Alert Rule Examples

apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    prometheus: longhorn
    role: alert-rules
  name: prometheus-longhorn-rules
  namespace: monitoring
spec:
  groups:
  - name: longhorn.rules
    rules:
    - alert: LonghornVolumeActualSpaceUsedWarning
      annotations:
        description: The actual space used by Longhorn volume {{$labels.volume}} on {{$labels.node}} is at {{$value}}% capacity for
          more than 5 minutes.
        summary: The actual used space of Longhorn volume is over 90% of the capacity.
      expr: (longhorn_volume_actual_size_bytes / longhorn_volume_capacity_bytes) * 100 > 90
      for: 5m
      labels:
        issue: The actual used space of Longhorn volume {{$labels.volume}} on {{$labels.node}} is high.
        severity: warning
    - alert: LonghornVolumeStatusCritical
      annotations:
        description: Longhorn volume {{$labels.volume}} on {{$labels.node}} is Fault for
          more than 2 minutes.
        summary: Longhorn volume {{$labels.volume}} is Fault
      expr: longhorn_volume_robustness == 3
      for: 5m
      labels:
        issue: Longhorn volume {{$labels.volume}} is Fault.
        severity: critical
    - alert: LonghornVolumeStatusWarning
      annotations:
        description: Longhorn volume {{$labels.volume}} on {{$labels.node}} is Degraded for
          more than 5 minutes.
        summary: Longhorn volume {{$labels.volume}} is Degraded
      expr: longhorn_volume_robustness == 2
      for: 5m
      labels:
        issue: Longhorn volume {{$labels.volume}} is Degraded.
        severity: warning
    - alert: LonghornNodeStorageWarning
      annotations:
        description: The used storage of node {{$labels.node}} is at {{$value}}% capacity for
          more than 5 minutes.
        summary:  The used storage of node is over 70% of the capacity.
      expr: (longhorn_node_storage_usage_bytes / longhorn_node_storage_capacity_bytes) * 100 > 70
      for: 5m
      labels:
        issue: The used storage of node {{$labels.node}} is high.
        severity: warning
    - alert: LonghornDiskStorageWarning
      annotations:
        description: The used storage of disk {{$labels.disk}} on node {{$labels.node}} is at {{$value}}% capacity for
          more than 5 minutes.
        summary:  The used storage of disk is over 70% of the capacity.
      expr: (longhorn_disk_usage_bytes / longhorn_disk_capacity_bytes) * 100 > 70
      for: 5m
      labels:
        issue: The used storage of disk {{$labels.disk}} on node {{$labels.node}} is high.
        severity: warning
    - alert: LonghornNodeDown
      annotations:
        description: There are {{$value}} Longhorn nodes which have been offline for more than 5 minutes.
        summary: Longhorn nodes is offline
      expr: (avg(longhorn_node_count_total) or on() vector(0)) - (count(longhorn_node_status{condition="ready"} == 1) or on() vector(0)) > 0
      for: 5m
      labels:
        issue: There are {{$value}} Longhorn nodes are offline
        severity: critical
    - alert: LonghornInstanceManagerCPUUsageWarning
      annotations:
        description: Longhorn instance manager {{$labels.instance_manager}} on {{$labels.node}} has CPU Usage / CPU request is {{$value}}% for
          more than 5 minutes.
        summary: Longhorn instance manager {{$labels.instance_manager}} on {{$labels.node}} has CPU Usage / CPU request is over 300%.
      expr: (longhorn_instance_manager_cpu_usage_millicpu/longhorn_instance_manager_cpu_requests_millicpu) * 100 > 300
      for: 5m
      labels:
        issue: Longhorn instance manager {{$labels.instance_manager}} on {{$labels.node}} consumes 3 times the CPU request.
        severity: warning
    - alert: LonghornNodeCPUUsageWarning
      annotations:
        description: Longhorn node {{$labels.node}} has CPU Usage / CPU capacity is {{$value}}% for
          more than 5 minutes.
        summary: Longhorn node {{$labels.node}} experiences high CPU pressure for more than 5m.
      expr: (longhorn_node_cpu_usage_millicpu / longhorn_node_cpu_capacity_millicpu) * 100 > 90
      for: 5m
      labels:
        issue: Longhorn node {{$labels.node}} experiences high CPU pressure.
        severity: warning