After you enable auto updates for a Container Service for Kubernetes (ACK) managed cluster, the Kubernetes version of the cluster is automatically updated on a regular basis. This simplifies your O&M work. After you configure an auto update policy, the system automatically generates an update schedule in advance, and runs a precheck and updates the control planes of the cluster within the maintenance window of the cluster. This allows you to focus on application development.
Limits
You can enable auto updates only for ACK managed clusters that run Kubernetes 1.20 or later.
Benefits of auto updates
ACK stops releasing new features, feature patches, or security patches for ACK managed clusters that run outdated Kubernetes versions. ACK only provides limited technical support for these Kubernetes versions. For more information, see Risks of outdated Kubernetes versions. To ensure security and stability, we recommend that you use the Kubernetes versions supported by ACK.
Auto updates simplify your O&M work. After you enable auto updates for your cluster, ACK updates the Kubernetes version of your cluster to a later version supported by ACK on a regular basis. This allows you to use the new features provided by the new Kubernetes version.
Auto update policies
After you configure an auto update policy for your cluster, ACK automatically generates an update schedule based on the policy and the Kubernetes versions supported by the ACK managed cluster. ACK runs update tasks in the cluster within the maintenance window specified in the update schedule. You can configure the maintenance window and update frequency in an auto update policy. After you enable auto updates for a cluster, ACK does not immediately update the cluster. If you require an immediate update, we recommend that you manually update the cluster. For more information, see Manually update ACK clusters.
ACK uses the same procedure to update a cluster, regardless of whether the cluster is automatically updated or manually updated. You can manually update a cluster after you enable auto updates for the cluster.
You cannot roll back manual updates or auto updates. For more information about the precautions for manual updates, see Manually update a cluster.
Maintenance window
You can specify a maintenance window for each cluster. The maintenance window is applied in the auto updates of a cluster and the auto O&M of managed node pools in the cluster. ACK automatically generates an update scheduled based on the specified maintenance window and then runs a precheck and update tasks within the maintenance window.
If you modify the maintenance window before the update schedule is implemented, ACK cancels the orchestrated schedule. If you modify the maintenance window when a cluster is being updated, the update process will be cancelled.
To ensure a sufficient time for cluster updates, we recommend that you set the maintenance window to at least 2 hours.
Update frequency
You can select different update frequencies based on your business requirements.
For example, if your current cluster is version 1.26.3-aliyun.1, the latest version is 1.30, and the second-latest version is 1.28, you can update to the following three versions: 1.26.15-aliyun.1, 1.28.9-aliyun.1, and 1.30.1-aliyun.1. The following table describes the update frequency and the specific version to which your cluster will automatically upgrade under different frequencies.
Update frequency | Description | New update version |
Latest Patch Version (patch) | If a patch version is available for the current minor version, the cluster is automatically updated to the patch version. The new Kubernetes version does not contain breaking changes. | 1.26.15-aliyun.1 |
Second-Latest Minor Version (stable) | Automatically update to the latest patch version of the second-latest minor version. The new Kubernetes version may involve changes in APIs and features, but its stability is verified. | 1.28.9-aliyun.1 |
Latest Minor Version (rapid) | Automatically update to the latest patch version of the latest minor version to quickly obtain new features provided by the Kubernetes community. | 1.30.1-aliyun.1 |
For more information about patch versions and minor versions, see Version description.
Update schedule
After you configure an update policy for a cluster, ACK automatically checks whether the cluster can be updated based on the policy and the Kubernetes versions supported by ACK. If the cluster meets the requirements, ACK generates an update schedule at least one day before ACK implements the schedule. You can view the schedule in the ACK console or by calling API operations. You can manually cancel the schedule on demand. The auto update feature is not disabled after you cancel an update schedule of a cluster. After you cancel an update schedule for an ACK managed cluster, ACK can still run update tasks within the maintenance window of the cluster.
After you configure an auto update policy for a cluster, ACK does not immediately update the cluster. ACK checks the overall scheduling policy and generates an update schedule accordingly. After an update schedule is generated, ACK waits for a certain period of time and then runs update tasks in batches. After an update schedule is generated, you can view the schedule by calling the ListOperationPlans API. You can also go to the cluster details page in the ACK console, and then view the schedule under the O&M Tasks tab.
The purpose of update prechecks is to verify the compatibility between the new Kubernetes version and the Kubernetes API server and cluster components. If the cluster fails a precheck, you must fix the issues. After the issues are fixed, ACK runs a precheck again. You can view the details of precheck failures in the History section of the Upgrade Cluster page.
Update notifications
After the update process of an ACK managed cluster is completed, the cluster notifies you of the result (success of failure) by text message.
Enable auto updates
After you enable auto updates for an ACK managed cluster, ACK checks the overall scheduling policy and then runs update tasks within a maintenance window.
Log on to the ACK console. In the left-side navigation pane, click Clusters.
On the Clusters page, find the cluster that you want to manage and click its name. In the left-side pane, choose .
On the Upgrade Cluster page, configure the auto update policy and the maintenance window based on the instructions in the Auto update policies section.
ACK performs a precheck before running auto update tasks. If your cluster fails a precheck, you must fix the issues based on the details displayed on the Upgrade Cluster page. You can view precheck details, update status, and update task details in the History section of the Upgrade Cluster page.
You can manually cancel the schedule on demand.
(Optional) After an update is completed, you can check the Kubernetes version of the cluster on the Clusters page to confirm that the update is successful.
References
If auto updates cannot meet your requirements, you can use the following methods to manually upgrade your cluster:
Use the ACK console: Manually update a cluster.
Use the ACK API: UpgradeCluster.
If you use ACK Basic clusters to run large-scale services in production environments, we recommend that you perform hot migration from the ACK Basic clusters to ACK Pro clusters. For more information, see Hot migration from ACK Basic clusters to ACK Pro clusters.
If you have existing ACK dedicated clusters and want to use the features of ACK Pro clusters, such as control plane management, you can perform a hot migration from the ACK dedicated clusters to ACK Pro clusters. For more information, see Hot migration from ACK dedicated clusters to ACK Pro clusters.
For more information about the Kubernetes versions supported by an ACK managed cluster and the version list update cycle, see Support for Kubernetes versions. In this topic, you can also view the description, update notes, new features, deprecated features, and deprecated APIs of each Kubernetes version.