This topic describes how to scale out the worker nodes in a cluster in the Alibaba Cloud Container Service for Kubernetes (ACK) console.

Background information

You cannot scale out the master nodes in a cluster.


  1. Log on to the ACK console.
  2. In the left-side navigation pane, click Clusters.
  3. On the Clusters page, find the target cluster, and click Expand in the Actions column.
  4. On the Expand page, configure the scale-out settings.
    In this example, the number of worker nodes in the cluster is increased from three to five. The following table describes the required parameters.
    Parameter Description
    Cluster Name The name of the cluster.
    Region The region where the cluster is deployed.
    Container Runtime The default runtime is Docker 19.03.5.
    VPC Set the network for the nodes. You can select a Virtual Private Cloud (VPC) network from the drop-down list. If no VPC network is available, you can click Create VPC to create one. For more information, see Create a VPC network.
    VSwitch Set the VSwitches.

    Select one to three VSwitches. We recommend that you select VSwitches in different zones. If no VSwitch is available, click Create VSwitch to create one. For more information, see Create a VSwitch.

    Billing Method ACK supports the pay-as-you-go and subscription billing methods. If you select the subscription billing method:
    • You need to set the duration. Valid values: 1, 2, 3, and 6 months, 1, 2, 3, 4, and 5 years.
    • You also need to specify whether to enable Auto Renewal.
    Existing Worker Nodes The number of existing worker nodes in the cluster.
    Nodes to Add The number of nodes to be added to the cluster.
    Worker Nodes After Scaling The expected number of worker nodes in the cluster after the scale-out event.
    Instance Type You can select multiple instance types. For more information, see Instance families.
    Selected Types The selected instance types are displayed here.
    System Disk SSDs and ultra disks are supported.
    Mount Data Disk SSDs and ultra disks are supported.

    Operating System

    CentOS 7.7 is selected as the default operating system of added nodes.

    Logon Type
    • Key pair

      If you choose to use a key pair, click create a key pair to create one in the Elastic Compute Service (ECS) console. For more information, see Create an SSH key pair. After the key pair is created, set it as the credential for logging on to the cluster.

    • Password
      • Password: Enter the password.
      • Confirm Password: Enter the password again.
    Key Pair
    CloudMonitor Agent Specify whether to install the CloudMonitor agent. After the CloudMonitor agent is installed on ECS nodes, you can view monitoring information about the nodes in the CloudMonitor console.
    RDS Whitelist Set the RDS whitelist. Add the IP addresses of the scaled nodes to the RDS whitelist.
    Labels Attach labels to the nodes. Enter keys and values, and click Add.
    • Key is required. Value is optional.
    • Keys are not case-sensitive. A key must be 1 to 64 characters in length and cannot start with aliyun, http://, or https://.
    • Values are not case-sensitive. A value must be 1 to 128 characters in length and cannot start with http:// or https://.
    • The keys of labels attached to the same resource must be unique. If you add a label with a used key, the label overwrites the one using the same key.
    • You can attach up to 20 labels to each resource. If you attach more than 20 labels to a resource, all labels become invalid. You must detach unused labels for the remainings to take effect.
    Custom Image You can select a custom ECS image, which can be used to deploy all nodes in the cluster. For more information about how to create a custom image, see Create a cluster by using a custom image.
    Note This feature is only available to users in the whitelist. To use this feature, submit a ticket.
    Taints Add taints to the nodes.
    CPU Policy Set the CPU policy.
    • none: This is the default policy, which indicates that the default CPU affinity is used.
    • static: This policy allows pods with certain resource characteristics to be granted with enhanced CPU affinity and exclusivity on the node.
    User Data For more information, see Prepare user data.
  5. On the right side of the Expand page, click Submit.
  6. On the Confirm page, select the check box after you read the terms of service, and click OK.

What to do next

After the expansion is complete, go to the cluster details page. In the left-side navigation pane, click Nodes. On the Nodes page, the number of worker nodes changes from 3 to 5.

The newly created nodes are named based on custom node name.