Re: check_snmp multiplier / divisor

On 08/17/12 03:15, Andreas Ericsson wrote:
> On 08/17/2012 03:41 AM, Eric Schoeller wrote:
>> Hello list,
>>
>> We have a fair number of checks using check_snmp, and it is very common
>> that an INTEGER is reported in 'tenths' or even 'hundredths'. To use
>> check_snmp natively against these OIDs we are forced to set thresholds
>> such as '700' to represent '70.0' Fahrenheit. This isn't too big of a
>> problem except when tired admins get pages about temperatures reaching
>> (what appears to be) 700 degrees Fahrenheit.
>>
>> In such cases we could simply write our own plugins, but there are a lot
>> of these cases. It would be far more desirable to just use check_snmp. I
>> was considering developing and submitting a patch for options such as
>> --multiplier or --divisor ... or even perhaps --mangle where in you
>> could perform a bit of math on any values returned from the SNMP agent.
>> Thresholds would then be applied to the "mangled" value of the OID.
>>
>> Would there be support for such a change if we submitted a patch? Is
>> there a reason why it would be unnecessary?
>>
> I would love such a patch. Sounds like a generally awesome idea. In order
> to sanely implement it, I suggest supporting only simple math that can be
> parsed easily and unambiguously. It's likely to cover 99% of the cases,
> and for the rest, people will have to write their own plugins.
>
> You'd possibly want some "power of 2 to percent" thing though, since a
> lot of snmp-capable devices use all available precision to report
> some available resource, so "--formula=pct(256)" would transform "128"
> into "50".
>
> I'd implement the math part as macros if I were you. That way they'll be
> type-agnostic and work well in a wide range of scenarios.
>

Great, I'm glad you are interested in the idea. We will take a look at 
submitting a patch.

William,

I just deployed your check_snmp_temperature plugin across 19 of our Dell 
servers. Looks really good so far. Looks like this plugin will cover 
about 30% of our needs - the 'formula' option to check_snmp will be 
useful for things other than temperature. Some examples are UPS runtime, 
RAID latency, differential pressure, % valve opening, humidity, voltage, 
amperage, watts ... etc.

One suggestion, and this may sound crazy, but it might be nice to have a 
range implemented for check_snmp_temperature similar to how check_snmp 
handles ranges. Strangely enough, in some cases I would like to know if 
devices get TOO cold !

Thanks,

Eric

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________________
Nagios Plugin Development Mailing List Nagiosplug-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Unsubscribe at https://lists.sourceforge.net/lists/listinfo/nagiosplug-devel
::: Please include plugins version (-v) and OS when reporting any issue. 
::: Messages without supporting info will risk being sent to /dev/null