Managing Node Labels

Node Label Usage Scenario

Node labels are mainly used in the following scenarios:

Node management: Node labels are used to classify nodes.
Affinity and anti-affinity between a workload and node:
- Different workloads have different resource requirements such as CPU, memory, and I/O. If a workload consumes too many resources in a cluster, other workloads in the same cluster may fail to run properly. In this case, you are advised to add different labels to nodes. When deploying a workload, you can select nodes with specified labels for affinity deployment to ensure the normal operation of the system. Otherwise, node anti-affinity deployment can be used.
- A system can be divided into multiple modules. Each module consists of multiple microservices. To ensure efficient O&M, you can add a module label to each node so that each module can be deployed on the corresponding node. In this way, modules do not interfere with each other and microservices can be easily maintained on their nodes.

Inherent Label of a Node

After a node is created, some fixed labels exist and cannot be deleted. For details about these labels, see Table 1.

Do not manually change the inherent labels that are automatically added to a node. If the manually changed value conflicts with the system value, the system value is used.

**Table 1** Inherent labels of a node
Key	Description
New: topology.kubernetes.io/region Old: failure-domain.beta.kubernetes.io/region	Region where the node is located
New: topology.kubernetes.io/zone Old: failure-domain.beta.kubernetes.io/zone	AZ where the node is located
New: node.kubernetes.io/baremetal Old: failure-domain.beta.kubernetes.io/is-baremetal	Whether the node is a bare metal node false indicates that the node is not a bare metal node.
node.kubernetes.io/instance-type	Node specifications
kubernetes.io/arch	Node processor architecture
kubernetes.io/hostname	Node name
kubernetes.io/os	OS type
node.kubernetes.io/subnetid	ID of the subnet where the node is located.
os.architecture	Node processor architecture For example, amd64 indicates a AMD64-bit processor.
os.name	Node OS name
os.version	Node OS kernel version
node.kubernetes.io/container-engine	Container engine used by the node.
accelerator	GPU node labels.
cce.cloud.com/cce-nodepool	The dedicated label of a node in a node pool.

Adding or Deleting a Node Label

Log in to the CCE console.
Click the cluster name, access the cluster details page, and choose Nodes in the navigation pane. On the page displayed, select a node and click Labels and Taints above the list.
In the displayed dialog box, click Add Operation under Batch Operation, and then choose Add/Update or Delete.

Enter the key and value of the label to be added or deleted, and click OK.

For example, the key is deploy_qa and the value is true, indicating that the node is used to deploy the QA (test) environment.
After the label is added, check the added label in node data.