Cache and freshness

It can be harmful to the server to run all checks on each HTTP endpoint call, so the application is running them periodically every X seconds specified by –refresh-time switch or REFRESH_TIME environment variable (in docker)

Refresh time

If you use an official docker image, then you can set an environment variable.

Example: check once a day (good for domains whois check).

REFRESH_TIME=86400

From CLI you can set –refresh-time=86400

Wait time

Some checks could call external APIs, those can have limits. A good example is a domain-expiration check which is using whois. Set –wait=60 to for example wait 60 seconds before each check - where check is a single entry on the list of checks.

Customizing check freshness time per check

Beside the global setting of refresh time there could be a per-check setting called “results_cache_time”.

Example of caching the check result for at least 300 seconds

{
    "type": "swap-usage-max-percent",
    "results_cache_time": "300",
    "input": {
        "max_allowed_percentage": 0
    }
}