Container Service for Kubernetes:Create a node pool

Node pool types

• Regular node pool: You can use a regular node pool to manage a set of nodes that have the same configurations, such as specifications, labels, and taints. For more information, see Node pool overview.

• Managed node pool: Managed node pools provide automated O&M features, such as automatic Common Vulnerabilities and Exposures (CVE) vulnerability patching and automatic node repair. For more information, see Overview of managed node pools.

  Note

  Only ACK Pro clusters support managed node pools.

For more information about the differences between the two types of node pools, see the Comparison between managed node pools and regular node pools section of the "Overview of managed node pools" topic.

Procedure

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

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

3. On the Node Pools page, click Create Node Pool in the upper-right corner. In the Create Node Pool dialog box, configure the parameters that are described in the following table.

   Basic settings

   Basic settings

   Parameter		Description
   Node Pool Name		Specify a node pool name.
   Managed node pool settings	Managed Node Pool	Specify whether to enable the managed node pool feature. Managed node pools are O&M-free node pools provided by ACK. Managed node pools support CVE vulnerability patching and auto recovery. They can efficiently reduce your O&M work and enhance node security. For more information, see Overview of managed node pools.
   	Auto Recovery Rule	This parameter is available after you select Managed Node Pool. After you select Restart Faulty Node, the system automatically restarts relevant components to repair nodes in the NotReady state and drains the nodes before restarting them.
   	Auto Update Rule	This parameter is available after you select Managed Node Pool. After you select Automatically Update Kubelet, the system automatically updates the kubelet when a new version is available. For more information, see Update a node pool.
   	Auto CVE Patching (OS)	This parameter is available after you select Managed Node Pool. You can configure ACK to automatically patch high-risk, medium-risk, and low-risk vulnerabilities. For more information, see Auto repair and Patch OS CVE vulnerabilities for node pools. Some patches take effect only after you restart the ECS instances. After you select Restart Nodes if Necessary to Patch CVE Vulnerabilities, the system automatically restarts nodes on demand. If you do not select this option, you need to manually restart nodes.
   	Maintenance Window	Image updates, runtime updates, and Kubernetes version updates are automatically performed during the maintenance window. For more information, see Overview of managed node pools.
   Region		By default, the region in which the cluster resides is selected. You cannot change the region.
   Confidential Computing		Note To use confidential computing, submit a ticket to apply to be added to the whitelist. This parameter is available only if you select containerd for the Container Runtime parameter. Specify whether to enable confidential computing. ACK provides a cloud-native and all-in-one confidential computing solution based on hardware encryption technologies. Confidential computing ensures data security, integrity, and confidentiality. It simplifies the development and delivery of trusted or confidential applications at lower costs. For more information, see TEE-based confidential computing.
   Container Runtime		Specify the container runtime based on the Kubernetes version. The following list describes the Kubernetes versions supported by different container runtimes: containerd: containerd is recommended for all Kubernetes versions. Sandboxed-Container: supports Kubernetes 1.24 and earlier. Docker: supports Kubernetes 1.22 and earlier. For more information, see Comparison among Docker, containerd, and Sandboxed-Container.
   Network settings	VPC	By default, the virtual private cloud (VPC) in which the cluster resides is selected. You cannot change the VPC.
   	vSwitch	When the node pool is being scaled out, new nodes are created in the zones of the selected vSwitches based on the policy that you select for the Scaling Policy parameter. You can select vSwitches in the zones that you want to use. If no vSwitch is available, click Create vSwitch to create one. For more information, see Create and manage a vSwitch.
   Auto Scaling		Specify whether to enable auto scaling. This feature provides cost-effective computing resource scaling based on business requirements and scaling policies. For more information, see Auto scaling overview. Before you enable this feature, you need to enable node auto scaling for the node pool. For more information, see Step 1: Enable node auto scaling.
   Billing Method		The following billing methods are supported for nodes in a node pool: pay-as-you-go, subscription, and preemptible instances. If you select the pay-as-you-go billing method, Elastic Compute Service (ECS) instances in the node pool are billed on a pay-as-you-go basis. You are not charged for using the node pool. If you select the subscription billing method, you must set the Duration and Auto Renewal parameters. If you select the preemptible instances billing method, you must set the following parameter at the same time. Upper Price Limit of Current Instance Spec: If the real-time market price of an instance type that you select is lower than the value of this parameter, a preemptible instance of this instance type is created. After the protection period (1 hour) ends, the system checks the spot price and resource availability of the instance type every 5 minutes. If the real-time market price exceeds your bid price or if the resource inventory is insufficient, the preemptible instance is released. ACK supports only preemptible instances with a protection period. For more information, see Overview and Best practices for preemptible instance-based node pools. Important If you change the billing method of a node pool, the change takes effect only on newly added nodes. The existing nodes in the node pool still use the original billing method. For more information about how to change the billing method of existing nodes in a node pool, see Change the billing method of an instance from pay-as-you-go to subscription. To ensure that all nodes use the same billing method, ACK does not allow you to change the billing method of a node pool from pay-as-you-go or subscription to preemptible instances, or change the billing method of a node pool from preemptible instances to pay-as-you-go or subscription.
   Instance settings	Instance Type	You can select multiple instance types. You can filter instance types by vCPU, memory, architecture, or category. Note The instance types that you select are displayed in the Selected Types section. When the node pool is scaled out, ECS instances of the instance types that you select for the Instance Type parameter are created. The scaling policy of the node pool determines which instance types are used to create new nodes during scale-out activities. Select multiple instance types to improve the success rate of node pool scale-out operations. If the node pool fails to be scaled out because the instance types are unavailable or the instances are out of stock, you can specify more instance types for the node pool. The ACK console automatically evaluates the scalability of the node pool. You can view the scalability level when you create the node pool or after you create the node pool. For more information about ECS instance types, see Overview of instance families. For more information about node pool scalability, see Check the scalability of a node pool. Note ARM-based ECS instances support only images for ARM. For more information about ARM-based node pools, see Configure an ARM-based node pool.
   	Selected Types	The selected instance types are displayed. If you select only GPU-accelerated instances, you can select Enable GPU Sharing on demand. For more information, see GPU sharing overview.
   	System Disk	ESSD AutoPL, Enhanced SSD (ESSD), Standard SSD, and Ultra Disk are supported. The types of system disks that you can select depend on the instance types that you select. Disk types that are not displayed in the drop-down list are not supported by the instance types that you select. For more information about the disk types supported by different instance types, see Instance families. Note If you select Enhanced SSD (ESSD) as the system disk type, you can set a custom performance level for the system disk. You can select higher PLs for ESSDs with larger storage capacities. For example, you can select PL 2 for an ESSD with a storage capacity of more than 460 GiB. You can select PL 3 for an ESSD with a storage capacity of more than 1,260 GiB. For more information, see Capacities and performance levels. You can select Encryption only if you set the system disk type to Enhanced SSD (ESSD). By default, the default service CMK is used to encrypt the system disk. You can also use an existing CMK generated by using BYOK in KMS. You can select More System Disk Types and select a disk type other than the current one in the System Disk section to improve the success rate of system disk creation. The system will attempt to create a system disk based on the specified disk types in sequence.
   	Mount Data Disk	ESSD AutoPL, Enhanced SSD (ESSD), SSD, and Ultra Disk are supported. The disk types that you can select depend on the instance types that you select. Disk types that are not displayed in the drop-down list are not supported by the instance types that you select. For more information about the disk types supported by different instance types, see Instance families. Note If you select Enhanced SSD (ESSD) as the system disk type, you can set a custom performance level for the system disk. You can select higher PLs for ESSDs with larger storage capacities. For example, you can select PL 2 for an ESSD with a storage capacity of more than 460 GiB. You can select PL 3 for an ESSD with a storage capacity of more than 1,260 GiB. For more information, see Capacities and performance levels. You can select Encryption for all disk types when you specify the type of data disk. By default, the default service CMK is used to encrypt the data disk. You can also use an existing CMK generated by using BYOK in KMS. The maximum number of data disks that can be mounted depends on the instance types that you select. You can view the selected data disks and the remaining number of data disks that you can mount on the right side of Mount Data Disk.
   Expected Nodes		The expected number of nodes in the node pool. You can modify the Expected Nodes parameter to adjust the number of nodes in the node pool. If you do not want to create nodes in the node pool, set this parameter to 0. For more information, see Scale a node pool.
   Operating System		ACK supports images for the following operating systems: Alibaba Cloud Linux 3 Alibaba Cloud Linux 3 for ARM. ContainerOS Alibaba Cloud Linux 2 Alibaba Cloud Linux UEFI 2 Windows Windows Core CentOS For more information, see Overview of OS images. Note After you change the OS image of the node pool, the change takes effect only on newly added node. The existing nodes in the node pool still use the original OS image. For more information about how to update the OS images of existing nodes, see Update a node pool. To ensure that all nodes in the node pool use the same OS image, ACK allows you to only update the node OS image to the latest version. ACK does not allow you to change the type of OS image.
   Security Hardening		Disable: disables security hardening for ECS instances. Reinforcement based on classified protection: You can enable security hardening only when you select an Alibaba Cloud Linux 2 or Alibaba Cloud Linux 3 image. Alibaba Cloud provides baselines and the baseline check feature to help you check the compliance of Alibaba Cloud Linux 2 images and Alibaba Cloud Linux 3 images with the level 3 standards of Multi-Level Protection Scheme (MLPS) 2.0. For more information, see ACK reinforcement based on classified protection. Important MLPS Security Hardening enhances the security of OS images to meet the requirements of GB/T 22239-2019 Information Security Technology - Baseline for Classified Protection of Cybersecurity without compromising the compatibility and performance of the OS images. After you enable MLPS Security Hardening, remote logons through SSH are prohibited for root users. You can use Virtual Network Computing (VNC) to log on to the OS from the ECS console and create regular users that are allowed to log on through SSH. For more information, see Connect to a Linux instance by using VNC. OS Security Hardening: You can enable Alibaba Cloud Linux Security Hardening only when the system image is an Alibaba Cloud Linux 2 or Alibaba Cloud Linux 3 image. Note You cannot change the settings of the Security Reinforcement parameter after the cluster is created.
   Logon settings	Logon Type	Valid values: Key Pair, Password, and Later. Note If you select Reinforcement based on classified protection for the Security Reinforcement parameter, only the Password option is supported. Configure the logon type when you create the node pool: Key Pair: Alibaba Cloud SSH key pairs provide a secure and convenient method to log on to ECS instances. An SSH key pair consists of a public key and a private key. SSH key pairs support only Linux instances. For more information, see Overview. Password: The password must be 8 to 30 characters in length, and must contain uppercase letters, lowercase letters, digits, and special characters. Configure the logon type after you create the node pool: For more information, see Bind an SSH key pair to an instance and Reset the logon password of an instance.
   	Username	If you select Key Pair or Password for Logon Type, you must select root or ecs-user as the username.
   Public IP		Specify whether to allocate an IPv4 address to each node. If you clear the check box, no public IP address is allocated. If you select the check box, you must also set the Bandwidth Billing Method and Peak Bandwidth parameters. Note This parameter takes effect only on newly added nodes and does not take effect on existing nodes. If you want to enable an existing node to access the Internet, you must create an elastic IP address (EIP) and associate the EIP with the node. For more information, see Associate an EIP with an ECS instance.
   CloudMonitor Agent		Specify whether to install the CloudMonitor agent. After you install the CloudMonitor agent on ECS nodes, you can view the monitoring information about the nodes in the CloudMonitor console. Note This parameter takes effect only on newly added nodes and does not take effect on existing nodes. If you want to install the CloudMonitor agent on an existing ECS node, go to the CloudMonitor console.

   Advanced settings

   Advanced settings

   Parameter	Description
   ECS Tags	Add tags to the ECS instances that are automatically added during auto scaling. Tag keys must be unique. A key cannot exceed 128 characters in length. Keys and values cannot start with aliyun or acs:. Keys and values cannot contain https:// or http://. An ECS instance can have at most 20 tags. To increase the quota limit, submit an application in the Quota Center console. The following tags are automatically added to an ECS node by ACK and Auto Scaling. Therefore, you can add 17 tags to an ECS node. The following two ECS tags are added by ACK: ack.aliyun.com:<Cluster ID> ack.alibabacloud.com/nodepool-id:<Node pool ID> The following ECS tag is added by Auto Scaling: acs:autoscaling:scalingGroupId:<Scaling group ID>. Note After you enable auto scaling, the following ECS tags are added to the node pool by default: k8s.io/cluster-autoscaler:true and k8s.aliyun.com:true. The auto scaling component simulates scale-out activities based on node labels and taints. For this purpose, the format of node labels is changed to k8s.io/cluster-autoscaler/node-template/label/Label key:Label value and the format of taints is changed to k8s.io/cluster-autoscaler/node-template/taint/Taint key/Taint value:Taint effect.
   Taints	Add taints to nodes. A taint consists of a key, a value, and an effect. A taint key can be prefixed. If you want to specify a prefixed taint key, add a forward slash (/) between the prefix and the remaining content of the key. For more information, see Taints and tolerations. The following limits apply to taints: Key: A key must be 1 to 63 characters in length, and can contain letters, digits, hyphens (-), underscores (_), and periods (.). A key must start and end with a letter or digit. If you want to specify a prefixed key, the prefix must be a subdomain name. A subdomain name consists of DNS labels that are separated by periods (.), and cannot exceed 253 characters in length. It must end with a forward slash (/). For more information about subdomain names, see DNS subdomain names. Value: A value cannot exceed 63 characters in length, and can contain letters, digits, hyphens (-), underscores (_), and periods (.). A value must start and end with a letter or digit. You can also leave a value empty. You can specify the following effects for a taint: NoSchedule, NoExecute, and PreferNoSchedule. NoSchedule: If a node has a taint whose effect is NoSchedule, the system does not schedule pods to the node. NoExecute: Pods that do not tolerate this taint are evicted after this taint is added to a node. Pods that tolerate this taint are not evicted after this taint is added to a node. PreferNoSchedule: The system attempts to avoid scheduling pods to nodes with taints that are not tolerated by the pods.
   Node Label	Add labels to nodes. A label is a key-value pair. A label key can be prefixed. If you want to specify a prefixed label key, add a forward slash (/) between the prefix and the remaining content of the key. The following limits apply to labels: The key of a label must be 1 to 63 characters in length, and can contain letters, digits, hyphens (-), underscores (_), and periods (.). It must start and end with a letter or a digit. If you want to specify a prefixed key, the prefix must be a subdomain name. A subdomain name consists of DNS labels that are separated by periods (.), and cannot exceed 253 characters in length. It must end with a forward slash (/). For more information about subdomain names, see Subdomain names. The following prefixes are used by key Kubernetes components and cannot be used in node labels: kubernetes.io/ k8s.io/ Prefixes that end with kubernetes.io/ or k8s.io/. Example: test.kubernetes.io/. However, you can still use the following prefixes: kubelet.kubernetes.io/ node.kubernetes.io Prefixes that end with kubelet.kubernetes.io/. Prefixes that end with node.kubernetes.io. The value of a label cannot exceed 63 characters in length, and can contain letters, digits, hyphens (-), underscores (_), and periods (.). The value of a label can be empty or start and end with a letter or a digit. If you select Set New Nodes to Unschedulable, nodes are unschedulable when they are added to the cluster. You can set an existing node to schedulable on the Nodes page in the ACK console.
   Scaling Mode	You can select the scaling mode after you enable auto scaling: Standard: Auto scaling is implemented by creating and releasing ECS instances. Swift: Auto scaling is implemented by creating, stopping, and starting ECS instances. This mode starts instances that are in the stopped state when a scale-out activity is needed, which accelerates scaling process. When an instance is stopped, you are charged only for the storage service. This does not apply to Instance families that are equipped with local storage, such as big data instance families and instance families that use local SSDs. For more information about the billing of stopped ECS instances, see Economical mode.
   Scaling Policy	Priority: The system scales the node pool based on the priorities of the vSwitches that you select for the node pool. The vSwitches that you select are displayed in descending order of priority. If Auto Scaling fails to create ECS instances in the zone of the vSwitch with the highest priority, Auto Scaling attempts to create ECS instances in the zone of the vSwitch with a lower priority. Cost Optimization: The system creates instances based on the vCPU unit prices in ascending order. Preemptible instances are preferentially created when multiple preemptible instance types are specified in the scaling configurations. If preemptible instances cannot be created due to reasons such as insufficient stocks, the system attempts to create pay-as-you-go instances. When Billing Method is set to Preemptible Instance, you can configure the following parameters in addition to the Enable Supplemental Preemptible Instances parameter: Percentage of Pay-as-you-go Instances: Specify the percentage of pay-as-you-go instances in the node pool. Valid values: 0 to 100. Enable Supplemental Pay-as-you-go Instances: After you enable this feature, Auto Scaling attempts to create pay-as-you-go ECS instances to meet the scaling requirement if Auto Scaling fails to create preemptible instances for reasons such as that the unit price is too high or preemptible instances are out of stock. Distribution Balancing: The even distribution policy takes effect only when you select multiple vSwitches. This policy ensures that ECS instances are evenly distributed among the zones (the vSwitches) of the scaling group. If ECS instances are unevenly distributed across the zones due to reasons such as insufficient stocks, you can perform a rebalancing operation. Important You cannot change the scaling policy of a node pool after the node pool is created. When Billing Method is set to Preemptible Instance, you can specify whether to turn on Enable Supplemental Preemptible Instances. After this feature is enabled, when a system message that indicates preemptible instances are reclaimed is received, the node pool with auto scaling enabled attempts to create new instance to replace the reclaimed the preemptible instances.
   CPU Policy	The CPU management policy for kubelet nodes. None: The default CPU management policy. Static: This policy allows pods with specific resource characteristics on the node to be granted enhanced CPU affinity and exclusivity. For more information, see CPU management policies.
   Resource Group	The resource group to which the cluster belongs. Each resource can belong to only one resource group. You can regard a resource group as a project, an application, or an organization based on your business scenarios. For more information, see Resource groups.
   Deployment Set	Important To use the deployment set feature, apply to be added to the whitelist in the Quota Center console. You cannot change the deployment set used by control planes after the control planes are created. After you select a deployment set, the maximum number of nodes that can be created in the node pool is limited. By default, the maximum number of nodes supported by a deployment set is 20 × Number of zones. The number of zones depends on the number of vSwitches. Exercise caution when you select the deployment set. To avoid node creation failures, make sure that the ECS quota of the deployment set that you select is sufficient. You need to first create a deployment set in the ECS console and then specify the deployment set when creating a node pool in the ACK console. For more information about how to create a deployment set, see Create a deployment set. You can create a deployment set to distribute ECS instances to be added to a node pool to different physical servers for disaster recovery. This improves the availability of your businesses. If you specify a deployment set when you create ECS instances, the instances are created and distributed based on the deployment strategy that you preset for the deployment set within the specified region. For more information, see Best practices for associating deployment sets with node pools.
   Custom Security Group	You can select Basic Security Group or Advanced Security Group but you can select only one security group type. You cannot modify the security groups of node pools or change the type of security group. For more information about security groups, see Overview. Important To use custom security groups, apply to be added to the whitelist in Quota Center. Each ECS instance supports up to five security groups. Make sure that the quota of security groups for your ECS instance is sufficient. For more information about security group limits and how to increase the quota limit of security groups for your ECS instance, see Security group limits. If you select an existing security group, the system does not automatically configure security group rules. This may cause errors when you access the nodes in the cluster. You must manually configure security group rules. For more information about how to manage security group rules, see Configure security groups for clusters.
   Custom Image	After you specify Custom Image, the custom image will replace the default system image. Custom Images: All nodes in the cluster are deployed based on the custom image. For more information about how to create a custom image, see Create a cluster or node pool based on a custom image. Shared Images: All nodes in the cluster are deployed based on the shared image. For more information about shared images, see Procedure. Note You can use only custom images created based on Alibaba Cloud Linux, RHEL 8.x, and CentOS 7.x. To use this feature, submit an application in the Quota Center console.
   RDS Whitelist	Click Select RDS Instance to add node IP addresses to the whitelist of an ApsaraDB RDS instance.
   Custom Node Name	Specify whether to use a custom node name. If you choose to use a custom node name, the name of the node, name of the ECS instance, and hostname of the ECS instance are changed. Note If a Windows instance uses a custom node name, the hostname of the instance is fixed to an IP address. You need to use hyphens (-) to replace the periods (.) in the IP address. In addition, no prefix or suffix is allowed in the IP address. A custom node name consists of a prefix, an IP substring, and a suffix. A custom node name must be 2 to 64 characters in length. The name must start and end with a lowercase letter or digit. The prefix and suffix can contain letters, digits, hyphens (-), and periods (.). The prefix and suffix must start with a letter and cannot end with a hyphen (-) or period (.). The prefix and suffix cannot contain consecutive hyphens (-) or periods (.). The prefix is required due to ECS limits and the suffix is optional. For example, the node IP address is 192.XX.YY.55, the prefix is aliyun.com, and the suffix is test. If the node is a Linux node, the node name, ECS instance name, and ECS instance hostname are aliyun.com192.XX.YY.55test. If the node is a Windows node, the ECS instance hostname is 192-XX-YY-55 and the node name and ECS instance name are aliyun.com192.XX.YY.55test.
   Pre-defined Custom Data	To use this feature, submit an application in the Quota Center console. Nodes automatically run predefined scripts before they are added to the cluster. For more information about user-data scripts, see User-data scripts. For example, if you enter echo "hello world", a node runs the following script: #!/bin/bash echo "hello world" [Node initialization script]
   User Data	Nodes automatically run user-data scripts after they are added to the cluster. For more information about user-data scripts, see User-data scripts. For example, if you enter echo "hello world", a node runs the following script: #!/bin/bash [Node initialization script] echo "hello world" Note After you create a cluster or add nodes, the execution of the user-data script on a node may fail. We recommend that you log on to a node and run the grep cloud-init/var/log/messages command to view the execution log and check whether the execution succeeds or fails on the node.
   Private Pool Type	Note This parameter is in canary release. Valid values: Open, Do Not Use, and Specified. Open: The system automatically matches an open private pool. If no matching is found, resources in the public pool are used. Do Not Use: No private pool is used. Only resources in the public pool are used. Specified: Specify a private pool by ID. If the specified private pool is unavailable, ECS instances fail to start up. For more information, see Private pools.

4. Click Confirm Order.

   If the Status column of the node pool in the node pool list displays Initializing, the node pool is being created. After the node pool is created, the Status column of the node pool displays Active.

What to do next

After the node pool is created, you can click an action in the Actions column of the node pool or click More in the Actions column to perform one of the operations that are described in the following table.

References

• Remove nodes

• Manage node labels

• Manage taints

• Resource reservation policy