​HowToWritePlugins > fieldnames > critical

{fieldname}.critical

{fieldname}.critical defines low and/or high thresholds that will be used by munin-limits? to send a critical alert to external systems like Nagios if the read value is outside the given range.

Properties

Attribute name	{fieldname}.critical
Value	min:max, min: or :max
Allowed characters	[0-9:]
Spaces allowed	No
Context	Datasource-specific plugin attributes
Required	No
Default value	None

Example

In the example below, munin-limits? will send an alert with "critical" level if the number of pending packages is higher than (or, although improbable, lower than) 0 packages.

# munin-run apt config
graph_title Pending packages
graph no
pending.label pending
pending.critical 0:0
hold.label hold

See also

{fieldname}.warning