Add an alert for unusually low apache request rates

diff --git a/cookbooks/prometheus/templates/default/alert_rules.yml.erb b/cookbooks/prometheus/templates/default/alert_rules.yml.erb
index b928520ed2756af7c741e5f8c446e0874e63e47c..4b5a0c60f2e14517c5d8b681001d01e382aa2d57 100644 (file)
--- a/cookbooks/prometheus/templates/default/alert_rules.yml.erb
+++ b/cookbooks/prometheus/templates/default/alert_rules.yml.erb
@@ -52,6 +52,13 @@ groups:
           alertgroup: "{{ $labels.instance }}"
         annotations:
           busy_workers: "{{ $value | humanizePercentage }}"
+      - alert: apache low request rate
+        expr: rate(apache_accesses_total[$__rate_interval]) / rate(apache_accesses_total[$__rate_interval] offset 1w) < 0.25 and rate(apache_accesses_total[1h] offset 1w) > 2
+        for: 15m
+        labels:
+          alertgroup: "{{ $labels.instance }}"
+        annotations:
+          request_rate: "{{ $value | humanizePercentage }}"
   - name: chef
     rules:
       - alert: chef client not running