[HOWTO] Debug NaN's in your graphs

[pbud70]

OK, got it with the excellent help of the folks @ ITPA www.ipta.org.au . Basically the data value that I was putting in had a trailling \r\n. Finding this out was done with…

root@whisk:~# echo “$myvar” | od -a
0000000 0 . 7 8 cr nl
0000006

and:
printf "%f" "$myvar"
: invalid number.78
0.000000

This occurred because it was the last field (column) in the file, so “cut” was grabbing the carriage return as part of the last field.

I fixed it by adding an additional dummy field to the returned sql, so that instead of grabbing the last field in the data set I’m now grabbing the second last field.

So now I get:
echo “$myvar” | od -a
0000000 b nul fs 0 . 7 8 b nul gs nl
0000013

now which works OK and there’s aggregate data appearing in rrds now.

Cheers,

Chris

[Erudes1991]

I cannot follow these steps, they are quite difficult to me, can you guys provide me assistance?

[artvarck]

One of issues I found that was causing "nan" in place of actual data points was McAfee Endpoint Security for Linux (ENS) interfering with rrdtool. White listing spine and rrdtool, and the entire /var/lib/cacti/ directory resolved the issue.

[TheWitness]

McAfee, the company notorious for writing their own virus'. Research George Webb and find out. He worked for John years ago, and his team wrote viruses to keep the software company viable. Lovely how that works. It's like politics.