公司網(wǎng)絡(luò)更改重啟服務(wù)器后，發(fā)現(xiàn)Prometheus監(jiān)控中node節(jié)點三個掛掉了，實際上節(jié)點服務(wù)器是正常的，但是監(jiān)控的node_exporter請求http://IP:9100/metrics超過10秒沒有獲取返回數(shù)據(jù)則認(rèn)為服務(wù)掛掉。

到各個節(jié)點服務(wù)器用curl命令檢測多久返回數(shù)據(jù)

curl -o /dev/null -s -w '%{time_connect}:%{time_starttransfer}:%{time_total}\n' 'http://NodeIP:9100/metrics'

time_connect ：連接時間，從開始到TCP三次握手完成時間，這里面包括DNS解析的時候，如果想求連接時間，需要減去上面的解析時間；
time_starttransfer ：開始傳輸時間，從發(fā)起請求開始，到服務(wù)器返回第一個字段的時間；
time_total ：總時間；

可以看到time_connect時間是很快的，排除網(wǎng)絡(luò)問題。除了167返回時間正常其他幾個節(jié)點都是有問題的。

查看pod日志

ts=2023-01-11T06:11:08.189Z caller=stdlib.go:105 level=error caller="error encoding and sending metric family: write tcp 163:9100" msg="-> 167:40743: write: broken pipe"
ts=2023-01-11T06:11:08.189Z caller=stdlib.go:105 level=error caller="error encoding and sending metric family: write tcp 163:9100" msg="->.167:40743: write: broken pipe"

可以看到有大量的這種日志

參考資料： https://asktug.com/t/topic/153284/36 和 https://blog.csdn.net/lyf0327/article/details/99971590

有些說可以調(diào)大scrape_timeout這個時間，但是這個不是解決問題的根本

也有說調(diào)大node_exporter的yaml中的limit內(nèi)存和CPU,但是我這邊的node_exporter是沒有配置request和limit資源的，也不是這個問題，最后參考別人的配置文件

apiVersion: apps/v1
kind: DaemonSet
metadata:
  annotations:
    deprecated.daemonset.template.generation: "5"
    prometheus.io/scrape: "true"
  generation: 5
  labels:
    app: node-exporter
  name: node-exporter
  namespace: monitoring
spec:
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: node-exporter
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: node-exporter
      name: node-exporter
    spec:
      containers:
      - args:
        - --web.listen-address=$(HOSTIP):9100
        - --path.procfs=/host/proc
        - --path.sysfs=/host/sys
        - --path.rootfs=/host   # 修改了這個原來是/host/root
        - --collector.filesystem.ignored-mount-points=^/(dev|proc|sys|var/lib/docker/.+)($|/)
        - --collector.filesystem.ignored-fs-types=^(autofs|binfmt_misc|cgroup|configfs|debugfs|devpts|devtmpfs|fusectl|hugetlbfs|mqueue|overlay|proc|procfs|pstore|rpc_pipefs|securityfs|sysfs|tracefs)$
        - --log.level=debug
        env:
        - name: HOSTIP
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: status.hostIP
        image: prom/node-exporter:latest
        imagePullPolicy: IfNotPresent
        name: node-exporter
        ports:
        - containerPort: 9100
          hostPort: 9100
          protocol: TCP
        resources: {}
        securityContext:
          privileged: true
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /host/proc
          name: proc
        - mountPath: /host/sys
          name: sys
        - mountPath: /host     # 修改了這個原來是/rootfs
          name: rootfs
      dnsPolicy: ClusterFirst
      hostIPC: true
      hostNetwork: true
      hostPID: true
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
      tolerations:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
        operator: Exists
      volumes:
      - hostPath:
          path: /proc
        name: proc
      - hostPath:
          path: /sys
        name: sys
      - hostPath:
          path: /    
        name: rootfs
  updateStrategy:
    rollingUpdate:
      maxSurge: 0
      maxUnavailable: 1
    type: RollingUpdate

觀察了一天

根據(jù)上述修改后仍有問題，其中一個報權(quán)限不足

apiVersion: apps/v1
kind: DaemonSet
metadata:
  annotations:
    deprecated.daemonset.template.generation: "5"
    prometheus.io/scrape: "true"
  generation: 5
  labels:
    app: node-exporter
  name: node-exporter
  namespace: monitoring
spec:
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: node-exporter
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: node-exporter
      name: node-exporter
    spec:
      containers:
      - args:
        - --web.listen-address=$(HOSTIP):9100
        - --path.procfs=/host/proc
        - --path.sysfs=/host/sys
        - --path.rootfs=/host
        - --collector.filesystem.ignored-mount-points=^/(dev|proc|sys|var/lib/docker/.+)($|/)
        - --collector.filesystem.ignored-fs-types=^(autofs|binfmt_misc|cgroup|configfs|debugfs|devpts|devtmpfs|fusectl|hugetlbfs|mqueue|overlay|proc|procfs|pstore|rpc_pipefs|securityfs|sysfs|tracefs)$
        - --log.level=debug
        env:
        - name: HOSTIP
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: status.hostIP
        image: prom/node-exporter:latest
        imagePullPolicy: IfNotPresent
        name: node-exporter
        ports:
        - containerPort: 9100
          hostPort: 9100
          protocol: TCP
        resources: {}
        securityContext:
          privileged: true
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /host/proc
          name: proc
        - mountPath: /host/sys
          name: sys
        - mountPath: /host
          name: rootfs
      dnsPolicy: ClusterFirst
      hostIPC: true
      hostNetwork: true
      hostPID: true
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: 
        runAsUser: 0   # 添加該選項 默認(rèn)是nobody用戶 65534的uid
      terminationGracePeriodSeconds: 30
      tolerations:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
        operator: Exists
      volumes:
      - hostPath:
          path: /proc
        name: proc
      - hostPath:
          path: /sys
        name: sys
      - hostPath:
          path: /
        name: rootfs
  updateStrategy:
    rollingUpdate:
      maxSurge: 0
      maxUnavailable: 1
    type: RollingUpdate

再觀察一天最新的問題有重新出現(xiàn)

報大量的error encoding and sending metric family: write tcp 10.37.0.163:9100" msg="->10.37.0.167:50266: write: broken pip

查了很多資料最后一個資料比較有用

地址：https://github.com/prometheus/node_exporter/issues/2500文章來源地址http://www.zghlxwxcb.cn/news/detail-498567.html

我這邊的節(jié)點3個內(nèi)核是5.4.0-132，三個都是有問題的，而更高版本的內(nèi)核5.15.0是沒問題的
最終結(jié)論是內(nèi)核版本問題；
臨時解決方案是在node_exporter中添加環(huán)境變量GOMAXPROCS=1
永久解決是升級內(nèi)核