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

Background information

Master nodes cannot be scaled out in an ACK cluster.


  1. Log on to the Container Service for Kubernetes (ACK) console.
  2. In the left-side navigation pane, click Clusters.
  3. On the Clusters page, find the cluster that you want to expand and choose More > Expand in the Actions column.
  4. On the Expand page, set the scale-out parameters.
    Parameter Description
    Region This parameter is automatically set to the region where the cluster is deployed.
    Container Runtime This parameter is automatically set to Docker 19.03.5.
    VPC Set the network for the nodes. You can select a virtual private cloud (VPC) from the drop-down list. If no VPC is available, click Create VPC to create one. For more information, see Create a VPC.
    VSwitch Set the vSwitches.

    You can select up to three vSwitches that are deployed in different zones. If no vSwitch is available, click Create VSwitch to create one. For more information, see Create a VSwitch.

    Billing Method The pay-as-you-go and subscription billing methods are supported. For more information, see Billing method overview. If you select the subscription billing method,
    • the Duration parameter is required. You can select 1, 2, 3, or 6 months. If you require a longer duration, you can select 1 to 5 years.
    • Specify whether to enable Auto Renewal.
    Instance Type You can select one or more instance types. For more information, see Instance families.
    Selected Types The selected instance types are displayed.
    System Disk
    Enhanced SSDs, SSDs, and ultra disks are supported.
    Note You can select Enable Backup to back up disk data.
    Mount Data Disk

    Enhanced SSDs, SSDs, and ultra disks are supported. You can enable disk encryption and backup when you mount data disks.

    Nodes to Add The number of nodes to be added to the cluster. You can add up to 100 nodes to a cluster under the current account. You can add up to 500 nodes at a time.
    Logon Type
    • Set the key pair.
      • Key Pair: Select an SSH key pair from the drop-down list.
      • create a key pair: Create an SSH key pair if no SSH key pair is available. For more information about how to create an SSH key pair, see Create an SSH key pair. After the key pair is created, set it as the credential that is used to log on to the ACK cluster.
    • Password:
      • Password: Enter the password that is used to log on to the nodes.
      • Confirm Password: Enter the password again.
    ECS Label You can add labels to the ECS instances.
    Node Label You can add labels to the nodes of the cluster.
    Taints You can add taints to all worker nodes in the cluster.
    Custom Image
    You can select a custom image for the nodes to be added. After you select a custom image, the nodes to be added are deployed based on the image. For more information about how to create a custom image, see Create a Kubernetes cluster by using a custom image.
    • Only custom images based on CentOS 7.x and Alibaba Cloud Linux 2.x are supported. Before you use a custom image to deploy the nodes, you must add the nodes to the cluster in manual mode. For more information about how to add nodes to a cluster in Manual mode, see Add ECS instances in manual mode.
    • This feature is available to only users in the whitelist. If you are not in the whitelist, submit a ticket.
    RDS whitelist Set the Relational Database Service (RDS) whitelist. Add the IP addresses of the nodes in the ACK cluster to the RDS whitelist.
    Note To enable an RDS instance to access an ACK cluster, you must deploy the RDS instance in the same VPC as the ACK cluster.
    User Data For more information, see Prepare user data.
  5. Click Confirm.
    On the Node Pools page, if the Status column shows Scaling for the node pool, it indicates that the node pool is being scaled out. After the node pool is scaled out, the Status column shows Active for the node pool.

What to do next

Click Details in the Actions column. On the Nodes tab, you can view information about the nodes that are added to the node pool.