Monitoring numeric non-integer SNMP values with IPCheck Server Monitor

If you try to monitor a numeric non-integer value (e.g. fractional values) using the SNMP sensor of IPCheck Server Monitor you will only see zero values. The reason is that the standard SNMP sensors of IPCheck Server Monitor only support integer values.

By using a Custom Script Sensor that actually performs some calculations this limitation can be overcome. The following script shows how to do this:

' Script to read non-integer OIDs and multiply them up for IPCheck
' data1 == OID (1.3.... etc)
' data2 == warning threshold
' data3 == error threshold
'initialize sensor's result to status of "error"
sensor.resultvalue=0
'For Version 5.2 or earlier use: sensor.resultvalue=0
sensor.status=srError
sensor.errortype=etNone
'get the snmp values (as string)
result=snmpget("public",data1)
'result="ERROR"
'check for errors (always begins with the word "ERROR")
if pos("ERROR",result)=1 then
  sensor.errorstring=result
  sensor.errortype=etprotocol
else
  sensor.status=srok
  mynumber=round (result)
  if mynumber > data3 then
    sensor.status=srError
  else
    if mynumber > data2 then
        sensor.status=srWarning
    end if
  end if
  mynumber=strtoint(mynumber)
  sensor.resultvalue=mynumber
end if

The most important line of code is marked green in the code. This line converts the float value into an integer value. If may also choose to multiply the value with e.g. 1000 if you also need to look at changes below the integer resolution.

When creating the new sensor in IPCheck's user interface set the three data fields as follows:

• data1 = OID of the value you want to monitor
• data2 = your warning threshold
• data3 = your error threshold

Please see the links in the Related Articles Section below for more information. The basics of Custom Script sensors are explained in the manual of IPCheck Server Monitor.

Thanks to Stuart Hall for sharing this tip.