461 lines
15 KiB
Markdown
461 lines
15 KiB
Markdown
<!--
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---
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title: Assign CPU Resources to Containers and Pods
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content_template: templates/task
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weight: 20
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---
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-->
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---
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title: 为容器和 Pods 分配 CPU 资源
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content_template: templates/task
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weight: 20
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---
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{{% capture overview %}}
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<!--
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This page shows how to assign a CPU *request* and a CPU *limit* to
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a container. Containers cannot use more CPU than the configured limit.
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Provided the system has CPU time free, a container is guaranteed to be
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allocated as much CPU as it requests.
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-->
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此页面显示如何将 CPU *request* 和 CPU *limit* 分配给一个容器。容器使用的 CPU 不能超过配额限制。
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如果系统有空闲的 CPU 时间,则可以保证根据请求给容器分配尽可能多的 CPU 资源。
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{{% /capture %}}
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{{% capture prerequisites %}}
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{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
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<!--
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Each node in your cluster must have at least 1 CPU.
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A few of the steps on this page require you to run the
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[metrics-server](https://github.com/kubernetes-incubator/metrics-server)
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service in your cluster. If you have the metrics-server
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running, you can skip those steps.
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If you are running {{< glossary_tooltip term_id="minikube" >}}, run the
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following command to enable metrics-server:
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-->
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集群中的每个节点必须至少具有 1 个 CPU。
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此页面上的一些步骤要求您在集群中运行[metrics-server](https://github.com/kubernetes-incubator/metrics-server)
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服务。如果您的集群中已经有正在运行的 metrics-server 服务,那么您可以跳过这些步骤。
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如果您正在运行{{< glossary_tooltip term_id="minikube" >}},请运行以下命令启用 metrics-server:
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```shell
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minikube addons enable metrics-server
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```
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<!--
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To see whether metrics-server (or another provider of the resource metrics
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API, `metrics.k8s.io`) is running, type the following command:
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-->
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查看是 metrics-server(或者其他资源度量 API 服务提供者,`metrics.k8s.io` )是否正在运行,请键入以下命令:
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```shell
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kubectl get API services
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```
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<!--
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If the resource metrics API is available, the output will include a
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reference to `metrics.k8s.io`.
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-->
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如果资源指标 API 可用,则会输出将包含一个参考信息 `metrics.k8s.io`。
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```
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NAME
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v1beta1.metrics.k8s.io
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```
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{{% /capture %}}
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{{% capture steps %}}
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<!--
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## Create a namespace
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Create a {{< glossary_tooltip term_id="namespace" >}} so that the resources you
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create in this exercise are isolated from the rest of your cluster.
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-->
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## 创建一个命名空间
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创建一个命名空间 {{< glossary_tooltip term_id="namespace" >}},以便在本练习中创建的资源与集群的其余部分资源隔离。
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```shell
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kubectl create namespace CPU -example
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```
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<!--
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## Specify a CPU request and a CPU limit
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To specify a CPU request for a container, include the `resources:requests` field
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in the Container resource manifest. To specify a CPU limit, include `resources:limits`.
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In this exercise, you create a Pod that has one container. The container has a request
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of 0.5 CPU and a limit of 1 CPU. Here is the configuration file for the Pod:
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{{< codenew file="pods/resource/cpu-request-limit.yaml" >}}
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The `args` section of the configuration file provides arguments for the container when it starts.
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The `-cpus "2"` argument tells the Container to attempt to use 2 CPUs.
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Create the Pod:
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-->
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## 指定一个 CPU 请求和 CPU 限制
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要为容器指定 CPU 请求,请包含 `resources:requests` 字段
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在容器资源清单中。要指定 CPU 限制,请包含 `resources:limits`。
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在本练习中,您将创建一个具有一个容器的 Pod。容器将会请求 0.5 个 CPU,而且最多限制使用 1 个 CPU。
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这是 Pod 的配置文件:
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{{< codenew file="pods/resource/cpu-request-limit.yaml" >}}
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配置文件的 `args` 部分提供了容器启动时的参数。
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-cpus "2"参数告诉容器尝试使用 2 个 CPU。
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创建 Pod 命令如下:
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```shell
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kubectl apply -f https://k8s.io/examples/pods/resource/cpu-request-limit.yaml --namespace=cpu-example
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```
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<!--
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Verify that the Pod is running:
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-->
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验证上述创建的 Pod 处于 Running 状态
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```shell
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kubectl get pod cpu-demo --namespace=cpu-example
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```
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<!--
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View detailed information about the Pod:
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-->
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查看显示关于 Pod 的详细信息
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```shell
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kubectl get pod cpu-demo --output=yaml --namespace=cpu-example
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```
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<!--
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The output shows that the one container in the Pod has a CPU request of 500 milliCPU
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and a CPU limit of 1 CPU.
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-->
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输出显示 Pod 中的一个容器的 CPU 请求为 500 milli CPU,并且 CPU 限制为 1 个 CPU。
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```yaml
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resources:
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limits:
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CPU : "1"
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requests:
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CPU : 500m
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```
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<!--
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Use `kubectl top` to fetch the metrics for the pod:
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-->
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使用 `kubectl top` 命令来获取该 Pod 的指标数据:
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```shell
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kubectl top pod cpu-demo --namespace=cpu-example
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```
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<!--
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This example output shows that the Pod is using 974 milliCPU, which is
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just a bit less than the limit of 1 CPU specified in the Pod configuration.
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-->
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此示例的输出,显示 Pod 使用的是974 milliCPU,即仅略低于 Pod 配置中指定的 1 个 CPU 的限制。
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```
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NAME CPU (cores) MEMORY(bytes)
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CPU -demo 974m <something>
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```
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<!--
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Recall that by setting `-cpu "2"`, you configured the Container to attempt to use 2 CPUs, but the Container is only being allowed to use about 1 CPU. The container's CPU use is being throttled, because the container is attempting to use more CPU resources than its limit.
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-->
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回想一下,通过设置 `- CPU "2"`,您将容器配置为尝试使用 2 个 CPU,但是只允许容器使用大约 1 个 CPU。容器的 CPU 使用量受到限制,因为该容器正尝试使用超出其限制的 CPU 资源。
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<!--
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{{< note >}}
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Another possible explanation for the CPU use being below 1.0 is that the Node might not have
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enough CPU resources available. Recall that the prerequisites for this exercise require each of
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your Nodes to have at least 1 CPU. If your Container runs on a Node that has only 1 CPU, the Container
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cannot use more than 1 CPU regardless of the CPU limit specified for the Container.
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{{< /note >}}
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-->
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{{< note >}}
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CPU 使用率低于1.0的另一种可能的解释是,节点可能没有足够的 CPU 资源可用。回想一下,此练习的先决条件需要
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您的节点至少具有 1 个 CPU。如果您的容器在只有 1 个 CPU 的节点上运行,则容器无论为容器指定的 CPU 限制如何,都不能使用超过 1 个 CPU。
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{{< /note >}}
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<!--
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## CPU units
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The CPU resource is measured in *CPU* units. One CPU, in Kubernetes, is equivalent to:
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* 1 AWS vCPU
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* 1 GCP Core
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* 1 Azure vCore
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* 1 Hyperthread on a bare-metal Intel processor with Hyperthreading
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-->
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## CPU 单元
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CPU 资源以 *CPU* 单位度量。Kubernetes中的一个 CPU 等同于:
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* 1 个 AWS vCPU
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* 1 个 GCP核心
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* 1 个 Azure vCore
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* 1 个具有超线程功能的裸机英特尔处理器上的超线程
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<!--
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Fractional values are allowed. A Container that requests 0.5 CPU is guaranteed half as much
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CPU as a Container that requests 1 CPU. You can use the suffix m to mean milli. For example
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100m CPU, 100 milliCPU, and 0.1 CPU are all the same. Precision finer than 1m is not allowed.
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CPU is always requested as an absolute quantity, never as a relative quantity; 0.1 is the same
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amount of CPU on a single-core, dual-core, or 48-core machine.
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Delete your Pod:
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-->
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允许使用小数值。要求 0.5 CPU 的容器保证一半 CPU 作为请求 1 个 CPU 的容器。
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您可以使用后缀 m 表示毫。例如 100m CPU,100 milliCPU 和 0.1 CPU 都相同。
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精度不能超过 1m。
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始终要求 CPU 是绝对数量,而不是相对数量。0.1 在单核,双核或 48 核计算机上的 CPU 数量值是一样的。
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```shell
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kubectl delete pod cpu-demo --namespace=cpu-example
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```
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<!--
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## Specify a CPU request that is too big for your Nodes
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CPU requests and limits are associated with Containers, but it is useful to think
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of a Pod as having a CPU request and limit. The CPU request for a Pod is the sum
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of the CPU requests for all the Containers in the Pod. Likewise, the CPU limit for
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a Pod is the sum of the CPU limits for all the Containers in the Pod.
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Pod scheduling is based on requests. A Pod is scheduled to run on a Node only if
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the Node has enough CPU resources available to satisfy the Pod CPU request.
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In this exercise, you create a Pod that has a CPU request so big that it exceeds
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the capacity of any Node in your cluster. Here is the configuration file for a Pod
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that has one Container. The Container requests 100 CPU, which is likely to exceed the
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capacity of any Node in your cluster.
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{{< codenew file="pods/resource/cpu-request-limit-2.yaml" >}}
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Create the Pod:
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-->
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## 对您的节点而言,设置一个 CPU 过大的请求
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CPU 请求和限制与容器相关联,但是我们可以考虑一下 CPU 对应 Pod 的请求和限制这样的场景:Pod 对 CPU 使用量的请求等于 Pod 中所有容器的请求数量。
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同样,CPU 对 Pod 请求资源的限制等于 Pod 中所有容器的请求的 CPU 资源限制数。
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Pod 调度基于请求。仅在以下情况下,Pod 将会在节点上运行:节点具有足够的 CPU 资源可用于满足 Pod CPU 请求。
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在本练习中,您将创建一个 Pod,该 Pod 的 CPU 请求对于集群中任何节点的容量而言都会过大。
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这是 Pod 的配置文件,Pod 中有一个容器。容器请求 100 个 CPU,这可能会超出集群中任何节点的容量。
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{{< codenew file="pods/resource/cpu-request-limit-2.yaml" >}}
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使用如下命令创建该 Pod
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```shell
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kubectl apply -f https://k8s.io/examples/pods/resource/cpu-request-limit-2.yaml --namespace=cpu-example
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```
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<!--
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View the Pod status:
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-->
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查看该 Pod 的状态
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```shell
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kubectl get pod cpu-demo-2 --namespace=cpu-example
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```
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<!--
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The output shows that the Pod status is Pending. That is, the Pod has not been
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scheduled to run on any Node, and it will remain in the Pending state indefinitely:
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-->
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输出显示 Pod 状态为Pending。也就是说,尚未将 Pod 调度到任何节点上运行,
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并且 Pod 将无限期地处于Pending状态:
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```shell
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kubectl get pod cpu-demo-2 --namespace=cpu-example
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```
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```
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NAME READY STATUS RESTARTS AGE
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cpu-demo-2 0/1 Pending 0 7m
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```
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<!--
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View detailed information about the Pod, including events:
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-->
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查看有关 Pod 的详细信息,包括事件如下:
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```shell
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kubectl describe pod cpu-demo-2 --namespace=cpu-example
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```
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<!--
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The output shows that the Container cannot be scheduled because of insufficient
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CPU resources on the Nodes:
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-->
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输出显示由于节点上的 CPU 资源不足,无法调度容器
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```
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Events:
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Reason Message
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------ -------
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FailedScheduling No nodes are available that match all of the following predicates:: Insufficient cpu (3).
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```
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<!--
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Delete your Pod:
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-->
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删除您的 Pod
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```shell
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kubectl delete pod cpu-demo-2 --namespace=cpu-example
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```
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<!--
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## If you do not specify a CPU limit
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If you do not specify a CPU limit for a Container, then one of these situations applies:
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* The Container has no upper bound on the CPU resources it can use. The Container
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could use all of the CPU resources available on the Node where it is running.
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* The Container is running in a namespace that has a default CPU limit, and the
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Container is automatically assigned the default limit. Cluster administrators can use a
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[LimitRange](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#limitrange-v1-core/)
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to specify a default value for the CPU limit.
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-->
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## 如果没有指定 CPU 限制
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如果您没有为容器指定 CPU 限制,则适用以下情况之一:
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* 容器在可以使用的 CPU 资源上没有上限。容器可以使用运行该节点的所有可用 CPU 资源。
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* 容器在具有默认 CPU 限制的命名空间中运行,并且系统会自动为容器分配默认限制。集群管理员可以使用
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[LimitRange](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#limitrange-v1-core/)
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指定 CPU 限制的默认值。
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<!--
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## Motivation for CPU requests and limits
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By configuring the CPU requests and limits of the Containers that run in your
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cluster, you can make efficient use of the CPU resources available on your cluster
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Nodes. By keeping a Pod CPU request low, you give the Pod a good chance of being
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scheduled. By having a CPU limit that is greater than the CPU request, you accomplish two things:
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* The Pod can have bursts of activity where it makes use of CPU resources that happen to be available.
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* The amount of CPU resources a Pod can use during a burst is limited to some reasonable amount.
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-->
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## CPU 请求和限制的初衷
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通过配置 CPU 请求和在您的容器中运行的容器的限制
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集群,您可以有效利用集群上可用的 CPU 资源
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节点。通过将 Pod CPU 请求保持在较低水平,可以使 Pod 成为
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预定的。通过使 CPU 限制大于 CPU 请求,您可以完成两件事:
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* Pod 可能会有大量活动,它利用恰好可用的 CPU 资源。
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* Pod 在突发期间可以使用的 CPU 资源数量被限制为合理的数量。
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<!--
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## Clean up
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Delete your namespace:
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-->
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## 清理
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删除名称空间:
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```shell
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kubectl delete namespace cpu-example
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```
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{{% /capture %}}
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{{% capture whatsnext %}}
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<!--
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### For app developers
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* [Assign Memory Resources to Containers and Pods](/docs/tasks/configure-pod-container/assign-memory-resource/)
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* [Configure Quality of Service for Pods](/docs/tasks/configure-pod-container/quality-service-pod/)
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-->
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### 针对应用开发者
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* [将内存资源分配给容器和 Pod](/docs/tasks/configure-pod-container/assign-memory-resource/)
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* [配置 Pod 服务质量](/docs/tasks/configure-pod-container/quality-service-pod/)
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<!--
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### For cluster administrators
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* [Configure Default Memory Requests and Limits for a Namespace](/docs/tasks/administer-cluster/memory-default-namespace/)
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* [Configure Default CPU Requests and Limits for a Namespace](/docs/tasks/administer-cluster/cpu-default-namespace/)
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* [Configure Minimum and Maximum Memory Constraints for a Namespace](/docs/tasks/administer-cluster/memory-constraint-namespace/)
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* [Configure Minimum and Maximum CPU Constraints for a Namespace](/docs/tasks/administer-cluster/cpu-constraint-namespace/)
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* [Configure Memory and CPU Quotas for a Namespace](/docs/tasks/administer-cluster/quota-memory-cpu-namespace/)
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* [Configure a Pod Quota for a Namespace](/docs/tasks/administer-cluster/quota-pod-namespace/)
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* [Configure Quotas for API Objects](/docs/tasks/administer-cluster/quota-api-object/)
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-->
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### 针对集群管理员
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* [配置名称空间的默认内存请求和限制](/docs/tasks/administer-cluster/memory-default-namespace/)
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* [为命名空间配置默认的 CPU 请求和限制](/docs/tasks/administer-cluster/cpu-default-namespace/)
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* [为命名空间配置最小和最大内存限制](/docs/tasks/administer-cluster/memory-constraint-namespace/)
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* [为命名空间配置最小和最大 CPU 约束](/docs/tasks/administer-cluster/cpu-constraint-namespace/)
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* [为命名空间配置内存和 CPU 配额](/docs/tasks/administer-cluster/quota-memory-cpu-namespace/)
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* [为命名空间配置 Pod 配额](/docs/tasks/administer-cluster/quota-pod-namespace/)
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* [配置 API 对象的配额](/docs/tasks/administer-cluster/quota-api-object/)
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{{% /capture %}}
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|