---
groups:
  - name: Redis

    rules:
      - alert: RedisDown
        expr: >-
          redis_up == 0
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis down at {{ $labels.instance }}.
          description: |-
            Redis instance is down.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisMissingMaster
        expr: >-
          (count(redis_instance_info{role="master"}) or vector(0))
          < 1
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis missing master at {{ $labels.instance }}).
          description: |-
            Redis cluster has no node marked as a master.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisTooManyMasters
        expr: >-
          count(redis_instance_info{role="master"}) > 1
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis too many masters at {{ $labels.instance }}.
          description: |-
            Redis cluster has too many nodes marked as a master.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisDisconnectedSlaves
        expr: >-
          count without (instance, job) (redis_connected_slaves)
          - sum without (instance, job) (redis_connected_slaves)
          - 1
          > 1
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis disconnected slaves at {{ $labels.instance }}.
          description: |-
            Redis is not replicating for all slaves.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisReplicationBroken
        expr: >-
          delta(redis_connected_slaves[1m]) < 0
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis replication broken at {{ $labels.instance }}.
          description: |-
            Redis instance lost a slave.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisClusterFlapping
        expr: >-
          changes(redis_connected_slaves[1m]) > 1
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: Redis cluster flapping at {{ $labels.instance }}.
          description: |-
            Changes have been detected in the Redis replica connection. This can occur when replica nodes lose connection to the master and reconnect (a.k.a flapping).

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisMissingBackup
        expr: >-
          time() - redis_rdb_last_save_timestamp_seconds
          > 60 * 60 * 24
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis missing backup at {{ $labels.instance }}.
          description: |-
            Redis has not been backed up for 24 hours.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisOutOfSystemMemory
        expr: >-
          redis_memory_used_bytes
          /
          redis_total_system_memory_bytes * 100
          > 90
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: Redis out of system memory at {{ $labels.instance }}.
          description: |-
            Redis is running out of system memory.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisOutOfConfiguredMaxmemory
        expr: >-
          redis_memory_max_bytes != 0
          and
          (
            redis_memory_used_bytes
            /
            redis_memory_max_bytes * 100
            > 90
          )
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: Redis out of configured maxmemory at {{ $labels.instance }}.
          description: |-
            Redis is running out of configured maxmemory.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisTooManyConnections
        expr: >-
          redis_connected_clients > 100
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: Redis too many connections at {{ $labels.instance }}.
          description: |-
            Redis instance has too many connections.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisNotEnoughConnections
        expr: >-
          redis_connected_clients < 1
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: Redis not enough connections at {{ $labels.instance }}.
          description: |-
            Redis instance should have more connections.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}

      - alert: RedisRejectedConnections
        expr: >-
          increase(redis_rejected_connections_total[1m]) > 0
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis rejected connections at {{ $labels.instance }}.
          description: |-
            Some connections to Redis have been rejected.

            VALUE = {{ $value }}
            LABELS = {{ $labels }}