*3+something}/4, and so > on. This is indeed something i was looking at, but i couldn't find such numbers in the RRA, but your theory sounds in line with the result. Thanks. > Don't get me wrong, there is always the possibility of a > bug, but that would > not be my first thing to investigate if I would tackle this > problem. I'm not saying this is a bug, i'm using the same setup to calculate an average packet size on network interfaces and there it works as expected. So a but would not be likely. > For some it's a nice excercise to dive into this and analyse > the situation. > For others it's a wast of time, and they should hire someone > to do the job. > You know best in which category you fit best. In my case it's just a personal experiment so i'm happy wasting a lot of time on it and learning something along the way :-) Best regards, Wesley _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
