chore: Adding initial mariadb alerts focused on replication status

Author: the2hill

base-helm-configs/prometheus/rules/mariadb_alerting_rules.yaml

@@ -0,0 +1,38 @@
+additionalPrometheusRulesMap:
+  openstack-services-rabbitmq:
+    groups:
+      - name: mariadb-alerts
+        rules:
+          - alert: MariaDBDown
+            expr: mysql_up != 1
+            for: 5m
+            labels:
+              severity: critical
+            annotations:
+              summary: MariaDB not up and running, immediate attention is required.
+              description: "MariaDB {{$labels.job}} on {{$labels.instance}} is not up."
+          - alert: MysqlTooManyConnections(>80%)
+            expr: max_over_time(mysql_global_status_threads_connected[1m]) / mysql_global_variables_max_connections * 100 > 80
+            for: 2m
+            labels:
+              severity: warning
+            annotations:
+              summary: MySQL too many connections (> 80%) (instance {{ $labels.instance }})
+              description: "More than 80% of MySQL connections are in use on {{ $labels.instance }}\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"
+          - alert: MariaDBReplicationErrors
+            expr: mysql_slave_status_last_sql_errno != 0 or mysql_slave_status_last_io_errno != 0 or mysql_slave_status_last_errno != 0
+            for: 5m
+            labels:
+              severity: critical
+            annotations:
+              summary: MariaDB is reporting replication errors from {{$labels.instance}}, immediate attention is required.
+              description: "MariaDB {{$labels.job}} on {{$labels.instance}} is reporting replication errors."
+          - alert: MysqlSlaveReplicationLag
+            expr: ( (mysql_slave_status_seconds_behind_master - mysql_slave_status_sql_delay) and ON (instance) mysql_slave_status_master_server_id > 0 ) > 30
+            for: 1m
+            labels:
+              severity: critical
+            annotations:
+              summary: MySQL Slave replication lag (instance {{ $labels.instance }})
+              description: "MySQL replication lag on {{ $labels.instance }}\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"
+