groups:
- name: AllInstances
  rules:
  - alert: InstanceDown
    # Condition for alerting
    expr: up == 0
    for: 20s
    annotations:
      title: 'Instance {{ $labels.instance }} down'
      description: '{{ $labels.instance }} of job {{ $labels.job }} has been down for more than 20 seconds.'
    labels:
      severity: 'critical'