A state is the evaluated from the conditions defined in a check on the result of a probe. It can have 4 different values:
Unknown: when the state can't be determined, either because there's no value, or because the conditions could not be evaluated;
OK: when the result is considered as normal;
Warning: when the result is considered as worth attention;
Critical: when the result shows an issue that needs a reaction;
Missing Data: when the server has not received any results from the agent for too long.
To determine in which state the result of probe is, you can choose between 3 different algorithms.
The value of one metric is compared to a fixed reference (e.g. free memory is above 1GB).
The trend of the last X values of the metric is compared to a fixed reference (e.g. the rate of change of HTTP/500 errors over the last 25 occurences is below 2).
The value of one metric is compared to the value of the same metric taken Y seconds ago (e.g. the count of successful checkouts compared to the same count 24 hours ago).
Each algorithm can use any number of conditions, bound together with a global logical operator
OR (meaning respectively all conditions should be true or any condition should be true).
Here is the lists of the supported comparison operators.
Less than (
<) Less than or equal (
≤) Equal (
=) Not equal (
≠) Greater than or equal (
≥) Greater than (
=) Not equal (
≠) Match (regular expression
match) Find (regular expression