node_exporter 配置

Prometheus监控服务器

监控服务器CPU、内存、磁盘、I/O等信息，首先需要安装node_exporter。node_exporter的作用是用于机器系统数据收集。

下载地址： https://github.com/prometheus/node_exporter/releases/
https://prometheus.io/download/

wget https://github.com/prometheus/node_exporter/releases/download/v0.18.1/node_exporter-0.18.0.linux-amd64.tar.gz

tar xvf node_exporter-0.18.0.linux-amd64.tar.gz
mv node_exporter-0.18.0.linux-amd64 /usr/local/bin/node_exporter

创建用户

groupadd prometheus
useradd -g prometheus -m -d /var/lib/prometheus -s /sbin/nologin prometheus
chown prometheus.prometheus -R /usr/local/prometheus

创建Systemd服务

cat > /etc/systemd/system/node_exporter.service << EOF
[Unit]
Description=node_exporter
Documentation=https://prometheus.io/
After=network.target
[Service]
Type=simple
User=prometheus
ExecStart=/usr/local/bin/node_exporter
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

启动

systemctl start node_exporter

systemctl status node_exporter
● node_exporter.service - node_exporter
   Loaded: loaded (/etc/systemd/system/node_exporter.service; disabled; vendor preset: disabled)
   Active: active (running) since 三 2019-06-05 09:18:56 GMT; 3s ago
 Main PID: 11050 (node_exporter)
   CGroup: /system.slice/node_exporter.service
           └─11050 /usr/local/prometheus/node_exporter/node_exporter

systemctl enable node_exporter

Node Exporter默认的抓取地址为http://IP:9100/metrics

配置prometheus

vim  /usr/local/prometheus/prometheus.yml

  - job_name: 'linux'
    static_configs:
      - targets: ['localhost:9100']
        labels:
          instance: node1

prometheus.yml中一共定义了两个监控：一个是监控prometheus自身服务，另一个是监控Linux服务器。这里给个完整的示例：

scrape_configs:

  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

  - job_name: 'linux'
    static_configs:
      - targets: ['NODE_IP:9100']
        labels:
          instance: node1

重启Prometheus

systemctl restart prometheus

访问Prometheus Web，在Status->Targets页面下，我们可以看到我们配置的两个Target，它们的State为UP。

Prometheus针对nodes告警规则配置

groups:
- name: example
  rules:
 
  - alert: 实例丢失
    expr: up{job="node-exporter"} == 0
    for: 1m
    labels:
      severity: page
    annotations:
      summary: "服务器实例 {{ $labels.instance }} 丢失"
      description: "{{ $labels.instance }} 上的任务 {{ $labels.job }} 已经停止了 1 分钟已上了"
 
  - alert: 磁盘容量小于 5%
    expr: 100 - ((node_filesystem_avail_bytes{job="node-exporter",mountpoint=~".*",fstype=~"ext4|xfs|ext2|ext3"} * 100) / node_filesystem_size_bytes {job="node-exporter",mountpoint=~".*",fstype=~"ext4|xfs|ext2|ext3"}) > 95
    for: 30s
    annotations:
      summary: "服务器实例 {{ $labels.instance }} 磁盘不足 告警通知"
      description: "{{ $labels.instance }}磁盘 {{ $labels.device }} 资源 已不足 5%, 当前值: {{ $value }}"
 
  - alert: "内存容量小于 20%"
    expr: ((node_memory_MemTotal_bytes - node_memory_MemFree_bytes - node_memory_Buffers_bytes - node_memory_Cached_bytes) / (node_memory_MemTotal_bytes )) * 100 > 80
    for: 30s
    labels:
      severity: warning
    annotations:
      summary: "服务器实例 {{ $labels.instance }} 内存不足 告警通知"
      description: "{{ $labels.instance }}内存资源已不足 20%,当前值: {{ $value }}"
 
  - alert: "CPU 平均负载大于 4 个"
    expr: node_load5 > 4
    for: 30s
    annotations:
      sumary: "服务器实例 {{ $labels.instance }} CPU 负载 告警通知"
      description: "{{ $labels.instance }}CPU 平均负载(5 分钟) 已超过 4 ,当前值: {{ $value }}"
 
  - alert: "磁盘读 I/O 超过 30MB/s"
    expr: irate(node_disk_read_bytes_total{device="sda"}[1m]) > 30000000
    for: 30s
    annotations:
      sumary: "服务器实例 {{ $labels.instance }} I/O 读负载 告警通知"
      description: "{{ $labels.instance }}I/O 每分钟读已超过 30MB/s,当前值: {{ $value }}"
 
  - alert: "磁盘写 I/O 超过 30MB/s"
    expr: irate(node_disk_written_bytes_total{device="sda"}[1m]) > 30000000
    for: 30s
    annotations:
      sumary: "服务器实例 {{ $labels.instance }} I/O 写负载 告警通知"
      description: "{{ $labels.instance }}I/O 每分钟写已超过 30MB/s,当前值: {{ $value }}"
 
  - alert: "网卡流出速率大于 10MB/s"
    expr: (irate(node_network_transmit_bytes_total{device!~"lo"}[1m]) / 1000) > 1000000
    for: 30s
    annotations:
      sumary: "服务器实例 {{ $labels.instance }} 网卡流量负载 告警通知"
      description: "{{ $labels.instance }}网卡 {{ $labels.device }} 流量已经超过 10MB/s, 当前值: {{ $value }}"
 
  - alert: "CPU 使用率大于 90%"
    expr: 100 - ((avg by (instance,job,env)(irate(node_cpu_seconds_total{mode="idle"}[30s]))) *100) > 90
    for: 30s
    annotations:
      sumary: "服务器实例 {{ $labels.instance }} CPU 使用率 告警通知"
      description: "{{ $labels.instance }}CPU 使用率已超过 90%, 当前值: {{ $value }}"