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Volcengine Kubernetes Engine

Monitoring add-ons

metrics-server

The metrics-server is a core cluster monitoring add-on. It provides container resource monitoring metrics for the cluster auto-scaling feature. This topic describes the functionality, core resource forms, service discovery types, and installation and upgrade methods of this add-on.

Add-on overview

The metrics-server is a system add-on required for the normal operation of a VKE cluster and is installed by default when you create a cluster. After the add-on is installed in a cluster, the system will create the following Kubernetes resources under the kube-system namespace.

Resource name	Resource type	Resource description
metrics-server	Deployment	The core workload of the add-on. It is used to run the logic for cluster metric collection and aggregation.
metrics-server	Service	The add-on service. It provides a stable internal access endpoint for the add-on.

tip

The preceding table only lists the main resources of the add-on, as well as resources that may be used when the add-on or the corresponding feature is configured. This helps you understand the main components of this add-on. Other resources, such as ConfigMap and Secret, related to the add-on are not described here. You should refer to the actual resources in the cluster.

Add-on versions

For information about the historical release records of the add-on, as well as new features and optimization descriptions for each version, see Add-on release records.

Install the add-on

In the left navigation pane, click Cluster. Click the target cluster name to go to the management page of this cluster.

In the left navigation bar of the cluster management page, click Addons. On the page that appears, click the Monitoring tab.

Move the pointer over the add-on card, click Deploy, and configure the add-on parameters.

Parameter	Description
Deployment method	The deployment method of the add-on. This parameter is fixed and cannot be modified.
Deployment mode	This parameter is displayed only for clusters for which the vci-virtual-kubelet add-on is installed. You can deploy the add-on on the following two types of nodes. Elastic Compute Service deployment: deploys the add-on on ECS nodes in the cluster. Volcengine Container Instance deployment: Deploys the add-on on a VCI with 2 vCPUs and 4 GiB specifications. This will incur extra fees. For a detailed description of fees, see VCI service billing.
Node Label Selector	This parameter can be specified only when the Deployment form parameter is set to Elastic Compute Service deployment. After you enable this feature, you can specify node labels, and the core workloads of the add-on will be scheduled onto nodes with the specified labels. warning You can specify this parameter only for the metrics-server add-on of v0.7.1-vke.3 and later.
Pod scheduling based on taints and tolerations	This parameter can be specified only when the Deployment form parameter is set to Elastic Compute Service deployment. After you enable this feature, you can set taint toleration conditions. The core workloads of the add-on can be scheduled onto nodes with specified taints. warning You can specify this parameter only for the metrics-server add-on of v0.7.1-vke.3 and later.
Resource configuration	Configure add-on resources, including the CPU request, CPU limit, memory request, and memory limit. warning You can specify this parameter only for the metrics-server add-on of v0.7.1-vke.3 and later.

Click Confirm to finish configuration.

Upgrading add-ons

New versions of the add-on are released at irregular intervals to provide new features or fix known issues. When the add-on card displays that a new version is available, we recommend upgrading the add-on promptly. To ensure a smooth service transition, perform the upgrade during off-peak hours whenever possible. For upgrade procedures and considerations, see Upgrading add-ons.

Monitoring and alerting

Add-on observability

The stability and performance of the metrics-server add-on directly affect the proper functioning and overall effectiveness of your cluster. We recommend enabling add-on observability in your cluster to monitor add-on health in real time. For details, see VKE observability.

Configuring alerts

VKE provides comprehensive cluster monitoring and alerting capabilities based on VMP. You can quickly create alert rule groups by using preset templates or configure custom alert rules by using PromQL statements based on your business requirements. You can also export preset templates in YAML format, adjust the rules, and save them as custom alert templates for reuse across multiple clusters. For details, see the following topics:

Configuring alerts through preset templates

Configuring alerts based on custom templates

Configuring alerts through custom alert rules

Preset alert templates are provided by the system based on common O&M scenarios. They are applicable to building an alert system for the first time or quickly supplementing basic monitoring items. This helps you promptly detect insufficient resources or abnormal operation of add-ons. For details about the alert rules in preset alert templates, see Preset alert templates.