This topic describes ACK Serverless and its benefits, use scenarios, and key features to help you quickly get started with ACK Serverless clusters. This topic also compares ACK Serverless clusters with ACK clusters.
Starting February 17, 2025, Alibaba Cloud Container Service for Kubernetes (ACK) Serverless disables cluster creation for new users who have never created an ACK Serverless cluster. Instead, you can leverage serverless container computing capabilities through Container Compute Service (ACS). ACS clusters provide full lifecycle management for enterprise-level Kubernetes containerized applications, delivering enhanced features and more convenient services. For more information about ACS, see ACS product overview.
For users who have not created an ACK Serverless cluster, the interface for creating a new ACK Serverless cluster is unavailable. To use Serverless container computing capabilities:
Create an ACS cluster and leverage Serverless resources within it.
Use Serverless computing elastically in ACK Managed Cluster Pro Edition.
For existing ACK Serverless cluster users, your current ACK Serverless clusters and new cluster creation within default quotas remain unaffected. You can continue operations as documented, with no service interruptions or adjustments required.
For more information about this product change, see [Product Changes] Announcement on deprecation of cluster creation interface for new users of ACK Serverless clusters.
Overview
ACK Serverless is a serverless container service provided by Alibaba Cloud. ACK Serverless clusters provided by ACK Serverless are nodeless. You can deploy applications without the need to plan, purchase, or maintain nodes. You are charged for CPU and memory resources allocated to applications on a pay-as-you-go basis. ACK Serverless clusters provide Kubernetes-compatible capabilities to allow beginners to focus on applications instead of infrastructure management.
ACK Serverless clusters are classified into ACK Serverless Basic clusters and ACK Serverless Pro clusters. ACK Serverless Pro clusters are developed based on ACK Serverless Basic clusters and provide improved security and reliability for large-scale production. ACK Serverless clusters are also covered by the service level agreement (SLA) that supports compensation clauses. For more information about ACK Serverless Pro clusters, see ACK Serverless Pro cluster overview.
Benefits
Benefit | Description |
Out-of-the-box | You can quickly create ACK Serverless clusters and deploy applications in ACK Serverless clusters without the need to manage Kubernetes nodes and servers. |
Ultralarge capacity | You can create more than 50,000 pods in an ACK Serverless cluster without the need to add additional configurations or design the size of the cluster. Important We recommend that you keep the number of pods under 20,000 if a large number of pods are associated with the Service. |
Second-level scaling | You can create thousands of pods within a short period of time to handle traffic spikes. |
Predictive scaling | ACK Serverless can predict resource demand based on historical data and then scale resources promptly during peak hours. |
Compatibility with cloud-native services | ACK Serverless is fully compatible with Kubernetes and supports Kubernetes-native applications and ecosystems. You can seamlessly migrate Kubernetes applications to ACK Serverless. |
Isolation for security | You can deploy pods on elastic container instances. Instances on which pods are deployed are isolated from each other by using the lightweight virtual sandbox technology. |
Cost savings | Pods are created on demand. You are charged based on the resources used by your applications. The serverless architecture helps prevent resource waste and reduce O&M costs. |
Service integration | You can seamlessly integrate containerized applications with the fundamental services of Alibaba Cloud. Containers can communicate with applications deployed on virtual machines. |
Compared with ACK Serverless Basic clusters, ACK Serverless Pro clusters are more reliable, ensure higher service uptime, and allow you to deploy more pods. You can seamlessly migrate applications from ACK Serverless Basic clusters to ACK Serverless Pro clusters. |
Comparison between ACK Serverless clusters and ACK clusters
The following figure compares the left-side ACK cluster with the right-side ACK Serverless cluster.
Use scenarios
Scenario | Description |
Application hosting | In ACK Serverless clusters, you do not need to manage or maintain nodes or plan the cluster size. This greatly reduces the costs on infrastructure management and maintenance. |
Traffic spikes | For fluctuating workloads in industries such as online education and e-commerce, ACK Serverless clusters can scale resources within seconds to help you reduce computing costs, prevent resource waste, and withstand traffic spikes. For more information, see Auto scaling overview. |
Data computing | To handle computing jobs such as Spark jobs, ACK Serverless clusters can start large numbers of pods within a short period of time and release pods immediately after the jobs are complete to reduce computing costs. For more information, see Use ACK Serverless to create Spark tasks. |
CI/CD | You can use ACK Serverless clusters to build a continuous integration (CI) environment, such as Jenkins or Gitlab-Runner, to quickly compile application code, build and push images, and create pipelines. CI jobs are isolated from each other. You do not need to maintain resource pools, which reduces computing costs. For more information, see Deploy Jenkins in an ACK Serverless cluster and then create and deploy an application and Elastic and cost-effective CI/CD based on ACK Serverless. |
CronJobs | You can run CronJobs in ACK Serverless clusters. The billing stops after the jobs are complete. You do not need to maintain resource pools, which helps prevent resource waste. For more information, see Use CronHPA for scheduled horizontal scaling. |
Key features
ACK Serverless clusters provide Kubernetes-compatible capabilities. In addition to Kubernetes-native features, we recommend that you pay attention to the following features when you use ACK Serverless clusters.
ECI Profile
Pods in ACK Serverless clusters run on elastic container instances. You can configure Elastic Container Instance Profile to control pods and pod-related cluster actions in a fine-grained manner. Elastic Container Instance Profile is a ConfigMap named eci-profile in the kube-system namespace. The following table describes the key parameters.
Parameter | Description |
vpcId | The unique identifier of the virtual private cloud (VPC) in which pods are deployed. |
securityGroupId | The unique identifier of the Security groups of the VPC. |
vSwitchIds | The unique identifier of the vSwitch in the VPC. Separate multiple vSwitch IDs with commas (,). Virtual nodes are generated based on vSwitches. |
selectors | The pod selector. The pod selector can select pods based on namespaces or labels, and automatically add annotations or labels. |
enableClusterIp | Specifies whether to use the ClusterIP. Default value: true. |
enableLogController | Specifies whether to enable the Alibaba Cloud log controller. Default value: false. |
enablePVCController | Specifies whether to enable the persistent volume claim (PVC) controller. Default value: false. |
enablePrivateZone | Specifies whether to enable the service discovery feature of PrivateZone. Default value: false. |
featureGates | Specifies whether to enable feature gates. |
For more information, see Overview of Elastic Container Instance.
Virtual nodes
When you use ACK Serverless clusters, you do not need to manage nodes. To ensure that ACK Serverless clusters are compatible with Kubernetes-native features, you can still find virtual nodes in ACK Serverless clusters. Virtual nodes in ACK Serverless clusters can provide ultra-large computing resources to handle traffic fluctuations. Virtual nodes are generated based on the vSwitchIds parameter in the eci-profile ConfigMap. Virtual nodes do not occupy any computing resources.
Pod configurations
You can customize pods in ACK Serverless clusters by adding annotations to pods. The following table describes the annotations.
The annotations described in the following table are applicable only to the pods that are scheduled to virtual nodes. These pods run on elastic container instances. The annotations cannot be added to the pods that are scheduled to regular nodes.
Add annotations to the
metadatafield of the pods. For example, when you configure a Deployment, add annotations in thespec.template.metadata field.Pod annotations have a higher priority than the settings that correspond to the same feature in the Elastic Container Instance profile.
Annotation | Example | Description | References |
k8s.aliyun.com/eci-security-group | sg-bp1dktddjsg5nktv**** | The ID of the security group. | |
k8s.aliyun.com/eci-vswitch | vsw-bp1xpiowfm5vo8o3c**** | The IDs of the vSwitches. You can specify multiple vSwitches across zones. | Configure multiple zones to create an elastic container instance-based pod |
k8s.aliyun.com/eci-schedule-strategy | vSwitchOrdered | The multi-zone scheduling policy. Valid values:
| |
k8s.aliyun.com/eci-ram-role-name | AliyunECIContainerGroupRole | The Resource Access Management (RAM) role that Elastic Container Instance assumes to access other Alibaba Cloud services. | |
k8s.aliyun.com/eci-use-specs | 2-4Gi,4-8Gi,ecs.c6.xlarge | The specifications of elastic container instances. You can specify multiple specifications, such as the number of CPU cores and the memory size. You can also specify an ECS instance type. | Specify multiple instance specifications to create an elastic container instance |
k8s.aliyun.com/eci-spot-strategy | SpotAsPriceGo | The bidding policy of the preemptible instance. Valid values:
| |
k8s.aliyun.com/eci-spot-price-limit | 0.5 | The highest price of the preemptible instance. Note This parameter is valid only if k8s.aliyun.com/eci-spot-strategy is set to SpotWithPriceLimit. | |
k8s.aliyun.com/eci-cpu-option-core | 2 | The number of physical CPU cores. | |
k8s.aliyun.com/eci-cpu-option-ht | 1 | The number of threads per core. | |
k8s.aliyun.com/eci-reschedule-enable | "true" | Specifies whether to enable the rescheduling feature for elastic container instances. | |
k8s.aliyun.com/pod-fail-on-create-err | "true" | Specifies whether to set the status of the elastic container instances to Failed if pods fail to be created on the elastic container instances. | |
k8s.aliyun.com/eci-image-snapshot-id | imc-2zebxkiifuyzzlhl**** | The ID of the image cache. Note To use an image cache to create an elastic container instance, you can specify the image cache that you want to use or enable automatic matching for image caches. We recommend that you enable automatic matching for image caches. | |
k8s.aliyun.com/eci-image-cache | "true" | Specifies whether to enable automatic matching for image caches. Note To use an image cache to create an elastic container instance, you can specify the image cache that you want to use or enable automatic matching for image caches. We recommend that you enable automatic matching for image caches. | |
k8s.aliyun.com/acr-instance-id | cri-j36zhodptmyq**** | The ID of the Container Registry Enterprise Edition instance. You can specify a Container Registry Enterprise Edition instance that resides in a region different from the region of the elastic container instance. To do this, you must add the region name of the Container Registry Enterprise Edition instance before the ID of the Container Registry Enterprise Edition instance. Example: cn-beijing:cri-j36zhodptmyq****. | Pull images from a Container Registry Enterprise Edition instance without using a secret |
k8s.aliyun.com/eci-eip-instanceid | eip-bp1q5n8cq4p7f6dzu**** | The ID of the elastic IP address (EIP). | |
k8s.aliyun.com/eci-with-eip | "true" | Specifies whether to automatically create an EIP and associate the EIP with the pod. | |
k8s.aliyun.com/eip-bandwidth | 5 | The bandwidth value for the EIP. | |
k8s.aliyun.com/eip-common-bandwidth-package-id | cbwp-2zeukbj916scmj51m**** | The ID of the EIP bandwidth plan. | |
k8s.aliyun.com/eip-isp | BGP | The line type for the EIP. This annotation is applicable only to pay-as-you-go EIPs. Valid values:
| |
k8s.aliyun.com/eip-internet-charge-type | PayByBandwidth | The metering method of the EIP. Valid values:
| |
k8s.aliyun.com/eci-enable-ipv6 | "true" | Specifies whether to assign an IPv6 address to the instance. | Assign an IPv6 address to an Elastic Container Instance-based pod |
k8s.aliyun.com/eci-ipv6-bandwidth-enable | "true" | Specifies whether to enable Internet access to the pod over IPv6 addresses. | |
k8s.aliyun.com/eci-ipv6-bandwidth | 100M | The maximum public bandwidth of the IPv6 address. | |
kubernetes.io/ingress-bandwidth | 40M | The inbound bandwidth. | Limit the inbound and outbound bandwidth of an elastic container instance |
kubernetes.io/egress-bandwidth | 20M | The outbound bandwidth. | |
k8s.aliyun.com/eci-extra-ephemeral-storage | 50Gi | The temporary storage capacity. | |
k8s.aliyun.com/eci-eviction-enable | "true" | Specifies whether to automatically evict pods that do not have sufficient temporary storage space from elastic container instances. | Automatically evict pods whose temporary storage spaces are insufficient |
k8s.aliyun.com/eci-core-pattern | /pod/data/dump/core | The directory in which core dump files are stored. | |
k8s.aliyun.com/eci-ntp-server | 100.100.*.* | The IP address of the Network Time Protocol (NTP) server. | |
k8s.aliyun.com/plain-http-registry | "harbor***.pre.com,192.168.XX.XX:5000,reg***.test.com:80" | The IP address of the self-managed image repository. When you create an elastic container instance by using an image in a self-managed image repository that uses the HTTP protocol, you must specify this parameter. This allows Elastic Container Instance to pull the image over HTTP and prevents image pull failures due to the use of different protocols. | |
k8s.aliyun.com/insecure-registry | "harbor***.pre.com,192.168.XX.XX:5000,reg***.test.com:80" | The domain name of the self-managed image repository. When you create an elastic container instance by using an image in a self-managed image repository that uses a self-signed certificate, you must add this annotation to the instance to skip the certificate authentication. This prevents image pull failures due to certificate authentication failures. |
For more information, see ECI Pod Annotation.
Network management
By default, Elastic Container Instance-based pods use the host network mode. Each pod must be assigned an elastic network interface (ENI) by the vSwitch. This enables communications with the Elastic Compute Service (ECS) instances and ApsaraDB RDS instances in the VPC in which the cluster is deployed.
Item | Description |
Service |
|
Ingress |
|
Service discovery | To use the service discovery feature within a cluster, enable PrivateZone or CoreDNS when you create the cluster. You can also use the ECI profile to enable PrivateZone or install the CoreDNS component from the Add-ons page of the ACK console after the cluster is created. |
EIP | You can associate EIPs with Elastic Container Instance-based pods. You can automatically create an EIP for an Elastic Container Instance-based pod or associate an existing EIP with an Elastic Container Instance-based pod. |
Storage management
You can mount Elastic Block Storage (EBS) or File Storage NAS (NAS) file systems to pods.
Item | Description |
EBS (disks) |
|
NAS |
|
Observability
Item | Description |
Logging | In ACK Serverless clusters, you can modify eci-profile to enable Simple Log Service to collect pod logs. For more information, see the Step 1: Create an application and configure Simple Log Service to collect application log section of the "Collect application logs by using pod environment variables" topic. |
Monitoring | You can install the arms-prometheus component to enable cluster monitoring for an ACK Serverless cluster. For more information, see Enable Managed Service for Prometheus. |
Image management
ACK Serverless clusters allow you to use image caches to accelerate the creation of pods. This reduces the response time of applications. For more information about how to enable the image cache feature for pods, see Use ImageCache to accelerate the creation of pods.
If you want to pull images from Container Registry to create pods in ACK Serverless clusters, you can pull images from a Container Registry Enterprise Edition instance without a using a secret.
Auto scaling
ACK Serverless clusters are nodeless. You do not need to worry about node planning or cluster expansion by using cluster-autoscaler. You need to only scale applications to meet your business requirements. We recommend that you configure Horizontal Pod Autoscaler (HPA) or CronHPA policies to adjust the number of pods on demand. For more information, see Auto scaling overview.
Authorization
If your application pods need to access Alibaba Cloud services, you can configure RAM Roles for Service Accounts (RRSA) to complete authorization.
Cluster management
Item | Description |
Intelligent O&M | You can use the intelligent O&M feature to periodically check the health status of ACK Serverless clusters, or run prechecks on clusters to be upgraded or migrated. |
Updates | You can upgrade ACK Serverless clusters without service interruptions. |
ACK Serverless Pro | ACK Serverless Pro clusters are more reliable, ensure higher service uptime, and allow you to create more pods. |
Migration | You can upgrade trial or old ACK Serverless Basic clusters to ACK Serverless Pro clusters without service interruptions for higher service reliability. |
Component management
ACK Serverless clusters provide a variety of components and extended cluster features. You can deploy, update, or uninstall components based on your business requirements. For more information, see Manage components.
Managed components
To simplify cluster O&M and allow you to focus on application development, ACK Serverless clusters provide managed system components. You can use the following managed system components in ACK Serverless clusters: kube-scheduler, cloud-controller-manager, kube-controller-manager, and kube-apiserver. In addition to these key Kubernetes components, ACK Serverless clusters will provide more managed storage, networks, and monitoring components in the future.
Managed components can create objects such as ClusterRoles, ClusterRoleBindings, ServiceAccounts, Services, and ConfigMaps. However, the objects created by managed components are not deployed on elastic container instances that run in ACK Serverless clusters. To ensure cluster stability, we recommend that you do not modify the objects created by managed components.
Managed components are deployed and maintained by ACK Serverless clusters. You can use the ACK API to interact with the managed components in ACK Serverless clusters. Managed components provide the following benefits:
Save the costs of elastic container instances.
Provide automated deployment and maintenance.
Use high availability architectures.
Application management
You can install Helm charts from the Marketplace page in the ACK console and then manage them on the Helm page. For more information, see Use Helm to simplify application deployment.
Billing rules
ACK Serverless clusters are classified into ACK Serverless Basic clusters and ACK Serverless Pro clusters. The billable items and billing rules vary based on the type of cluster. For more information, see Billing of ACK Serverless clusters.
Limits
ACK Serverless clusters have the following limits:
DaemonSets are not supported. You can replace DaemonSets with sidecar containers.
You cannot specify
HostPathorHostNetworkin podmanifests.Privileged containers are not supported. You can use a security context to add capabilities to a pod.
NoteThe privileged container feature is in internal preview. To use this feature, submit a ticket.
NodePort Services and the Session Affinity feature are not supported.
The China South Finance and Alibaba Gov Cloud regions are not supported.
Contact us
If you have questions about ASK clusters, join the DingTalk group 31544226.