Last updated: 2021-12-20 10:21:45
    Note:

    Elastic cluster is a service of Elastic Kubernetes Service (EKS). Before you use this service, please read the following information.

    Billing Mode

    EKS adopts the pay-as-you-go billing method. For more information about EKS billing, please see Billing Overview, Product Pricing, and Purchase Limits.

    Pod Specification Configuration

    Container runtime resources and bills depend on the Pod specification configuration. Please note the Pod specification configuration and specific methods supported by elastic clusters. For more information, please see Resource Specifications and Specifying Resource Specifications.

    Pod Temporary Storage

    When created, each Pod is allocated less than 20 GiB of temporary image storage.

    Note:

    • Temporary image storage will be deleted when the Pod lifecycle ends. Therefore, please do not store important data in it.
    • Due to image storage, the actual available storage capacity is less than 20 GiB.
    • It is recommended to mount important data and large files to Volume for persistent storage.

    Kubernetes Version

    Kubernetes v1.12 and earlier versions are not supported.

    Notes

    Elastic clusters do not have nodes. Therefore, some features, which depend on node components such as Kubelet and Kube-proxy, are not supported.

    Node

    • Currently, adding or managing a physical node is not supported.
    • EKS nodes will be replaced by "virtual nodes", and each virtual node corresponds to a specified VPC subnet in the container network.
    • The virtual nodes also support scheduling operations such as node affinity, taint, and cordoning.
    • The number of Pods that can be scheduled on a virtual node is only subject to the number of IPs in the corresponding VPC subnet.

    Container network

    • The container network of an elastic cluster is a VPC which is at the same level as Tencent Cloud services such as CVM and TencentDB. Each Pod in the cluster occupies a VPC subnet IP.
    • Pods can directly communicate through the VPC with Pods or other Tencent Cloud services in the same VPC, without performance loss.

    Pod isolation

    Pods in the elastic cluster and the CVM have the same security isolation. Pods are scheduled and created on the underlying physical server of Tencent Cloud, and resource isolation between Pods is guaranteed by the virtualization technology during the creation.

    Kernel

    Only the kernel parameters starting with "net" can be defined.

    Workload

    You cannot deploy workloads of the DaemonSet type through EKS.

    Service

    You cannot deploy services of the NodePort type through EKS.

    In addition, for the ordinary Kubernetes cluster, the Service of ClusterIP type relies on nodes to forward traffic. To make the elastic cluster compatible with the Service of ClusterIP type, you need to specify another VPC subnet as the cluster's Service CIDR block. Each ClusterIP Service will create a private network CLB in this subnet, which will occupy one IP in the subnet, to forward traffic. Please ensure that the subnet has sufficient available IPs.

    Volume

    EKS supports the volume of the Hostpath type. For more information, see Instructions for Other Storage Volumes.
    EKS clusters may not necessarily meet your expectations because they don’t have nodes, although EKS is still compatible with Host-related parameters (such as Hostpath, Hostnetwork: true, and DnsPolicy: ClusterFirstWithHostNet, etc.) in the Pod. For example, you want to use Hostpath to share data, but the two Pods scheduled to the same virtual node may be the Hostpath of different hosts. Therefore, we recommend that the tasks you run on the EKS cluster do not strongly depend on Host-related parameters.