service/prometheus.md

@@ -1372,7 +1372,15 @@ tests:
     # Set of fixtures for the tests below
     input_series:
       - series: 'node_reboot_required{alias="NetworkHealthNodeRelay",instance="akka.0x90.dk:9100",job="relay",team="network"}'
-        # that's "one" for 60 samples, or 60 minutes
+        # this means "one sample set to the value 60" or, as a Python
+        # list: [1, 1, 1, 1, ..., 1] or [1 for _ in range(60)]
+        #
+        # in general, the notation here is 'a+bxn' which turns into
+        # the list [a, a+b, a+(2*b), ..., a+(n*b)], or as a list
+        # comprehention [a+i*b for i in range(n)]. b defaults to zero,
+        # so axn is equivalent to [a for i in range(n)]
+        #
+        # see https://prometheus.io/docs/prometheus/latest/configuration/unit_testing_rules/#series
         values: '1x60'
 
     alert_rule_test: