groups:
- name: cpu
  interval: 15s
  rules:
  - alert: HighCpuUsage
    expr: 1 - avg(irate(node_cpu_seconds_total{mode="idle"}[1m])) by (hostname) > 0.8
    for: 30s
    labels:
      severity: warning
    annotations:
      summary: "主机 {{ $labels.hostname }} CPU 使用率过高"
      description: "CPU 使用率: {{ $value | humanizePercentage }}"