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check_mrtgtraf.pl producing wrong results

Posted: Wed May 14, 2014 3:32 pm
by gfsatech
Team, I have an issue with the check_mrtgtraf.pl plugin.

I have set it up correctly to monitor bandwidth on the ports on our DELL 8132F switches.

- I have conducted a number of tests in our lab, where we are sending data at a rate of 4-5Gbps from the test machines via the switches. Unfortunately the results that the plugin produces are way off.
- I have even lowered the thresholds to their lowest possible to no avail - we are not getting the required results, and the required alerts.
We need to be able to obtain results when monitoring the switches with this plugin.

This is what I have as a sample in my commands.cfg file:

$USER1$/check_mrtgtraf.pl -F MAX -L /srv/www/htdocs/mrtg/<hostname>/<hostname>_1.log -w 939524096,1006632960 -c 1073741824,1140850688 -u gigabytes

Any suggestions?

Also is there any way I could get a copy of this plugin that handles bits instead of bytes?

Thanks

GFSATech

Re: check_mrtgtraf.pl producing wrong results

Posted: Wed May 14, 2014 4:03 pm
by sreinhardt
Do you know if mrtg is pulling in high counters instead of the standard ones for that device? As for doing bits instead of bytes, you are certainly welcome to modify it to your hearts content. As for which counters it is presently using, posting your mrtg.cfg would go a long ways if possible.

Re: check_mrtgtraf.pl producing wrong results

Posted: Fri May 23, 2014 11:57 am
by gfsatech
Thanks for the tip. I made the correct changes to the mrtg.cfg file - I had forgotten that mrtg does not support high counters for SNMP v1. I have run cfgmaker with the --snmp-options=:::::2 and this partially resolves the problem.

I am monitoring the traffic on 10GBit/s interfaces, however the results from check_mrtgtraf.pl indicate that I am getting a maximum read of 4507.77172851562 Mbyte/s (35.21094Gbits/s).

How is this even possible? Am I missing something here?

Thanks

GFSATech

Re: check_mrtgtraf.pl producing wrong results

Posted: Fri May 23, 2014 2:50 pm
by sreinhardt
If that 4507 was actually megabits, as I believe the counters outputs normally, that seems to calculate to ~.55 gigabytes per second or ~4.4 gigabits, which seems pretty reasonable for your connection, no? Without seeing the labels it's providing, its a bit hard for me to be sure, but it really sounds like it's mislabeling the counter.