告警触发流程

在prometheus配置里面创建告警规则

判断当前实例的状态是否正常，up=1代表正常，up=0代表失联，不正常

groups:
- name: general.rules
  rules:
  - alert: InstanceDown
    expr: up == 0
    for: 2m
    labels:
      severity: error
    annotations:
      summary: "Instance {{ $labels.instance }} 停止工作"
      description: "{{ $labels.instance }}: job {{ $labels.job }} 已经停止5分钟以上."

统计cpu，内存，文件系统的使用率，超过80%发送告警

groups:
- name: node.rules
  rules:
  - alert: NodeFilesystemUsage
    expr: 100 - (node_filesystem_free_bytes{fstype=~"ext4|xfs"} / node_filesystem_size_bytes{fstype=~"ext4|xfs"} * 100) > 80
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "{{$labels.instance}}: {{$labels.mountpoint }} 分区使用过高"
      description: "{{$labels.instance}}: {{$labels.mountpoint }} 分区使用大于 80% (当前值: {{ $value }})"
  - alert: NodeMemoryUsage
    expr: 100 - (node_memory_MemFree_bytes+node_memory_Cached_bytes+node_memory_Buffers_bytes) / node_memory_MemTotal_bytes * 100 > 80
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "{{$labels.instance}}: 内存使用过高"
      description: "{{$labels.instance}}: 内存使用大于 80% (当前值: {{ $value }})"
  - alert: NodeCPUUsage
    expr: 100 - (avg(irate(node_cpu_seconds_total{mode="idle"}[5m])) by (instance) * 100) > 80
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "{{$labels.instance}}: CPU使用过高"
      description: "{{$labels.instance}}: CPU使用大于 80% (当前值: {{ $value }})"

进入for评估周期中