ApsaraDB RDS:Update the minor engine version

For more information about the release notes for minor engine versions of an RDS instance or a serverless RDS instance, see Release notes for AliSQL.

Version status description

• Discontinued: If a minor engine version has known major defects or has expired for more than one year, the minor engine version is discontinued. In this case, the minor engine version is no longer available when you purchase RDS instances.

• Outdated: If the expiration time specified for a minor engine version arrives, the minor engine version is considered outdated. For more information about the expiration time of a minor engine version, see Release notes for AliSQL. If the expiration time of a minor engine version is not specified or does not arrive, the minor engine version is in its lifecycle.

• Stable: All minor engine versions excluding discontinued and outdated minor engine versions are considered stable.

Feature description

• Automatic update: The minor engine version of your RDS instance or serverless RDS instance is automatically updated. You can check the update method of the RDS instance based on the value of the Automated Update of Minor Engine Version parameter on the Basic Information page. If the minor engine version of the RDS instance is not the latest version, the system automatically delivers active O&M tasks to update the minor engine version at irregular intervals. The system automatically updates the minor engine version of the RDS instance within the maintenance window that you specified. For more information, see Configure a maintenance window.

  Note

  The system notifies you of the tasks by using methods such as text messages and emails. If you want to receive the notifications, you must log on to the Message Center console, select ApsaraDB Fault or Maintenance Notifications, and then configure the contact information.

• Manual update: The system does not automatically deliver active O&M tasks to update the minor engine version of your RDS instance. If you do not want to receive the notifications of minor version updates, you can go to the Basic Information page of the RDS instance and change the value of the Automated Update of Minor Engine Version parameter to Manual Upgrade. If you do not update the minor engine version of your RDS instance for a long period of time, the system notifies you of updating the minor engine version at irregular intervals. If you receive the notifications, we recommend that you update the minor engine version of the RDS instance at the earliest opportunity.

  Note

  The notifications are sent to you by using methods such as text messages. If you want to receive the notifications, you must log on to the Message Center console, select Notifications about product upgrades, configuration changes, and price changes, and then configure the contact information.

Impacts

A 30-second transient connection may occur during the update of minor engine versions.

The system automatically updates the minor engine version of your RDS instance within the maintenance window that you specified. You can go to the Basic Information page of your RDS instance to change the maintenance window.

We recommend that you perform manual updates during off-peak hours or modify the code of your application for the application to automatically reconnect to your RDS instance.

Usage notes

• If the minor engine version of your RDS instance is outdated, the RDS instance may encounter risks such as service interruptions and data loss. We recommend that you update the minor engine versions of your RDS instances on a regular basis or immediately after you receive O&M notifications from Alibaba Cloud.

• If a read-only RDS instance is attached to your primary RDS instance and the minor engine version of the read-only RDS instance is earlier than the new minor engine version, the system updates the minor engine version of the read-only RDS instance and then updates the minor engine version of the primary RDS instance.

• If the minor engine version of an RDS instance is discontinued or is not in the maintenance list, the system updates the minor engine version to the latest version when the RDS instance is upgraded, the specifications of the RDS instance is changed, or Alibaba Cloud upgrades the hardware for the instance.

• After you update the minor engine version of your RDS instance, you cannot roll the minor engine version back to the previous version.

• After you update the minor engine version of an RDS instance or a serverless RDS instance, the value of the Backup Usage parameter on the Basic Information page of the instance may be 0. After the next scheduled backup is complete, the actual value of the Backup Usage parameter is displayed.

• The system does not deliver O&M tasks to update the minor engine versions of newly created RDS instances. If you want to update the minor engine version of a newly created RDS instance to the latest version, you can go to the Basic Information page of the RDS instance. For more information, see Update the minor engine version.

• After you start an update task, you cannot cancel the task. If the update fails, all changes are rolled back and the major engine version and metadata of the RDS instance remain unchanged.

• If a minor engine version meets the requirements to be discontinued, the minor engine version is discontinued even if the lifecycle of the minor engine version does not end.

Configure the method to update the minor engine version

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Configuration Information section of the Basic Information page, click Settings to the right of Automated Update of Minor Engine Version.

3. Select Automatic Upgrade or Manual Upgrade and click OK.

Configure the manual update to the minor engine version

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Configuration Information section, click Update Minor Engine Version.

   Note

   If you cannot find Update Minor Engine Version, the in-use minor engine version is the latest version.

3. In the dialog box that appears, configure the Latest Version and Upgrade Time parameters, and click OK.

FAQ

• After I update the minor engine version of my RDS instance, why does the SELECT @@version statement still return the minor engine version that I used before the update?

  The SELECT @@version statement returns the kernel engine version of MySQL. To view the version of AliSQL, you must run the show variables like '%rds_release_date%' command.

• Do I update the minor engine version of my RDS instance only to the next minor engine version?

  You can update the minor engine version of your RDS instance to any new minor engine version that is available in the ApsaraDB RDS console.

• Why does a transient connection occur during the update? Does the update cause other serious risks?

  Before the system updates the minor engine version of your primary RDS instance, the system updates the minor engine version of the secondary RDS instance. After the minor engine version of the secondary RDS instance is updated, the system switches your workloads over to the secondary RDS instance. During the switchover, a transient connection that lasts approximately 30 seconds occurs. The update does not cause other serious risks.

• Does the update cause incompatibility issues?

  Yes, after you update the minor engine version of your RDS instance to 20210930 or later, compatibility issues related to PHP may occur. For more information, see PHP compatibility issues. If a compatibility issue related to PHP occurs, reconnect to the RDS instance to resolve the issue.

• Will I experience inconsistent database behaviors after I update the minor engine version of my RDS instance?

  Yes, you may experience inconsistent database behaviors after you update the minor engine version of your RDS instance. For example, when you update the minor engine version to MySQL 8.0.19, the widths field of the integer type is deprecated. For more information, see MySQL official documentation. The inconsistent database behaviors caused by a minor engine version update are subject to open source MySQL.

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