Rules judge and what a chart draws. Anything that is not a number is a fact. - facts are short strings worth showing beside them (os, php, release), kept with the latest reading only. - details are whatever a page needs to explain the reading (the disks, the top processes, the last log lines), kept with the latest reading only. - counters are cumulative numbers (requests served since boot, bytes read in a log): the hub turns two consecutive ones into a rate (Hub::rates), as a single one means nothing.
- `metrics` are numbers only, named with dots (`disk.root.usedPercent`): they are what the time series keep, what
A reading's status only gets worse while it is built: a probe sets what it saw, [`Rules`](https://mmoframework.fr/fr/documentation/mmo.admin/php/monitoring/Rules.md#rules) raise it, and nothing
lowers it back.
$reading = new Reading('server:ovh1', 'system');
$reading->metric('load.1', 0.42)->fact('os', 'Ubuntu 24.04')->raise(Reading::WARNING, 'swap is used');