You may deploy multiple Kubernetes clusters across different regions in the cloud or on the premises. You can register external clusters in the Alibaba Cloud Container Service for Kubernetes (ACK) console. This allows you to manage multiple clusters in the console and reduce operations and maintenance costs. This topic describes the features and associated resources supported by registered clusters.
Benefits of registered clusters
In some scenarios, you can deploy multiple clusters across different regions in the cloud and on the premises. The observability of these clusters may vary, depending on the implementations of cluster auditing, log collection, and monitoring and alerts. In this case, the different levels of observability may make changes to your applications in the clusters. As a result, centralized management of clusters has been a demanding task.
To solve this issue, you can register external clusters in the ACK console and manage these clusters in the console.
Comparison of features between registered clusters and ACK clusters
|Category||Feature||ACK cluster||Registered cluster|
|Access to clusters||Uses kubectl and kubeconfig files to access clusters.||✔️||✔️|
|Uses the console to access clusters.||✔️||✔️|
|Core features||Manages namespaces.||✔️||✔️|
|Manages persistent volumes and storage classes.||✔️
Supports cloud disks, local disks, Network Attached Storage (NAS), Cloud Paralleled File System (CPFS), and Object Storage Service (OSS).
The supported storage types vary, depending on the environments in which registered clusters run.
|Manages network policies.||✔️
Supports the Terway network plug-in.
The network policies vary, depending on the environments in which registered clusters run.
|Manages role-based access control (RBAC).||✔️||✔️|
|Manages pod security policies.||✔️||✔️|
|Manages resource quotas.||✔️||✔️|
|Manages custom resource definitions (CRDs).||✔️||✔️|
|Supports horizontal pod autoscaling (HPA).||✔️||✔️|
|Supports pod runtime classes.||✔️
Supports only sandboxed containers.
|Supports Elastic Container Instances (ECIs).||✔️||✔️
For more information about the configurations, see Connect a virtual node to a registered external cluster.
|Application management||Deploys and manages applications that you create by using Helm charts.||✔️||✔️|
|Supports the GitOps-based application delivery chain.||✔️||N/A
Will support this feature soon.
|Supports the Knative add-on.||✔️||✔️|
|Supports the Istio add-on.||✔️||✔️|
|Supports the fully-managed service mesh platform Alibaba Cloud Service Mesh (ASM).||✔️||✔️|
|Security service||Supports Resource Access Management (RAM)-based authentication and RBAC-based authorization.||✔️||✔️|
|Supports cluster auditing based on Log Service.||✔️||✔️|
|Supports Security Center.||✔️||N/A|
|Observability||Supports the Event Center that enables the node-problem-detector (NPD) add-on.||✔️||✔️
For more information about the configurations, see Create and use a Kubernetes event center.
|Supports Ingress charts.||✔️||✔️
For more information about the configurations, see Analyze logs of Ingress to monitor access to Ingress.
|Supports log collection.||✔️||✔️
For more information about the configurations, see Enable Log Service in an external cluster.
|Supports Application Real-Time Monitoring Service (ARMS).||✔️||✔️
For more information about the configurations, see Enable ARMS for registered external clusters.
|Supports ARMS Prometheus monitoring.||✔️||✔️
For more information about the configurations, see Enable arms-prometheus in an external cluster.
|Supports architecture characteristics discovery provided by Application High Availability Service (AHAS)||✔️||✔️
|Supports application throttling provided by AHAS.||✔️||✔️
|Supports the NPD add-on.||✔️||✔️
For more information about the configurations, see Enable node-problem-detector in an external cluster.
|Supports the metrics adapter feature enabled by alibaba-cloud-metrics-adapter add-on.||✔️||✔️
For more information about the configurations, see Deploy a metric adapter to an external cluster.
|Integrates with CloudMonitor.||✔️||N/A|
|Integrates with Key Management Service (KMS).||✔️||N/A|
|Manages lifecycle rules.||Manages nodes.||✔️||✔️|
|Manages node pools.||✔️||N/A|
|Supports cluster auto scaling.||✔️||✔️
Support for this feature varies, depending on the environments in which registered clusters run.
|Supports certificate rotation.||✔️||N/A|
|Supports cluster upgrades.||✔️||N/A|
|Manages system components.||✔️||N/A|
|Supports cluster checks.||✔️||N/A|
A registered cluster can also be associated with other services that are charged based on the specific features.
For more information about how to register clusters, see Register a cluster.