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十九 容器资源限制

起始值 requests 最低保障

终结值 limits 硬限制

  • CPU

    1 颗 CPU = 1000 millicores 0.5 颗 CPU = 500 m

  • 内存

    Ei、Pi、Ti、Gi、Mi、Ki

19.1 资源限制

  • 清单格式，详见：kubectl explain pods.spec.containers.resources

    resources # 资源限制 limits <map[string]string> # 资源最高限制 cpu # 单位 m memory # 单位 Gi、Mi requests <map[string]string> # 资源最低要求 cpu # 单位 m memory # 单位 Gi、Mi

  • 清单示例，node 节点的 CPU 为 12 核心，cpu limits 设置为 1000m 也就是允许

    apiVersion: v1 kind: Pod metadata: name: pod-resources-demo namespace: default labels: app: myapp tier: frontend spec: containers:

    • name: nginx image: ikubernetes/stress-ng command:
      • “/usr/bin/stress-ng” #- “-m 1” # 以单线程压测内存
      • “-c 1” # 以单线程压测CPU
      • “–metrics-brief” ports:
      • name: http containerPort: 80
      • name: https containerPort: 443 resources: requests: cpu: 1000m # 它决定在预选阶段淘汰哪些主机 memory: 512Mi limits: cpu: 1000m # 表示限制容器使用 node 节点的一颗 CPU，无论多少进程，它们最多只能占用 node 节点的可 CPU memory: 512Mi

  • 查看结果

    Mem: 855392K used, 139916K free, 10188K shrd, 796K buff, 350368K cached CPU0: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU1: 100% usr 0% sys 0% nic 0% idle 0% io 0% irq 0% sirq # 占满了一颗 CPU CPU2: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU3: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU4: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU5: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU6: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU7: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU8: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU9: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU10: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq CPU11: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq Load average: 0.84 0.50 0.40 3/485 11 PID PPID USER STAT VSZ %VSZ CPU %CPU COMMAND 6 1 root R 6888 1% 1 8% {stress-ng-cpu} /usr/bin/stress-ng -c 1 –metrics-brief 1 0 root S 6244 1% 10 0% /usr/bin/stress-ng -c 1 –metrics-brief 7 0 root R 1504 0% 11 0% top

    • 19.2 qos 质量管理

    • GuranteedW

      每个容器同时设置了 CPU 和内存的 requests 和 limits，而且 cpu.limits = cpu.requests memory.limits = memory.requests 那么它将优先被调度

    • Burstable

      至少有一个容器设置 CPU 或内存资源的 requests 属性

      那么它将具有中等优先级

    • BestEffort

      没有任何一个容器设置了 requests 或 limits 属性

      那么它将只有最低优先级，当资源不够用的时候，这个容器可能最先被终止，以腾出资源来，为 Burstable 和 Guranteed

    • oom 策略

      最先杀死占用量和需求量的比例大的

    参考链接

    • Kubernetes官网教程 <https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/>__
    • Kubernetes中文社区 <https://www.kubernetes.org.cn/k8s>__
    • 从Kubernetes到Cloud Native <https://jimmysong.io/kubernetes-handbook/cloud-native/from-kubernetes-to-cloud-native.html>__
    • Kubernetes Handbook <https://www.bookstack.cn/read/feiskyer-kubernetes-handbook/appendix-ecosystem.md>__
    • Kubernetes从入门到实战 <https://www.kancloud.cn/huyipow/kubernetes/722822>__
    • Kubernetes指南 <https://kubernetes.feisky.xyz/>__
    • awesome-kubernetes <https://ramitsurana.github.io/awesome-kubernetes/>__
    • 从Docker到Kubernetes进阶 <https://www.qikqiak.com/k8s-book/>__
    • python微服务实战 <https://www.qikqiak.com/tdd-book/>__
    • 云原生之路 <https://jimmysong.io/kubernetes-handbook/cloud-native/from-kubernetes-to-cloud-native.html>__
    • CNCF Cloud Native Interactive Landscape <https://landscape.cncf.io/>__

    视频

    
-  `微服务容器化实战 <https://www.acfun.cn/v/ac10232871>`__