Creating a Node Pool¶
Scenario¶
This section describes how to create a node pool and perform operations on the node pool. For details about how a node pool works, see Node Pool Overview.
Procedure¶
Log in to the CCE console.
Click the cluster name to access the cluster console. Choose Nodes in the navigation pane. In the right pane, click the Node Pools tab.
In the upper right corner of the page, click Create Node Pool.
Basic Settings
Table 1 Basic settings¶ Parameter
Description
Node Pool Name
Name of a node pool. By default, the name is in the format of Cluster name-nodepool-Random number. If you do not want to use the default name format, you can customize the name.
Configurations
You can configure the flavor and OS of a cloud server, on which your containerized applications run.
Table 2 Node configuration parameters¶ Parameter
Description
Node Type
Select a node type based on service requirements. Then, you can select a proper flavor from the node flavor list.
CCE standard clusters support the following node types:
ECS (VM): A virtualized ECS is used as a cluster node.
Specifications
Select a node flavor based on service requirements. The available node flavors vary depending on regions or AZs. For details, see the CCE console.
Note
If a node pool is configured with multiple node flavors, only the flavors (which can be located in different AZs) of the same node type are supported. For example, a node pool consisting of general computing-plus nodes supports only general computing-plus node flavors, but not the flavors of general computing nodes.
A maximum of 10 node flavors can be added to a node pool (the flavors in different AZs are counted separately). When adding a node flavor, you can choose multiple AZs, but you need to specify them.
Nodes in a newly created node pool are created using the default flavor. If the resources for the default flavor are insufficient, node creation will fail.
After a node pool is created, the flavors of existing nodes cannot be deleted.
Container Engine
The container engines supported by CCE include Docker and containerd, which may vary depending on cluster types, cluster versions, and OSs. Select a container engine based on the information displayed on the CCE console. For details, see Mapping between Node OSs and Container Engines.
OS
Select an OS type. Different types of nodes support different OSs.
Public image: Select a public image for the node.
Private image: Select a private image for the node.
Note
Service container runtimes share the kernel and underlying calls of nodes. To ensure compatibility, select a Linux distribution version that is the same as or close to that of the final service container image for the node OS.
Login Mode
Key Pair
Select the key pair used to log in to the node. You can select a shared key.
A key pair is used for identity authentication when you remotely log in to a node. If no key pair is available, click Create Key Pair.
Storage Settings
Configure storage resources on a node for the containers running on it. Select a disk type and configure its size based on service requirements.
Table 3 Storage configuration parameters¶ Parameter
Description
System Disk
System disk used by the node OS. The value ranges from 40 GiB to 1024 GiB. The default value is 50 GiB.
Encryption: System disk encryption safeguards your data. Snapshots generated from encrypted disks and disks created using these snapshots automatically inherit the encryption setting. Only the nodes of the Elastic Cloud Server (VM) type in certain regions support system disk encryption. For details, see the console.
Not encrypted is selected by default.
If you select Enabled (key) for System Disk Encryption, choose an existing key. If no key is available, click View Key List and create a key. After the key is created, click the refresh icon next to the text box.
If you select Enabled (KMS key ID) for System Disk Encryption, enter a KMS key (which can be shared by others) in the current region.
Data Disk
At least one data disk is required for the container runtime and kubelet. The data disk cannot be deleted or uninstalled. Otherwise, the node will be unavailable.
First data disk: used for container runtime and kubelet components. The value ranges from 20 GiB to 32768 GiB. The default value is 100 GiB.
Other data disks: You can set the data disk size to a value ranging from 10 GiB to 32768 GiB. The default value is 100 GiB.
Note
If the node flavor is disk-intensive or ultra-high I/O, one data disk can be a local disk.
Local disks may break down and do not ensure data reliability. Store your service data in EVS disks, which are more reliable than local disks.
Advanced Settings
Expand the area and configure the following parameters:
Data Disk Space Allocation: allocates space for container engines, images, and ephemeral storage for them to run properly. For details about how to allocate data disk space, see Data Disk Space Allocation.
Data Disk Encryption: Data disk encryption safeguards your data. Snapshots generated from encrypted disks and disks created using these snapshots automatically inherit the encryption setting.
Not encrypted is selected by default.
If you select Enabled (key) for Data Disk Encryption, choose an existing key. If no key is available, click View Key List and create a key. After the key is created, click the refresh icon next to the text box.
If you select Enabled (KMS key ID) for Data Disk Encryption, enter a KMS key (which can be shared by others) in the current region.
Adding data disks
A maximum of 16 data disks can be attached to an ECS. By default, a raw disk is created without any processing. You can also click Expand and select any of the following options:
Default: By default, a raw disk is created without any processing.
Mount Disk: The data disk is attached to a specified directory.
Use as PV: applicable when there is a high performance requirement on PVs. The node.kubernetes.io/local-storage-persistent label is added to the node with PV configured. The value is linear or striped.
Use as ephemeral volume: applicable when there is a high performance requirement on emptyDir.
Note
Local PVs are supported only when the cluster version is v1.21.2-r0 or later and the Everest add-on version is 2.1.23 or later. Version 2.1.23 or later is recommended.
Local EVs are supported only when the cluster version is v1.21.2-r0 or later and the Everest add-on version is 1.2.29 or later.
Local PVs and local EVs can be written in the following modes:
Linear: A linear logical volume integrates one or more physical volumes. Data is written to the next physical volume when the previous one is used up.
Striped: A striped logical volume stripes data into blocks of the same size and stores them in multiple physical volumes in sequence. This allows data to be concurrently read and written. A storage pool consisting of striped volumes cannot be scaled-out. This option can be selected only when multiple volumes exist.
Network Settings
Configure networking resources to allow node and containerized application access.
Table 4 Configuration parameters¶ Parameter
Description
Virtual Private Cloud
The VPC to which the cluster belongs by default, which cannot be changed.
Node Subnet
The node subnet selected during cluster creation is used by default. You can choose another subnet instead.
Multiple subnets: You can select multiple subnets in the same VPC for nodes. Newly added nodes will preferentially use the IP addresses from the top-ranking subnet.
Single subnet: Only one subnet is configured for your node pool. If the IP addresses of a single subnet are insufficient, configure multiple subnets. Otherwise, a node pool scale-out may fail.
Node IP Address
Random allocation is supported.
Associate Security Group
Security group used by the nodes created in the node pool. A maximum of five security groups can be selected.
When a cluster is created, a node security group named {Cluster name}-cce-node-{Random ID} is created and used by default.
Traffic needs to pass through certain ports in the node security group to ensure node communications. Ensure that you have enabled these ports if you select another security group.
Note
After a node pool is created, its associated security group cannot be modified.
Advanced Settings
Configure advanced node capabilities such as labels, taints, and startup command.
Table 5 Advanced configuration parameters¶ Parameter
Description
Resource Tag
You can add resource tags to classify resources.
You can create predefined tags on the TMS console. The predefined tags are available to all resources that support tags. You can use predefined tags to improve the tag creation and resource migration efficiency.
CCE will automatically create the "CCE-Dynamic-Provisioning-Node=Node ID" tag.
Kubernetes Label
A key-value pair added to a Kubernetes object (such as a pod). After specifying a label, click Add Label for more. A maximum of 20 labels can be added.
Labels can be used to distinguish nodes. With workload affinity settings, pods can be scheduled to a specified node. For more information, see Labels and Selectors.
Taint
This parameter is left blank by default. You can add taints to configure anti-affinity for the node. A maximum of 20 taints are allowed for each node. Each taint contains the following parameters:
Key: A key must contain 1 to 63 characters, starting with a letter or digit. Only letters, digits, hyphens (-), underscores (_), and periods (.) are allowed. A DNS subdomain name can be used as the prefix of a key.
Value: A value must contain 1 to 63 characters, starting with a letter or digit. Only letters, digits, hyphens (-), underscores (_), and periods (.) are allowed.
Effect: Available options are NoSchedule, PreferNoSchedule, and NoExecute.
For details, see Managing Node Taints.
Note
For a cluster of v1.19 or earlier, the workload may have been scheduled to a node before the taint is added. To avoid such a situation, select a cluster of v1.19 or later.
Synchronization for Existing Nodes
After the options are selected, changes to resource tags and Kubernetes labels/taints in a node pool will be synchronized to existing nodes in the node pool.
New Node Scheduling
Default scheduling policy for the nodes newly added to a node pool. If you select Unschedulable, newly created nodes in the node pool will be labeled as unschedulable. In this way, you can perform some operations on the nodes before pods are scheduled to these nodes.
Scheduled Scheduling: After scheduled scheduling is enabled, new nodes will be automatically scheduled after the custom time expires.
Disabled: By default, scheduled scheduling is not enabled for new nodes. To manually enable this function, go to the node list. For details, see Configuring a Node Scheduling Policy in One-Click Mode.
Custom: the default timeout for unschedulable nodes. The value ranges from 0 to 99 in the unit of minutes.
Note
If auto scaling of node pools is also required, ensure the scheduled scheduling is less than 15 minutes. If a node added through Autoscaler cannot be scheduled for more than 15 minutes, Autoscaler determines that the scale-out failed and triggers another scale-out. Additionally, if the node cannot be scheduled for more than 20 minutes, the node will be scaled in by Autoscaler.
After this function is enabled, nodes will be tainted with node.cloudprovider.kubernetes.io/uninitialized during a node pool creation or update.
Max. Pods
Maximum number of pods that can run on the node, including the default system pods.
This limit prevents the node from being overloaded with pods.
This number is also decided by other factors. For details, see Maximum Number of Pods That Can Be Created on a Node.
ECS Group
An ECS group logically groups ECSs. The ECSs in the same ECS group comply with the same policy associated with the ECS group.
Anti-affinity: ECSs in an ECS group are deployed on different physical hosts to improve service reliability.
Select an existing ECS group, or click Add ECS Group to create one. After the ECS group is created, click the refresh icon.
Pre-installation Command
Pre-installation script command, in which Chinese characters are not allowed. The script command will be Base64-transcoded. The characters of both the pre-installation and post-installation scripts are centrally calculated, and the total number of characters after transcoding cannot exceed 10240.
The script will be executed before Kubernetes software is installed. Note that if the script is incorrect, Kubernetes software may fail to be installed.
Post-installation Command
Pre-installation script command, in which Chinese characters are not allowed. The script command will be Base64-transcoded. The characters of both the pre-installation and post-installation scripts are centrally calculated, and the total number of characters after transcoding cannot exceed 10240.
The script will be executed after Kubernetes software is installed, which does not affect the installation.
Note
Do not run the reboot command in the post-installation script to restart the system immediately. To restart the system, run the shutdown -r 1 command to restart with a delay of one minute.
Agency
An agency is created by the account administrator on the IAM console. Using an agency, you can share your cloud server resources with another account, or entrust a more professional person or team to manage your resources.
If no agency is available, click Create Agency on the right to create one.
Click Next: Confirm.
Click Submit.