2.6. Performance data

Performance data is defined by Nagios as “everything after the | of the plugin output” - please refer to Nagios documentation for information on capturing this data to logfiles. However, it is the responsibility of the plugin writer to ensure the performance data is in a “Nagios plugins” format. This is the expected format:

'label'=value[UOM];[warn];[crit];[min];[max]

Notes:

1. space separated list of label/value pairs
2. label can contain any characters
3. the single quotes for the label are optional. Required if spaces, = or ' are in the label
4. label length is arbitrary, but ideally the first 19 characters are unique (due to a limitation in RRD). Be aware of a limitation in the amount of data that NRPE returns to Nagios
5. to specify a quote character, use two single quotes
6. warn, crit, min/ or max/ may be null (for example, if the threshold is not defined or min and max do not apply). Trailing unfilled semicolons can be dropped
7. min and max are not required if UOM=%
8. value, min and max in class [-0-9.]. Must all be the same UOM
9. warn and crit are in the range format (see Section 2.5). Must be the same UOM
10. UOM (unit of measurement) is one of:
    - no unit specified - assume a number (int or float) of things (eg, users, processes, load averages)
    - s - seconds (also us, ms)
    - % - percentage
    - B - bytes (also KB, MB, TB, GB?)
    - c - a continous counter (such as bytes transmitted on an interface)

It is up to third party programs to convert the Nagios plugins performance data into graphs.

Origin: http://nagiosplug.sourceforge.net/developer-guidelines.html#AEN201