步骤

github地址：https://github.com/percona/mongodb_exporter

mongodb_exporter可以本地部署，也可以用docker部署。我这里是放在了k8s里。namespace是rancher的cattle-monitoring-system。相关yaml如下：

mongo-exporter-deploy.yaml

注意修改mongodb.uri的地址。格式是：mongodb.uri ：mongodb://username:password@localhost:27017/mydatabase?authSource=admin&authenticationDatabase=myauthdb

kind: Deployment
apiVersion: apps/v1
metadata:
  name: mongo-exporter
  namespace: cattle-monitoring-system
  labels:
    app: mongo-exporter
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongo-exporter
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: mongo-exporter
    spec:
      containers:
        - name: mongo-exporter
          image: 'percona/mongodb_exporter:0.20'
          args:
            - '--web.listen-address=:9216'
            - '--mongodb.uri=mongodb://admin:xxx@mongodb-svc.namespace:27017/'
          ports:
            - name: 9216tcp02
              containerPort: 9216
              protocol: TCP
          resources: {}
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
          imagePullPolicy: IfNotPresent
          securityContext:
            capabilities: {}
      restartPolicy: Always
      terminationGracePeriodSeconds: 30
      dnsPolicy: ClusterFirst
      securityContext: {}
      schedulerName: default-scheduler
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 25%
      maxSurge: 25%
  revisionHistoryLimit: 10
  progressDeadlineSeconds: 600

mongo-exporter-svc.yaml

apiVersion: v1
kind: Service
metadata:
  labels:
    app: mongo-exporter
  name: mongo-exporter
  namespace: cattle-monitoring-system
spec:
  ports:
  - name: http
    port: 9216
    protocol: TCP
    targetPort: 9216
  selector:
    app: mongo-exporter
  sessionAffinity: None
  type: ClusterIP

mongo-exporter-servicemonitor.yaml

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    app: mongo-exporter
  name: mongo-exporter
  namespace: cattle-monitoring-system
spec:
  endpoints:
  - interval: 30s
    path: /metrics
    port: http
    scrapeTimeout: 10s
  jobLabel: mongo-exporter
  selector:
    matchLabels:
      app: mongo-exporter

mongo-exporter-prometheusrule.yaml

apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  name: mongo-exporter
  namespace: cattle-monitoring-system
spec:
  groups:
  - name: PerconaMongodbExporter
    rules:
      - alert: MongodbDown
        expr: 'mongodb_up == 0'
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: MongoDB Down (instance {{ $labels.instance }})
          description: "MongoDB instance is down\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbReplicaMemberUnhealthy
        expr: 'mongodb_rs_members_health == 0'
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: Mongodb replica member unhealthy (instance {{ $labels.instance }})
          description: "MongoDB replica member is not healthy\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbReplicationLag
        expr: '(mongodb_rs_members_optimeDate{member_state="PRIMARY"} - on (set) group_right mongodb_rs_members_optimeDate{member_state="SECONDARY"}) / 1000 > 10'
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: MongoDB replication lag (instance {{ $labels.instance }})
          description: "Mongodb replication lag is more than 10s\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbReplicationHeadroom
        expr: 'sum(avg(mongodb_mongod_replset_oplog_head_timestamp - mongodb_mongod_replset_oplog_tail_timestamp)) - sum(avg(mongodb_rs_members_optimeDate{member_state="PRIMARY"} - on (set) group_right mongodb_rs_members_optimeDate{member_state="SECONDARY"})) <= 0'
        for: 0m
        labels:
          severity: critical
        annotations:
          summary: MongoDB replication headroom (instance {{ $labels.instance }})
          description: "MongoDB replication headroom is <= 0\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbNumberCursorsOpen
        expr: 'mongodb_ss_metrics_cursor_open{csr_type="total"} > 10 * 1000'
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: MongoDB number cursors open (instance {{ $labels.instance }})
          description: "Too many cursors opened by MongoDB for clients (> 10k)\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbCursorsTimeouts
        expr: 'increase(mongodb_ss_metrics_cursor_timedOut[1m]) > 100'
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: MongoDB cursors timeouts (instance {{ $labels.instance }})
          description: "Too many cursors are timing out\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbTooManyConnections
        expr: 'avg by(instance) (rate(mongodb_ss_connections{conn_type="current"}[1m])) / avg by(instance) (sum (mongodb_ss_connections) by (instance)) * 100 > 80'
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: MongoDB too many connections (instance {{ $labels.instance }})
          description: "Too many connections (> 80%)\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

      - alert: MongodbVirtualMemoryUsage
        expr: '(sum(mongodb_ss_mem_virtual) BY (instance) / sum(mongodb_ss_mem_resident) BY (instance)) > 3'
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: MongoDB virtual memory usage (instance {{ $labels.instance }})
          description: "High memory usage\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}

grafana模板

使用的是官网的模板：
https://grafana.com/grafana/dashboards/12079-mongodb/
https://grafana.com/grafana/dashboards/14997-mongodb/
https://grafana.com/grafana/dashboards/7359-mongodb-replset/

报错

如果使用的是最新版本的exporter，而mongodb版本较低，会报下面的错：server reports wire version 5,but this version of the Go driver requires at least 6 (MongoDB 3.6)