Final test: Observability: metrics, alerts, logs

Read the output

You added a rule with a typo in its expression and reread the configuration. Which rules does Prometheus use now?

$ sudo systemctl reload prometheus; echo $?
0
$ sudo journalctl -u prometheus -n 3 -o cat | grep -o 'previous rule set restored'
previous rule set restored

• A The new ones, except the rule with the typo.
• B The previous ones, loaded before the reread.
• C None — Prometheus dropped all rules until the fix.