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Container Service for Kubernetes:Resize master nodes in an ACK dedicated cluster

Last Updated:Jun 23, 2026

In ACK dedicated clusters, master nodes require manual administration. As your cluster scales, these nodes may have insufficient or excess resources. This topic describes how to change master node instance specifications.

Prerequisites

Before you begin, ensure that you have:

Usage notes

Important

This operation may involve unexpected risks. Back up your data before proceeding.

  • Applies to pay-as-you-go master nodes. See Overview of instance configuration changes for other billing methods or alternative scaling approaches.

  • Resource scaling requires a node reboot.

  • Schedule during off-peak hours to minimize business impact.

  • Modify multiple master nodes one at a time to maintain cluster availability. Parallel changes may disrupt the API server.

  • OS replacement is not supported on master nodes.

Change the instance type of a master node

  1. Log on to the ACK console. In the left-side navigation pane, click Clusters.

  2. On the Clusters page, click the target cluster name. In the left-side navigation pane, choose Nodes > Nodes.

  3. Locate the master node whose instance type you want to change, click its instance ID to open the Instance Details tab, and view the current instance specifications. Locate the target master node and click its instance ID to open the Instance Details tab.

  4. In the Configuration Information section, click Change next to the instance type.

  5. Select an instance type, confirm the estimated cost, and click Stop Instances and Proceed. See Choose ECS specifications to create master nodes for sizing recommendations.

  6. In the Stop Instance dialog box, set Stopped By and click Confirm. See Stop an instance.

  7. After the change completes, click Start Instance And Return. In the Start Instance dialog box, click OK. Wait for the node to rejoin the cluster and enter the Ready state.