Negative values in Triggers

[paultorben]

Hi,

I tried searching for an answer to this but all I found was a posting from a couple of years ago:

http://www.zabbix.com/forum/showthread.php?t=5680

where Alexei says that negative values in triggers aren't supported yet - Alexei are they supported in any current release / alpha?

I've trying to monitor the voltage output from sensors, and the -12V and -5V items (from a power supply monitor) can't be monitored by a trigger in 1.1.7

({Games2:sensor.voltage.n12v.last(0)}>(-10.9))|({Games2:sensor.voltage.n12v.last(0)}<(-13.1))

Incorrect trigger expression '(0>(-10.9))|(0<(-13.1))'

Any thoughts / suggestions welcome.


Thanks,

Torben

[paultorben]

* bump *

seriously - no way to monitor negative values??

note - i'm using Zabbix 1.1.7 and I've been very pleased with Zabbix over the last 2 years ...

[paultorben]

[solved but ugly]

I figured out a hack to make this work:

Z - ( Z *2 )

so from my original example - taking the first half:

({Games2:sensor.voltage.n12v.last(0)}>(-10.9))

became:

( {Games2:sensor.voltage.n12v.last(0)} ) - ( {Games2:sensor.voltage.n12v.last(0)} * 2) > 10.9

which seems to work fine.

[Alexei]

Nice hack, yet wrong one It should be like this I guess:

( {Games2:sensor.voltage.n12v.last(0)} *2 ) - ({Games2:sensor.voltage.n12v.last(0)}) > 10.9

[paultorben]

Nice hack, yet wrong one It should be like this I guess:

( {Games2:sensor.voltage.n12v.last(0)} *2 ) - ({Games2:sensor.voltage.n12v.last(0)}) > 10.9

Thanks for the reply! Love Zabbix by the way and can't wait to upgrade to 1.4 !

Unfortunately your addition/subtraction with negative numbers is wrong.

example:

say n12v = -12.0

in your solution that would work out like:

( -12.0 * 2 ) - ( -12.0 ) = ( -24 ) + 12 = -12

Still a negative number which Zabbix can't evaluate (in a trigger as noted above).


Mine works out like this:

( -12 ) - ( -12 * 2 ) = ( -12 ) - ( -24 ) = ( -12 ) + 24 = 12

the end result is a positive number, which Zabbix can then evaluate

so,

( {Games2:sensor.voltage.n12v.last(0)} ) - ( {Games2:sensor.voltage.n12v.last(0)} * 2) > 10.9

is correct for converting a negative value result into a positive number - without being able to use math function like abs() - hey if you had abs() (which returns the absolute value of a number - i.e. without a negative sign) where you also have the average and mix /max functions for triggers then this problem would disappear:

abs( {Games2:sensor.voltage.n12v.last(0)} ) > 10.9

any chance it would be easy to add in with those min/max/etc. trigger functions?