*: add postgres-exporter mixin

assets/postgres-exporter/alerts.yaml

@@ -0,0 +1,105 @@
+groups:
+- name: PostgreSQL
+  rules:
+  - alert: PostgreSQLMaxConnectionsReached
+    annotations:
+      description: '{{ $labels.instance }} is exceeding the currently configured maximum
+        Postgres connection limit (current value: {{ $value }}s). Services may be
+        degraded - please take immediate action (you probably need to increase max_connections
+        in the Docker image and re-deploy.'
+      summary: '{{ $labels.instance }} has maxed out Postgres connections.'
+    expr: |
+      sum by (instance) (pg_stat_activity_count{})
+      >=
+      sum by (instance) (pg_settings_max_connections{})
+      -
+      sum by (instance) (pg_settings_superuser_reserved_connections{})
+    for: 1m
+    labels:
+      severity: warning
+  - alert: PostgreSQLHighConnections
+    annotations:
+      description: '{{ $labels.instance }} is exceeding 80% of the currently configured
+        maximum Postgres connection limit (current value: {{ $value }}s). Please check
+        utilization graphs and confirm if this is normal service growth, abuse or
+        an otherwise temporary condition or if new resources need to be provisioned
+        (or the limits increased, which is mostly likely).'
+      summary: '{{ $labels.instance }} is over 80% of max Postgres connections.'
+    expr: |
+      sum by (instance) (pg_stat_activity_count{})
+      >
+      (
+        sum by (instance) (pg_settings_max_connections{})
+        -
+        sum by (instance) (pg_settings_superuser_reserved_connections{})
+      ) * 0.8
+    for: 10m
+    labels:
+      severity: warning
+  - alert: PostgreSQLDown
+    annotations:
+      description: '{{ $labels.instance }} is rejecting query requests from the exporter,
+        and thus probably not allowing DNS requests to work either. User services
+        should not be effected provided at least 1 node is still alive.'
+      summary: 'PostgreSQL is not processing queries: {{ $labels.instance }}'
+    expr: pg_up{} != 1
+    for: 1m
+    labels:
+      severity: warning
+  - alert: PostgreSQLSlowQueries
+    annotations:
+      description: 'PostgreSQL high number of slow queries {{ $labels.cluster }} for
+        database {{ $labels.datname }} with a value of {{ $value }} '
+      summary: 'PostgreSQL high number of slow on {{ $labels.cluster }} for database
+        {{ $labels.datname }} '
+    expr: |
+      avg by (datname) (
+        rate (
+          pg_stat_activity_max_tx_duration{datname!~"template.*",}[2m]
+        )
+      ) > 2 * 60
+    for: 2m
+    labels:
+      severity: warning
+  - alert: PostgreSQLQPS
+    annotations:
+      description: PostgreSQL high number of queries per second on {{ $labels.cluster
+        }} for database {{ $labels.datname }} with a value of {{ $value }}
+      summary: PostgreSQL high number of queries per second {{ $labels.cluster }}
+        for database {{ $labels.datname }}
+    expr: |
+      avg by (datname) (
+        irate(
+          pg_stat_database_xact_commit{datname!~"template.*",}[5m]
+        )
+        +
+        irate(
+          pg_stat_database_xact_rollback{datname!~"template.*",}[5m]
+        )
+      ) > 10000
+    for: 5m
+    labels:
+      severity: warning
+  - alert: PostgreSQLCacheHitRatio
+    annotations:
+      description: PostgreSQL low on cache hit rate on {{ $labels.cluster }} for database
+        {{ $labels.datname }} with a value of {{ $value }}
+      summary: PostgreSQL low cache hit rate on {{ $labels.cluster }} for database
+        {{ $labels.datname }}
+    expr: |
+      avg by (datname) (
+        rate(pg_stat_database_blks_hit{datname!~"template.*",}[5m])
+        /
+        (
+          rate(
+            pg_stat_database_blks_hit{datname!~"template.*",}[5m]
+          )
+          +
+          rate(
+            pg_stat_database_blks_read{datname!~"template.*",}[5m]
+          )
+        )
+      ) < 0.98
+    for: 5m
+    labels:
+      severity: warning