---
groups:
  - name: Redis

    rules:
      - alert: RedisDown
        expr: >-
          redis_up == 0
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Redis down (instance {{ $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 (instance {{ $labels.instance }})
          description: |-
            Redis cluster has no node marked as 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 (instance {{ $labels.instance }})
          description: |-
            Redis cluster has too many nodes marked as 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 (instance {{ $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 (instance {{ $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 (instance {{ $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 (instance {{ $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 (instance {{ $labels.instance }})
          description: |-
            Redis is running out of system memory (> 90%).

              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 (instance {{ $labels.instance }})
          description: |-
            Redis is running out of configured maxmemory (> 90%).

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

      - alert: RedisTooManyConnections
        expr: >-
          redis_connected_clients > 100
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: Redis too many connections (instance {{ $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 (instance {{ $labels.instance }})
          description: |-
            Redis instance should have more connections (> 1).

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

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

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