131 lines
5.7 KiB
Markdown
131 lines
5.7 KiB
Markdown
---
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title: 资源指标管道
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content_type: concept
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---
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<!--
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reviewers:
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- fgrzadkowski
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- piosz
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title: Resource metrics pipeline
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content_type: concept
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-->
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<!-- overview -->
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<!--
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Resource usage metrics, such as container CPU and memory usage,
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are available in Kubernetes through the Metrics API. These metrics can be either accessed directly
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by user, for example by using `kubectl top` command, or used by a controller in the cluster, e.g.
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Horizontal Pod Autoscaler, to make decisions.
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-->
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资源使用指标，例如容器 CPU 和内存使用率，可通过 Metrics API 在 Kubernetes 中获得。
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这些指标可以直接被用户访问，比如使用 `kubectl top` 命令行，或者这些指标由集群中的控制器使用，
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例如，Horizontal Pod Autoscaler，使用这些指标来做决策。
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<!-- body -->
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<!--
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## The Metrics API
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Through the Metrics API you can get the amount of resource currently used
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by a given node or a given pod. This API doesn't store the metric values,
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so it's not possible for example to get the amount of resources used by a
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given node 10 minutes ago.
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-->
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## Metrics API {#the-metrics-api}
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通过 Metrics API，你可以获得指定节点或 Pod 当前使用的资源量。
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此 API 不存储指标值，因此想要获取某个指定节点 10 分钟前的资源使用量是不可能的。
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<!--
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The API is no different from any other API:
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-->
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此 API 与其他 API 没有区别：
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<!--
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- it is discoverable through the same endpoint as the other Kubernetes APIs under `/apis/metrics.k8s.io/` path
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- it offers the same security, scalability and reliability guarantees
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-->
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- 此 API 和其它 Kubernetes API 一起位于同一端点（endpoint）之下，是可发现的，
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路径为 `/apis/metrics.k8s.io/`
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- 它提供相同的安全性、可扩展性和可靠性保证
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<!--
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The API is defined in [k8s.io/metrics](https://github.com/kubernetes/metrics/blob/master/pkg/apis/metrics/v1beta1/types.go)
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repository. You can find more information about the API there.
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-->
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Metrics API 在 [k8s.io/metrics](https://github.com/kubernetes/metrics/blob/master/pkg/apis/metrics/v1beta1/types.go)
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仓库中定义。你可以在那里找到有关 Metrics API 的更多信息。
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<!--
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The API requires metrics server to be deployed in the cluster. Otherwise it will be not available.
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-->
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{{< note >}}
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Metrics API 需要在集群中部署 Metrics Server。否则它将不可用。
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{{< /note >}}
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<!--
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## Measuring Resource Usage
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### CPU
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CPU is reported as the average usage, in [CPU cores](/docs/concepts/configuration/manage-compute-resources-container/#meaning-of-cpu), over a period of time. This value is derived by taking a rate over a cumulative CPU counter provided by the kernel (in both Linux and Windows kernels). The kubelet chooses the window for the rate calculation.
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-->
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## 度量资源用量 {#measuring-resource-usage}
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### CPU
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CPU 用量按其一段时间内的平均值统计，单位为
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[CPU 核](/zh/docs/concepts/configuration/manage-resources-containers/#meaning-of-cpu)。
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此度量值通过在内核（包括 Linux 和 Windows）提供的累积 CPU 计数器乘以一个系数得到。
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`kubelet` 组件负责选择计算系数所使用的窗口大小。
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### 内存 {#memory}
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内存用量按工作集（Working Set）的大小字节数统计，其数值为收集度量值的那一刻的内存用量。
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如果一切都很理想化，“工作集” 是任务在使用的内存总量，该内存是不可以在内存压力较大
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的情况下被释放的。
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不过，具体的工作集计算方式取决于宿主 OS，有很大不同，且通常都大量使用启发式
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规则来给出一个估计值。
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其中包含所有匿名内存使用（没有后台文件提供存储者），因为 Kubernetes 不支持交换分区。
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度量值通常包含一些高速缓存（有后台文件提供存储）内存，因为宿主操作系统并不是总能
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回收这些页面。
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<!--
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## Metrics Server
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[Metrics Server](https://github.com/kubernetes-incubator/metrics-server) is a cluster-wide aggregator of resource usage data.
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Starting from Kubernetes 1.8 it's deployed by default in clusters created by `kube-up.sh` script
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as a Deployment object. If you use a different Kubernetes setup mechanism you can deploy it using the provided
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[deployment yamls](https://github.com/kubernetes-incubator/metrics-server/tree/master/deploy).
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It's supported in Kubernetes 1.7+ (see details below).
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-->
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## Metrics 服务器 {#metrics-server}
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[Metrics 服务器](https://github.com/kubernetes-incubator/metrics-server)是集群范围资源使用数据的聚合器。
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在由 `kube-up.sh` 脚本创建的集群中默认会以 Deployment 的形式被部署。
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如果你使用其他 Kubernetes 安装方法，则可以使用提供的
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[deployment yamls](https://github.com/kubernetes-incubator/metrics-server/tree/master/deploy)
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来部署。
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<!--
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Metric server collects metrics from the Summary API, exposed by [Kubelet](/docs/admin/kubelet/) on each node.
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-->
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Metric server 从每个节点上的 [Kubelet](/zh/docs/reference/command-line-tools-reference/kubelet/)
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公开的 Summary API 中采集指标信息。
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<!--
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Metrics Server registered in the main API server through
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[Kubernetes aggregator](/docs/concepts/api-extension/apiserver-aggregation/),
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which was introduced in Kubernetes 1.7.
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-->
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Metrics 服务器通过
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[Kubernetes 聚合器](/zh/docs/concepts/extend-kubernetes/api-extension/apiserver-aggregation/)
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注册到主 API 服务器。
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<!--
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Learn more about the metrics server in [the design doc](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/metrics-server.md).
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-->
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在[设计文档](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/metrics-server.md)中可以了解到有关 Metrics 服务器的更多信息。
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