k8s pod资源配额对调度的影响

1. pod资源配额对调度的影响

  • 容器资源限制:

    • resources.limits.cpu

    • resources.limits.memory

  • 容器使用的最小资源需求,作为容器调度时资源分配的依据:

    • resources.requests.cpu
    • resources.requests.memory
  • 注释:

    ​ CPU单位:可以写m也可以写浮点数,例如0.5=500m,1=1000m

  • 参考示例

    apiVersion: v1
    kind: Pod
    metadata:
      name: web
    spec:
      containers:
      - name: web
        image: nginx
        resources:
          requests:              # 启动容器最小资源
            memory: "64Mi"
            cpu: "250m"
          limits:                 # 容器的最大资源限制
            memory: "128Mi"       # 容器的最大资源内存限制128M
            cpu: "500m"           # 容器的最大资源cpu的核数限制,500m=0.5核数
    
  • 注释

    1. CPU单位:可以写m也可以写浮点数,例如0.5=500m,1核=1000m

2. 案例

  • 编写案例模板

    [root@k8s-master yaml]# vim request-pod.yaml
    [root@k8s-master yaml]# cat request-pod.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: web
    spec:
      containers:
      - name: web
        image: nginx
        resources:
          requests:              # 启动容器最小资源
            memory: "64Mi"
            cpu: "250m"
          limits:                 # 容器的最大资源限制
            memory: "128Mi"       # 容器的最大资源内存限制128M
            cpu: "500m"           # 容器的最大资源cpu的核数限制,500m=0.5核数
    
    
  • 启动服务

    [root@k8s-master yaml]# kubectl apply -f request-pod.yaml 
    pod/web created
    
    
  • 查看服务

    [root@k8s-master yaml]# kubectl get pods
    NAME         READY   STATUS    RESTARTS   AGE
    init-demo    1/1     Running   0          21h
    pod-envars   1/1     Running   2          22h
    probe-demo   1/1     Running   0          24h
    web          1/1     Running   0          14s
    
  • 验证服务启动的资源配置限制

    [root@k8s-master yaml]# kubectl describe pods web 
    Name:         web
    Namespace:    default
    Priority:     0
    Node:         k8s-node2/192.168.0.203
    Start Time:   Mon, 30 Nov 2020 15:04:13 +0800
    Labels:       <none>
    Annotations:  cni.projectcalico.org/podIP: 10.244.169.158/32
                  cni.projectcalico.org/podIPs: 10.244.169.158/32
    Status:       Running
    IP:           10.244.169.158
    IPs:
      IP:  10.244.169.158
    Containers:
      web:
        Container ID:   docker://f895befae98eedb7fe8fc0b26852afd4023a793b8a7f1abbab7d58851f314651
        Image:          nginx
        Image ID:       docker-pullable://nginx@sha256:6b1daa9462046581ac15be20277a7c75476283f969cb3a61c8725ec38d3b01c3
        Port:           <none>
        Host Port:      <none>
        State:          Running
          Started:      Mon, 30 Nov 2020 15:04:23 +0800
        Ready:          True
        Restart Count:  0
        Limits:
          cpu:     500m
          memory:  128Mi
        Requests:
          cpu:        250m
          memory:     64Mi
        Environment:  <none>
        Mounts:
          /var/run/secrets/kubernetes.io/serviceaccount from default-token-8pppk (ro)
    Conditions:
      Type              Status
      Initialized       True 
      Ready             True 
      ContainersReady   True 
      PodScheduled      True 
    Volumes:
      default-token-8pppk:
        Type:        Secret (a volume populated by a Secret)
        SecretName:  default-token-8pppk
        Optional:    false
    QoS Class:       Burstable
    Node-Selectors:  <none>
    Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                     node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
    Events:
      Type    Reason     Age    From                Message
      ----    ------     ----   ----                -------
      Normal  Scheduled  4m28s  default-scheduler   Successfully assigned default/web to k8s-node2
      Normal  Pulling    4m23s  kubelet, k8s-node2  Pulling image "nginx"
      Normal  Pulled     4m18s  kubelet, k8s-node2  Successfully pulled image "nginx" in 4.71128787s
      Normal  Created    4m18s  kubelet, k8s-node2  Created container web
      Normal  Started    4m18s  kubelet, k8s-node2  Started container web
    
  • 怎么查看node节点资源配额

    [root@k8s-master pod]# kubectl  describe node k8s-node01 
    Name:               k8s-node01
    Roles:              <none>
    Labels:             beta.kubernetes.io/arch=amd64
                        beta.kubernetes.io/os=linux
                        kubernetes.io/arch=amd64
                        kubernetes.io/hostname=k8s-node01
                        kubernetes.io/os=linux
    Annotations:        kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
                        node.alpha.kubernetes.io/ttl: 0
                        projectcalico.org/IPv4Address: 172.17.0.13/20
                        projectcalico.org/IPv4IPIPTunnelAddr: 10.244.85.192
                        volumes.kubernetes.io/controller-managed-attach-detach: true
    CreationTimestamp:  Wed, 04 Aug 2021 14:31:44 +0800
    Taints:             <none>
    Unschedulable:      false
    Lease:
      HolderIdentity:  k8s-node01
      AcquireTime:     <unset>
      RenewTime:       Mon, 16 Aug 2021 22:33:39 +0800
    Conditions:
      Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
      ----                 ------  -----------------                 ------------------                ------                       -------
      NetworkUnavailable   False   Wed, 04 Aug 2021 14:35:31 +0800   Wed, 04 Aug 2021 14:35:31 +0800   CalicoIsUp                   Calico is running on this node
      MemoryPressure       False   Mon, 16 Aug 2021 22:28:53 +0800   Wed, 04 Aug 2021 14:31:44 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
      DiskPressure         False   Mon, 16 Aug 2021 22:28:53 +0800   Wed, 04 Aug 2021 14:31:44 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
      PIDPressure          False   Mon, 16 Aug 2021 22:28:53 +0800   Wed, 04 Aug 2021 14:31:44 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
      Ready                True    Mon, 16 Aug 2021 22:28:53 +0800   Wed, 04 Aug 2021 14:34:45 +0800   KubeletReady                 kubelet is posting ready status
    Addresses:
      InternalIP:  172.17.0.13
      Hostname:    k8s-node01
    Capacity:
      cpu:                2
      ephemeral-storage:  51473868Ki
      hugepages-1Gi:      0
      hugepages-2Mi:      0
      memory:             3880180Ki
      pods:               110
    Allocatable:
      cpu:                2
      ephemeral-storage:  47438316671
      hugepages-1Gi:      0
      hugepages-2Mi:      0
      memory:             3777780Ki
      pods:               110
    System Info:
      Machine ID:                 96285cf085224a608d1d6ad0cbf21e97
      System UUID:                96285CF0-8522-4A60-8D1D-6AD0CBF21E97
      Boot ID:                    c84c93c7-eb6f-4e92-884b-01c8eddfb4f8
      Kernel Version:             3.10.0-1160.11.1.el7.x86_64
      OS Image:                   CentOS Linux 7 (Core)
      Operating System:           linux
      Architecture:               amd64
      Container Runtime Version:  docker://20.10.8
      Kubelet Version:            v1.19.0
      Kube-Proxy Version:         v1.19.0
    PodCIDR:                      10.244.1.0/24
    PodCIDRs:                     10.244.1.0/24
    Non-terminated Pods:          (4 in total)
      Namespace                   Name                                        CPU Requests  CPU Limits  Memory Requests  Memory Limits  AGE
      ---------                   ----                                        ------------  ----------  ---------------  -------------  ---
      kube-system                 calico-kube-controllers-5f6cfd688c-pg27v    0 (0%)        0 (0%)      0 (0%)           0 (0%)         12d
      kube-system                 calico-node-xdc7h                           250m (12%)    0 (0%)      0 (0%)           0 (0%)         12d
      kube-system                 coredns-6d56c8448f-msj5b                    100m (5%)     0 (0%)      70Mi (1%)        170Mi (4%)     11d
      kube-system                 kube-proxy-mcnn7                            0 (0%)        0 (0%)      0 (0%)           0 (0%)         12d
    Allocated resources:
      (Total limits may be over 100 percent, i.e., overcommitted.)
      Resource           Requests    Limits
      --------           --------    ------
      cpu                350m (17%)  0 (0%)
      memory             70Mi (1%)   170Mi (4%)
      ephemeral-storage  0 (0%)      0 (0%)
      hugepages-1Gi      0 (0%)      0 (0%)
      hugepages-2Mi      0 (0%)      0 (0%)
    Events:              <none>
    
原文地址:https://www.cnblogs.com/scajy/p/15481759.html