Limits and quotas for container service for kubernetes - Container Service for Kubernetes

Review cluster quotas, capacity limits, and cloud service quotas for Container Service for Kubernetes (ACK).

Limitations

Product and cluster configuration limits

Limit	Description
Account verification	Before creating an ACK cluster, complete identity verification and activate ACK.
Cluster configuration	After creating an ACK cluster, you cannot change these configurations. You cannot change the cluster VPC. You cannot directly change the cluster type. For example, an ACK dedicated cluster cannot be changed to an ACK managed cluster. You can hot migrate ACK dedicated clusters to ACK managed clusters Pro Edition. Cluster specifications cannot be directly changed, such as from ACK managed Pro cluster to ACK managed Basic cluster. You can hot migrate ACK managed clusters from Basic to Pro Edition. You cannot switch between the Terway and Flannel network plugins.
ECS instance (node instance) configuration	Supports pay-as-you-go, subscription, and preemptible instance billing. In the ECS console, convert pay-as-you-go instances to subscription instances. Due to quota and inventory limits of underlying products such as ECS, only some nodes may be created when creating, scaling out, or auto-scaling clusters. Node specifications must be at least 4 CPU cores and 8 GB memory. See ECS Instance Type Configuration Recommendations.
Control plane traffic	Accessing control plane components (API Server, etcd) via API or CLI may trigger rate limiting when reading many events at once. Use Event Center to query cluster events, or add pagination parameters to reduce the size of a single request (e.g., `--chunk-size=500`). See Scenario 1: Monitor Cluster Events Using NPD and SLS Kubernetes Event Center. If you frequently hit rate limits in an ACK managed Basic cluster, migrate to an ACK managed Pro cluster. See Hot migrate an ACK Basic cluster to an ACK Pro cluster.

Single-cluster capacity limits

ACK managed Pro cluster and ACK managed Basic cluster are designed for different use cases and support different capacity limits.

ACK managed Pro cluster: Recommended for enterprise production environments.
If you use the Terway network plugin with IPvlan enabled, a 5,000-node cluster supports up to 50,000 pods and a combined maximum of 64,000 Service-to-pod mappings.
ACK managed Basic cluster: Intended only for personal testing and educational purposes.

The following table lists the maximum capacity for different resource types within a single cluster.

Resource type	ACK managed Pro cluster	ACK managed Basic cluster
etcd storage capacity	8 GB	2 GB
Total etcd object size per resource type	800 MB	200 MB
Nodes	Flannel: 200 (default), up to 1,000 Terway: 5,000 (default), up to 15,000	10
Pods	Up to 150,000 Varies based on the network plugin and available pod CIDR block configuration	300
Namespaces	10,000	100
ConfigMaps	30,000	300
Secrets	100,000	1,000
Persistent volume claims (PVCs)	100,000	1,000
Persistent volumes (PVs)	100,000	1,000
Services	10,000	100
Roles	50,000	500
RoleBindings	50,000	500
CustomResourceDefinitions (CRDs)	100,000	1,000
Custom resources (CRs) per CRD	100,000	1,000

Quotas

Cluster quotas

The following table lists only the default quotas. To view adjustable quotas and their maximum limits, or to request a quota increase, go to the Quota Center.

Notes on quota adjustments:

Maximum node pools per cluster (①): If you request an increase for this quota, you must also request an increase for the maximum number of Auto Scaling (ESS) groups. Log on to the Quota Platform to submit a request.
Maximum pods per node (②): This limit depends on your cluster network plugin.
- Flannel: Determined by CIDR block configuration specified during cluster creation (Refer to the following table). This limit cannot be increased.
- Terway: Depends on the number of elastic network interfaces (ENIs) supported by the ECS instance type. Use newer and higher-specification ECS instance types.

ACK managed cluster

Resource	Basic edition	Pro edition
Maximum clusters per Alibaba Cloud account	2	100
Maximum node pools per cluster^①	10	100
Maximum nodes per cluster	10	Flannel: 200 (default), up to 1,000 Terway: 5,000 (default), up to 15,000
Maximum serverless pods per cluster	1,000	50,000 Important We recommend a maximum of 20,000 if pods are mapped to a large number of Services.
Maximum pods per single node^②	Flannel: 256 Terway: Depends on node specifications. See Calculate pod limits per node.
Quota increase	Cannot be increased	Submit a request in the Quota Center.

ACK dedicated cluster

Maximum clusters per Alibaba Cloud account: 0 (Creation stopped)
Maximum node pools per cluster^①: 100
Maximum nodes per cluster:
- Flannel: 200 (default), up to 1,000
- Terway: 5,000 (default), up to 15,000
Maximum pods per node^②:
- Flannel: 256
- Terway: Depends on node specifications. See Calculate pod limits per node.
To increase quota, log on to the Quota Center console and submit an application.

ACK serverless cluster

Resource	Basic edition	Pro edition
Maximum clusters per Alibaba Cloud account	2	100
Maximum pods per cluster	1,000	50,000 Important We recommend a maximum of 20,000 if pods are mapped to a large number of Services.
Quota increase	Submit a request in the Quota Center.

ACK Edge cluster

Resource	Basic edition	Pro edition
Maximum clusters per Alibaba Cloud account	2	100
Maximum node pools per cluster^①	10	100
Maximum nodes per cluster	10	1,000
Maximum pods per node^②	256	256
Quota increase	Cannot be increased	Submit a request in the Quota Center.

Registered clusters

Maximum clusters per Alibaba Cloud account: 5
Maximum node pools per cluster^①: 100
Maximum pods per node^②: 256
To increase quota, log on to the Quota Center console and submit an application.

Underlying cloud service quotas

Service type	Resource	Default limit	Quota increase
ECS	Resource Orchestration Service (ROS) quota	100	Submit a ticket
	Pay-as-you-go instance vCPU limit	500 cores	Submit a ticket
	Pay-as-you-go high-spec instances (> 16 vCPUs)	0 (Only instances with < 16 vCPUs are allowed by default)	Submit a ticket
	Preemptible instance vCPU limit	800 cores	Submit a ticket
	Pay-as-you-go to subscription conversion	Unsupported instance types (families): t1, s1, s2, s3, c1, c2, m1, m2, n1, n2, e3	Submit a ticket
	Maximum ECS instances per ESS scaling group	2,000	Submit a request in the Quota Center.
	Operating system	Nodes that run the following operating systems can be added to an ACK cluster: Alibaba Cloud Linux CentOS 7.x Note CentOS 8.x and later are not supported. Windows Server 2019 and Windows Server version 1809 and later.	None
Network	Applies only to clusters with the Flannel network plugin Maximum custom route entries per route table (excluding dynamic routes)	200	See General Quotas.
	Maximum vSwitches per VPC	150
	Maximum VPCs per region	10
	Maximum private IPs per security group (per VPC/region/account)	Basic security groups: 6,000 Advanced security groups: 65,535	For basic security groups, apply on the Quota Center.
	Maximum security groups per account per region	Quota ID: `q_security-groups`. See View or increase ECS quotas.
	Maximum ENIs (secondary ENIs) per account per region	Quota ID: `q_elastic-network-interfaces`	View or increase ECS quotas
	Maximum pay-as-you-go Elastic IPs (EIPs) per account	20	Increase the quota on the Quota Management or Quota Center.
Server Load Balancer	Maximum Classic Load Balancer (CLB) instances per account	30	Use one of these methods: Go to the Quota Management page in the CLB console, find the quota slb_quota_instances_num, and then click Apply in the Actions column. For more information, see Manage quotas. Log on to the Quota Center console and request a quota increase. For more information, see Manage CLB quotas.
	Maximum backend servers per CLB instance	200	Use one of these methods: Go to the Quota Management page in the CLB console, find the quota slb_quota_backendservers_num, and then click Apply in the Actions column. For more information, see Manage quotas. Log on to the Quota Center console and request a quota increase. For more information, see Manage CLB quotas.
	Maximum listeners per CLB instance	50	Use one of these methods: Go to the Quota Management page in the CLB console, find the quota slb_quota_listeners_num, and then click Apply in the Actions column. For more information, see Manage quotas. Log on to the Quota Center console and request a quota increase. For more information, see Manage CLB quotas.
	Maximum times a server can be added to a CLB instance as a backend server	50	Cannot be increased.
Elastic Block Storage	Maximum pay-as-you-go cloud disks across all regions	Total ECS instances × 5. (Minimum: 10 disks)	submit a ticket
Elastic Block Storage	Maximum pay-as-you-go data disk capacity	Depends on ECS usage, region, and disk type. See Elastic Block Storage.	submit a ticket

References

Each cluster type has specific precautions and risky operations. See Usage notes and risky operations.
Follow Recommended workload configurations for stable and reliable cluster applications.
Adding nodes increases pod capacity, but oversized clusters may degrade availability and performance. See Recommendations for large-scale clusters.