Container Service for Kubernetes (ACK) provides container-centric solutions based on open source Kubernetes. As new Kubernetes versions are released, the list of Kubernetes versions supported by ACK also changes. New Kubernetes versions are added to the list and outdated Kubernetes versions are discontinued. This topic describes how ACK supports different Kubernetes versions, including the release cycle, support policies, and risks of using outdated Kubernetes versions.
To avoid security and stability risks associated with outdated cluster versions, and to enjoy the latest features and improved technical support, we recommend that you upgrade your cluster version in a timely manner. Make sure to fully understand the feature changes and precautions of each version before you upgrade.
For more information about how to manually update the control plane of the cluster and/or node pools, see Manually upgrade ACK clusters.
For more information about how to automatically update the cluster control plane and/or node pools to reduce your O&M work, see Automatically upgrade a cluster.
Release notes
The following table describes the Kubernetes versions that are supported by ACK clusters and ACK Serverless clusters.
In version 1.31 and later, ACK provides support for all Kubernetes versions for one year.
Version | Status | Release date (ACK) | Discontinue date (ACK) |
Released | September 2024 | September 2025 | |
Released | June 2024 | June 2026 | |
Released | October 2023 | October 2025 | |
Released | April 2023 | April 2025 |
Release cycle
After the Kubernetes community releases a new minor version, ACK performs a risk assessment and consistency test on the version. You can create clusters of the new version and upgrade existing clusters to the new version after the new Kubernetes version passes the tests. In most cases, the preparations take two weeks and the duration varies based on the differences between versions.
After the Kubernetes community releases a new patch version for a minor version, ACK determines whether to release the patch version based on the risk level of the issue fixed by the patch version. In most cases, ACK requires about 24 hours to perform a risk assessment and consistency test on a patch version that fixes critical issues, such as high-risk security vulnerabilities. Then, ACK allows you to create clusters of the new version and upgrade existing clusters to the new version.
Version description
The Kubernetes versions supported by ACK follow the semantic versioning scheme in the x.y.z-aliyun.n format. x.y.z is the open source Kubernetes version. x is the major version, y is the minor version, z is the patch version, and n is the ACK patch version. For example, version 1.31.1-aliyun.1 is based on open source Kubernetes 1.31.1. For more information about Kubernetes versions, see Kubernetes Release Versioning.
Rules for supporting Kubernetes versions
Cluster creation
ACK allows you to create clusters of the latest three minor versions. For example, the latest minor versions are Kubernetes 1.28, 1.30, and 1.31. When ACK starts to support Kubernetes 1.31, Kubernetes 1.26 is discontinued and you can no longer create clusters of Kubernetes 1.26. In addition, the outdated patch version is no longer available.
Cluster upgrade
ACK allows you to upgrade ACK clusters from a minor version to the following minor version. You cannot skip minor versions when you upgrade ACK clusters or roll back your ACK clusters to an earlier version. For example, if your cluster runs Kubernetes 1.28 and you want to upgrade the cluster to Kubernetes 1.31, you need to first upgrade the cluster to Kubernetes 1.30 and then to Kubernetes 1.31.
ACK allows you to upgrade an ACK cluster only to the latest patch version. You cannot upgrade your cluster to outdated patch versions.
Technical support
For maintained versions, the technical support provided by ACK includes consultations, online tutorials, and troubleshooting.
Risks of discontinued Kubernetes versions
Security and stability risks may arise if your ACK clusters run a discontinued Kubernetes version. Once a cluster version reaches its end-of-life, you will no longer have access to new features introduced in subsequent Kubernetes releases, nor will you receive timely and effective technical support.
Furthermore, to ensure availability and security, ACK reserves the right to forcibly upgrade clusters running on outdated Kubernetes versions. ACK will send notifications by text messages, emails, and internal messages at least one month prior to the scheduled upgrade. Pay attention to these notifications and prepare for the upgrade.