Create and manage LINGJUN node pools

Before you create

• By default, LINGJUN node pools store container runtime data on the system disk. Ensure you reserve enough space for the container runtime directory. Insufficient disk space can lead to pod evictions or node failures.

• New LINGJUN node pools default to using the Terway exclusive ENI mode for VPC network communication. Confirm that the maximum number of pods per node meets your business requirements.

• Nodes in a LINGJUN node pool carry the taint node-role.alibabacloud.com/lingjun: NoSchedule by default. This prevents system components (other than DaemonSets) from being scheduled to LINGJUN nodes and consuming resources.

  If a pod needs to be scheduled to a LINGJUN node, you can add a toleration for this taint to the pod. This ensures that only specific workloads are scheduled to LINGJUN nodes. You can also replace it with a custom taint to achieve the same effect based on your business needs.

  You can remove the taint after ensuring your components meet the minimum version requirements. However, if you remove the taint, system components or other workloads may be scheduled to the LINGJUN nodes, consuming expensive GPU node resources.

• For the complete list of default labels applied to the node pool, see the Node labels configuration description below. Do not delete these default labels.

Procedure

1. On the Clusters page, click the name of the target cluster. In the left-side navigation pane, choose Nodes > Node Pools.

2. Click ... > Create Lingjun Node Pool and follow the on-screen instructions to create the LINGJUN node pool.

   After the node pool is created, you can modify some configuration items by editing the node pool. In the table below, Modifiable indicates whether a configuration item can be changed after creation.

   Configuration details

   • Basic configuration

     Parameter	Description	Modifiable
     Node Pool Name	A custom name for the node pool.	Yes
     Region	The region of the current cluster is selected by default and cannot be changed.	No
     Configure Managed Node Pool	Whitelisted feature Enable managed node pools to use ACK's automated O&M capabilities.	Yes
     Container Runtime	Only containerd is supported.	No

   • Lingjun Resources

     Parameter	Description	Modifiable
     Lingjun Cluster	You can select a LINGJUN cluster of the Lite type that is in the same VPC as the ACK cluster.	No
     Lingjun Group	You can select a LINGJUN group that is in the same VPC as the LINGJUN node pool and is not associated with any other LINGJUN node pool.	No

   • Volumes

     Custom data disk configuration is a whitelisted feature. To enable it, contact the Container Service team through your PDSA.

     Important

     • During a node pool upgrade, if nodes have different storage configurations, they are initialized according to each node's actual configuration.

     • To ensure stability, reserve sufficient space for the container runtime directory. Local storage carries a risk of data loss. We strongly recommend mounting a cloud disk for the container runtime directory.

     Parameter	Description	Modifiable
     System Disk	The cloud disk system disk configuration for nodes in the current LINGJUN group. This is not displayed for nodes with local system disks. If Configure local disk mounting for the container runtime directory is not selected, the container runtime directory defaults to the system disk. Important If container runtime data is stored on the system disk, insufficient disk space can lead to pod evictions or node failures. For stability, ensure you reserve ample space on the system disk or configure a separate data disk for the container runtime. See Node disk space is insufficient due to DiskPressure for solutions to insufficient node disk space.	N/A
     Data Disk	The local data disk used by the LINGJUN node. If you select Configure local disk mounting for the container runtime directory, the local disk will be mounted to the directories used by the container runtime, including /var/lib/container, /var/lib/containerd, /var/lib/kubelet, and /var/log/pods. You can configure Initialization Settings: Choose a file system format (ext4 or xfs). This only affects unformatted local disks. Important The mount directory must be empty. If you mount to a non-empty directory, the original files become inaccessible. Local storage carries a risk of data loss. We strongly recommend using a cloud disk to mount the container runtime directory. When this feature is enabled, do not simultaneously configure the container runtime directory by using ACK Pre-defined Custom Data or LINGJUN custom data (UserData), as this may cause issues. When a LINGJUN node undergoes offline maintenance (replacement with a standby machine), data on the local disk is lost. This clears container runtime information for kubelet and containerd, causing the node to enter an abnormal state. After maintenance is complete, you must manually remove the node from the node pool and re-add it using Add Existing Node.	Yes

   • Advanced Options (Optional)

     Parameter	Description	Modifiable
     Taints	Add key-value taints to nodes. A valid taint key includes an optional prefix and a name. If a prefix is specified, separate it from the name with a forward slash (/). Expand to view details Key: The name must be 1–63 characters long, start and end with a letter, digit, or character [a-z0-9A-Z], and can contain letters, digits, hyphens (-), underscores (_), and periods (.). If a prefix is specified, it must be a DNS subdomain, meaning a series of DNS labels separated by periods (.), up to 253 characters long, ending with a forward slash (/). Value: Can be empty, up to 63 characters long, must start and end with a letter, digit, or character [a-z0-9A-Z], and can contain letters, digits, hyphens (-), underscores (_), and periods (.). Effect: NoSchedule: Prevents new pods that do not tolerate this taint from being scheduled to the node, but does not affect pods already running. NoExecute: Prevents new pods that do not tolerate this taint from being scheduled to the node and evicts any running pods that do not tolerate this taint. PreferNoSchedule: ACK tries to avoid scheduling pods to nodes with taints they cannot tolerate, but does not enforce this strictly.	Yes
     Node Labels	Important When you create a LINGJUN node pool, ACK automatically adds a label to enable exclusive ENI mode. Do not delete this label after creation. Do not delete the default labels that are automatically added to the LINGJUN node pool: service.alibabacloud.com/exclude-node alibabacloud.com/lingjun-worker alibabacloud.com/lingjun-hpnzone alibabacloud.com/lingjun-zoneid alibabacloud.com/lingjun-network-type: vpd alibabacloud.com/lingjun-machine-type k8s.aliyun.com/exclusive-mode-eni-type: eniOnly Add key-value labels to nodes. A valid key includes an optional prefix and a name. If a prefix is specified, separate it from the name with a forward slash (/). Expand to view details Key: The name must be 1–63 characters long, start and end with an alphanumeric character [a-z0-9A-Z], and can contain letters, digits, hyphens (-), underscores (_), and periods (.). If a prefix is specified, it must be a DNS subdomain, meaning a series of DNS labels separated by periods (.), up to 253 characters long, ending with a forward slash (/). The following prefixes are reserved by Kubernetes core components and cannot be specified kubernetes.io/ k8s.io/ Prefixes ending with kubernetes.io/ or k8s.io/. For example, test.kubernetes.io/. Exceptions: kubelet.kubernetes.io/ node.kubernetes.io Prefixes ending with kubelet.kubernetes.io/. Prefixes ending with node.kubernetes.io. Value: Can be empty, up to 63 characters long, must start and end with an alphanumeric character [a-z0-9A-Z], and can contain letters, digits, hyphens (-), underscores (_), and periods (.).	Yes
     Container Image Acceleration	Supported only for containerd runtime version 1.6.34 or later. Newly added nodes automatically detect whether container images support on-demand loading. If supported, containers start faster by default using on-demand loading, reducing application startup time. For details, see Use on-demand loading to accelerate container startup.	Yes
     Custom Node Name	Whitelisted feature, not applicable to non-LINGJUN node pools Description: Synchronizes the Hostname of a LINGJUN node directly as the NodeName. Example: If the instance Hostname is test, the node's NodeName is test.	No
     Pre-defined Custom Data	Before nodes join the cluster, run the specified instance pre-user User-Data script. Example: If the pre-user data is touch /tmp/pre-script, the combined script execution order on the node is as follows. #!/bin/bash # Input instance pre-user data executes here touch /tmp/pre-script # ACK node initialization script executes here	Yes
     User Data	After nodes join the cluster, run the specified instance user User-Data script. Example: If the instance user data is touch /tmp/post-script, the combined script execution order on the node is as follows. #!/bin/bash # ACK node initialization script executes here # Input instance user data executes here touch /tmp/post-script Successful cluster creation or node scale-out does not guarantee successful execution of the instance user script. Log on to the node and run grep cloud-init /var/log/messages to view execution logs.	Yes

Prerequisites

• The nodes to be added must already be in the LINGJUN group associated with this node pool and must not be in another node pool.

• The LINGJUN node's OperatingState must be "Using".

Procedure

1. On the ACK Clusters page, click the name of your cluster. In the left navigation pane, click Nodes > Node Pools.

2. On the Node Pools page, click ⋮ > Add Existing Node and configure the following parameters as prompted:

   • Add Existing Lingjun Node: Select the instances to add from the instance list. Select Show Unavailable Instances to view instances that are currently unavailable.

   • Data Disk: Select how to mount the data disk.

     Only available if the custom data disk configuration whitelist is enabled.

     • Configure by Node Pool: Initializes and mounts the data disk by using the node pool's preset data disk configuration.

       If the node pool has no preset data disk configuration, the node's original configuration is retained.

     • No Initialization: Does not initialize the data disk, retaining its original configuration.

       Important

       • If storage configurations differ across nodes, the system initializes their data disks based on each node's actual storage configuration during a node pool upgrade, rather than using a uniform configuration.

       • When you use the node pool configuration, the mount directory must be empty. If you mount to a non-empty directory, the original files become inaccessible.

   After the nodes are added, ACK automatically adds the following tags to the LINGJUN node instances, which you can view in the Intelligent Computing LINGJUN Service console:

   • ack.aliyun.com: The ID of the ACK Managed Cluster Pro Edition that manages the node.

   • ack.alibabacloud.com/nodepool-id: The ID of the LINGJUN node pool that manages the node.

Notes

• Draining nodes:

  • If there are pods on the node, select Drain Node. The pods will be migrated to other nodes. Ensure your cluster has sufficient resources to accommodate them.

  • If your application is configured with a Pod Disruption Budget (PDB), draining may fail, which prevents the node from being removed. We recommend handling this manually beforehand.

  • If an application fails to start on another node after being drained, the removal task ignores this and continues.

  • When you remove a node in an abnormal state, do not select Drain Node, as this may cause the removal to fail.

• Node state after removal:

  Removing a LINGJUN node only removes it from the LINGJUN node pool. It does not remove the node from the LINGJUN group, nor does it automatically release the node or cancel its subscription.

  Deleting an ACK cluster or LINGJUN node pool does not release the LINGJUN node instances. The service also does not automatically scale in the nodes from the LINGJUN group. Monitor the billing status of your LINGJUN nodes to avoid extra charges.

  For other node and group management tasks, use the Intelligent Computing LINGJUN Service console.

  Removal is an asynchronous operation. You can check the progress in the node list.

Procedure

1. On the ACK Clusters page, click the name of your cluster. In the left navigation pane, click Nodes > Node Pools.

2. Click the name of the target LINGJUN node pool and remove nodes on the Nodes page.

   • Remove a single node: Locate the target node, and in the Actions column, select More > Remove.

   • Remove nodes in batches: Select the target nodes and click Batch Remove at the bottom of the page.

3. Choose whether to Drain Node. Carefully read the on-screen notes and complete the operation as prompted.

Node not ready after repair

A LINGJUN node underwent offline maintenance for a hardware issue, but after the repair is complete, its status is still Not Ready in the ACK cluster.

• Cause: During offline maintenance, the LINGJUN node's machine is replaced. Data on local disks is lost, which clears container runtime information for components like kubelet and containerd, causing the node to enter an abnormal state.

• Solution: After the repair is complete, you must manually remove the node from the node pool and then re-add it using Add Existing Node.