This topic describes the limits that apply when you use Container Service for Kubernetes (ACK) clusters.

Overview

Before you use ACK, take note of the following limits:

  • You must pass real-name verification before you can create an ACK cluster.
  • You cannot perform the following operations on ACK clusters:
    • Change the virtual private cloud (VPC).
    • Change a managed Kubernetes cluster to a dedicated Kubernetes cluster, or change a professional managed Kubernetes cluster to a standard managed Kubernetes cluster.
    • Change the network plug-in.
    • Change the volume plug-in.
    • Migrate applications across namespaces.
  • The following limits apply to Elastic Compute Service (ECS) instances that run in ACK clusters:
    • ECS instances support the pay-as-you-go and subscription billing methods. Other resources, such as Server Load Balancer (SLB) instances, support only the pay-as-you-go billing method. You can change the billing method from pay-as-you-go to subscription in the ECS console.
    • When you create clusters, expand clusters, or perform auto scaling of clusters, you may fail to create nodes due to resource quota limits or inventory availability.
    • If you want to create subscription ECS instances when you create a cluster, you may fail to create the ECS instances due to resource quota limits or inventory availability. After a subscription ECS instance is created, you cannot release the ECS instance before the subscription expires.
      Note To avoid these issues, we recommend that you create pay-as-you-go ECS instances when you create a cluster. You can change the billing method from pay-as-you-go to subscription in the ECS console based on your requirements.
    • Requirements for ECS specifications: You must select ECS instances with at least four vCPUs and at least 8 GiB of memory.
  • Limits on access to the control plane components of a cluster:

    Bandwidth limits apply when you access the control pane components of a cluster by calling API operations (API Server) or running commands (etcd). If you read a large number of cluster events at a time, bandwidth throttling may be triggered and you may fail to read the events. We recommend that you query cluster events in the event center. Alternatively, you can add paging parameters, such as --chunk-size=500, to the API request or command lines to reduce the number of events to be read. If you frequently trigger bandwidth throttling in a standard managed Kubernetes cluster, you can change the cluster to a professional managed Kubernetes cluster.

    For more information about the event center, see Scenario 1: Use node-problem-detector with the Kubernetes event center of Log Service to sink cluster events.

    For more information about how to change a standard managed Kubernetes cluster to a professional managed Kubernetes cluster, see Hot migration from standard managed Kubernetes clusters to professional managed Kubernetes clusters.

Quota limits

Item Per Alibaba Cloud account Quota increase
Real-name verification Real-name verification is required. Not supported.
Create pay-as-you-go resources N/A N/A
Maximum number of dedicated Kubernetes clusters and managed Kubernetes clusters Default: 50. Maximum: 2,000.

Navigate to the Quota Center page to submit a ticket.

Maximum number of master nodes and worker nodes in an ACK cluster Default: 100. Maximum: 5,000.

Navigate to the Quota Center page to submit a ticket.

Maximum number of pods on a worker node The maximum number is configurable when you create the cluster in the console. The upper limit is 256. Not supported.
Maximum number of serverless Kubernetes clusters 5

Navigate to the Quota Center page to submit a ticket.

Notice The maximum number of pods on a node cannot be increased. The quota increase methods apply only to the maximum number of clusters within an Alibaba Cloud account and the maximum number of nodes in a cluster.

Quota limits on underlying cloud resources

Category Item Quota for general users Quota increase
Computing Resource Orchestration Service (ROS) quota Default: 100.

Submit a ticket.

vCPU quota of pay-as-you-go instances 500 vCPU cores

Submit a ticket.

High-specification pay-as-you-go instances (with more than 16 vCPU cores) Unavailable for purchase. Only pay-as-you-go instances with less than 16 vCPUs can be purchased.

Submit a ticket.

vCPU quota of preemptible instances 800 vCPU cores

Submit a ticket.

Change from pay-as-you-go to subscription Not supported by the following instance families: t1, s1, s2, s3, c1, c2, m1, m2, n1, n2, and e3.

Submit a ticket.

Auto Scaling (ESS) The maximum number of ECS instances in a scaling group is 2,000.

Submit a ticket.

Operating systems Nodes that run the following operating systems can be added to an ACK cluster:
  • Alibaba Cloud Linux 2
  • CentOS 7.x
    Note CentOS 8.x and later are not supported.
  • Windows Server 2009 and Windows Server 2009 Core.
N/A
Networking Maximum number of custom route entries in a route table 48

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Maximum number of vSwitches in a VPC 24

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Maximum number of VPCs within an Alibaba Cloud account 10

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Maximum number of private IP addresses in a VPC 65,535 N/A
Maximum number of IP addresses that can be added to a basic security group 2,000 N/A
Maximum number of elastic network interfaces (ENIs) 50,000 N/A
Maximum number of elastic IP addresses (EIPs) within an Alibaba Cloud account 20

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SLB Maximum number of SLB instances within an Alibaba Cloud account 60

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Maximum number of backend servers that can be attached to an SLB instance 200 N/A
Maximum number of listeners that can be added to an SLB instance 50

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Maximum number of times that an ECS instance can be added to SLB instances as a backend server 50 N/A
Elastic Block Storage (EBS) Maximum number of pay-as-you-go disks in all regions within an Alibaba Cloud account The quota is five times the number of ECS instances across all regions within an Alibaba Cloud account. You can create at least 10 pay-as-you-go disks within each Alibaba Cloud account.

Submit a ticket.

Maximum capacity of pay-as-you-go disks that are used as data disks within an Alibaba Cloud account Subject to ECS resource usage, regions, and disk types. You can go to the Privileges & Quotas page in the ECS console to view details. For more information, see View quotas (old version).

Submit a ticket.