[mrtg] Threshold process

[Forthofer Russ]

I am just starting to look at using the threshold process within MRTG.    I set up a sample instance today and ran into a question on the "unbroken" messaging.   In this case, I am monitoring CPU.   The threshold is set to 23.  I have not set the "ThreshHyst" parameter, so I believe this should default to 10%.

 I received a message indicating CPU reached 26.79.   That is as expected.  The next message I received was an "unbroken" message, indicating that the CPU was now at 22.13333333.    I was surprised to see this, as I thought I would not get an unbroken message until CPU was at or below 21.7 (Threshold - 10% of Threshold or 23 - 2.3 = 21.7).

Is my math wrong? Or am I misunderstanding when the unbroken message is supposed to be sent?   Did I misread the default value of ThreshHyst?

The only way I can see that this might be expected is if the ".1" default is applied directly to the threshold, in which case I would get an unbroken notice whenever CPU dropped below 22.9.   But if that's the case, is there a difference in the way this will be applied to, for example, the amount of traffic flowing on a 1G link?

Or is there actually NO default, and so I really need to specify ThreshHyst in all instances?

Thanks for any help in clearing up my confusion!

Russ





The information contained in this e-mail and any accompanying documents is intended for the sole use of the recipient to whom it is addressed, and may contain information that is privileged, confidential, and prohibited from disclosure under applicable law. If you are not the intended recipient, or authorized to receive this on behalf of the recipient, you are hereby notified that any review, use, disclosure, copying, or distribution is prohibited. If you are not the intended recipient(s), please contact the sender by e-mail and destroy all copies of the original message. Thank you.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.oetiker.ch/pipermail/mrtg/attachments/20100323/4c46df74/attachment.htm