All Products
Document Center

Container Service for Kubernetes:Add free worker nodes to a node pool

Last Updated:May 30, 2024

Free nodes exist in clusters created before the node pool feature was released. If you no longer need free nodes, you can release the Elastic Compute Service (ECS) instances that are used to deploy the nodes. If you want to retain free nodes, we recommend that you add them to node pools. This way, you can manage the nodes in groups.

Step 1: Create and scale out a node pool

Before you add free nodes to a node pool, you must create and scale out a node pool. Make sure that the expected number of nodes in the node pool is equal to the number of free nodes you want to add and the node pool uses the same node configurations as the free nodes.

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

  2. On the Clusters page, click the name of the cluster that you want to manage and choose Nodes > Node Pools in the left-side navigation pane.

  3. In the upper-right corner of the Node Pools page, click Create Node Pool. Set the node pool parameters and then click Confirm Order.

    For more information about node pool parameters, see Create a node pool.

Step 2: Remove free nodes from the cluster

You can remove free nodes in the Container Service for Kubernetes (ACK) console. When you remove free nodes, do not select Release ECS Instance in the Remove Node dialog box. For more information, see Remove a node.

Step 3: Add existing nodes to the cluster

After you remove nodes from the cluster, you can re-add the corresponding ECS instances to the cluster. For more information about the procedure and precautions, see Add existing ECS instances to an ACK cluster.


  • ACK provides managed node pools that feature automated O&M to help simplify your O&M work. Managed node pools provide features such as auto node repair, auto kubelet update, and auto Common Vulnerabilities and Exposures (CVE) patching. For more information, see Overview of managed node pools.

  • ACK allows you to scale a node pool by modifying the expected number of nodes in the node pool. You can scale out node pools to meet the requirements of business development and scale in node pools to reduce resource costs. For more information, see Scale a node pool.

  • For more information about the comparison of different container runtimes, such as conatinerd and Docker, see Comparison of Docker, containerd, and Sandboxed-Container .

  • Outdated Kubernetes versions may have security and stability issues. We recommend that you update the Kubernetes version of your ACK cluster to the latest version. For more information, see Update an ACK cluster.

  • For more information about how to release ECS instances, see Release an instance.