Configuring States

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.

Algorithms

To determine in which state the result of probe is, you can choose between 3 different algorithms.

Threshold

The value of one metric is compared to a fixed reference (e.g. free memory is above 1GB).

Trend

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).

History

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).

Conditions

Each algorithm can use any number of conditions, bound together with a global logical operator AND or OR (meaning respectively all conditions should be true or any condition should be true).

Here is the lists of the supported comparison operators.

Numeric comparison

Less than (<) Less than or equal () Equal (=) Not equal () Greater than or equal () Greater than (>)

String comparison

Equal (=) Not equal () Match (regular expression match) Find (regular expression find)