Upgrade the minor engine version

Considerations

• If the target cluster is an Enterprise Edition cluster or a Community-Compatible Edition cluster purchased after December 1, 2021, it supports minor engine version upgrades. Requirements

• Service impact during an upgrade:

  • Community-Compatible Edition: The upgrade process restarts the cluster, which causes a service interruption of 1 to 5 minutes. This is an average estimate. The actual duration may be significantly longer depending on the number of parts and the cold storage in your cluster. We recommend that you check the duration of recent cluster restarts for a better estimate. Perform the upgrade during off-peak hours and ensure that your application has an automatic reconnection mechanism.

  • Enterprise Edition: The process restarts the nodes in the cluster in batches. This ensures that at least half of the nodes are available to serve requests at all times during the upgrade.

• When a new minor engine version is released, Alibaba Cloud ClickHouse sends a notification to the contacts associated with your Alibaba Cloud account. We recommend that you upgrade to the latest version promptly. If you fail to upgrade within six months of receiving the notification, you are responsible for any resulting business interruptions, data loss, or other consequences.

• You cannot downgrade a minor engine version after an upgrade. For Enterprise Edition, if you need to roll back a minor engine version upgrade (for example, from 24.12.1 to 24.12.2), submit a ticket to contact technical support.

• When you upgrade an Enterprise Edition cluster to version 25.10 or later for the first time, the system automatically creates a default_role role and grants the role to all existing users. The default_role role is also automatically granted to newly created regular users to ensure that permissions are not regressed during version upgrades.

  Note

  New minor engine versions may introduce more granular permission controls. To ensure a smooth upgrade, the system grants newly added permission checkpoints to the default_role role.

  If the permissions granted to default_role exceed what a user requires, you can revoke the role by running the REVOKE command. However, revoking the role may cause query errors due to missing permissions after subsequent version upgrades.

  If you find that a user has not been granted the default_role role, you can manually grant it by using a privileged account.

• During a minor engine version upgrade, you can only view cluster information. You cannot upgrade the cluster specifications, scale out, scale in, restart the cluster, or modify parameter configurations.

• If an asterisk (*) appears next to Minor Version in the Alibaba Cloud ClickHouse console, the current version does not support minor engine version upgrades.

Upgrade the minor engine version

1. Log on to the Alibaba Cloud ClickHouse console.

2. In the upper-left corner, select the region where your target cluster is located.

3. On the Clusters page, click the ID of the target cluster to open the Cluster Information page.

4. In the Configuration Information section, click Minor Version Upgrade on Kernel next to Minor Version.

   Note

   If The current version is the latest version appears next to Minor Version, you do not need to upgrade the minor engine version.

5. In the Minor Version Upgrade dialog box, select an Latest Version and an Upgrade Time, and then click OK.

   Note

   The upgrade process takes about 10 minutes. The upgrade is complete when the cluster status changes to Running.