Monitor types

REST Health Check

The Representational State Transfer (REST) health check reads a JSON response and extracts a value with a JSONPath. You enter expressions such as $.status == 'UP' for OK when, Degraded when and Critical when. The path comes from the OK when expression, and the comparison is an exact string match.

Critical is checked first, then Degraded, then OK. If nothing matches, or the path is missing, the check counts as an execution failure.

Without any path, any 2xx reply is Operational. It is Degraded when the reply took more than 80 percent of the timeout.

Text Match

In Response content mode, the body is searched for the Critical, Degraded and OK match values, in that order. Matching is case-insensitive. If none match, the check counts as an execution failure.

In HTTP status code mode, each reply class (2xx, 3xx, 4xx, 5xx) is mapped to a status. The defaults are 2xx and 3xx Operational, 4xx Critical and 5xx Degraded.

DOM Assertion

The page is loaded in headless Chromium and the DOM selector is looked up.

• Element missing: Critical.
• Element present and no match values set: Operational.
• Element present with match values: the text inside it is compared like Text Match.
• If the page redirects to another Uniform Resource Locator (URL), the check counts as an execution failure.

HTTP errors in content mode

For REST Health Check and Text Match in response content mode, the reply code is checked before the body: a 5xx reply is Critical, and a 4xx reply is an execution failure.