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