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Hologres:Set a maintenance window

Last Updated:Feb 04, 2026

To ensure the stability of your Hologres instance, Hologres performs scheduled maintenance operations to fix critical bugs and security issues. These operations include instance version upgrades, hardware upgrades, and network upgrades. This topic describes how to set a maintenance window and explains related events.

Precautions

  • If you enable automatic minor version upgrades, Hologres upgrades the minor version of your instance during the specified maintenance window. Queries may fail during the upgrade. We recommend setting the maintenance window to off-peak hours to minimize the impact on your business.

  • The default maintenance window is 21:00-22:00 (Asia/Shanghai UTC+8). We recommend setting the maintenance window to off-peak hours to minimize the potential impact on your business.

  • You cannot configure a separate maintenance window or automatic minor version upgrade policy for read-only secondary instances. They inherit these settings from the primary instance.

Configure O&M event notifications

  • When Hologres needs to perform a maintenance event, you are typically notified at least three days in advance. Notifications are sent by text message, voice call, email, internal message, or through the console. For urgent events that address critical risks, notifications may be sent less than three days in advance because the fix must be applied as soon as possible.

  • Log on to the Message Center. On the Basic Receiving Management page, ensure that the Product O&M Notification switch is enabled and set the message recipients. Add your Hologres maintenance engineers as recipients. Otherwise, you will not receive notifications.

Modify the maintenance window for a single instance

  1. Go to the Hologres instance list. In the top menu bar, select a region in the upper-left corner, and then click the ID of the target instance.

  2. On the Instance Details page, in the Basic Information section, click Settings next to Maintainable Time Window.

  3. In the Configure Maintainable Time Window dialog box, select a maintenance window and click Settings.

Enable the automatic minor version upgrade policy

  1. Go to the Hologres instance list. In the top menu bar, select a region in the upper-left corner, and then click the ID of the target instance.

  2. On the Instance Details page, in the Basic Information section, click the switch next to Minor Version Auto Upgrade.

  3. In the Enable Minor Version Auto Upgrade dialog box, click Enable.

Disable the automatic minor version upgrade policy

  1. Go to the Hologres instance list. In the top menu bar, select a region in the upper-left corner, and then click the ID of the target instance.

  2. On the Instance Details page, in the Basic Information section, click the switch next to Minor Version Auto Upgrade.

  3. In the Disable Minor Version Auto Upgrade dialog box, click Disable.

Event descriptions

The following table describes the backend operations that may be performed during the maintenance window and their potential impacts.

Event cause

Impact type

Impact description

Instance restart

Brief instance interruption

During the operation, the following impacts occur:

  • The instance connection is typically disconnected for 5 to 10 minutes. For instances with many tables or table files, the transient disconnection during a standard upgrade may exceed 10 minutes. Perform this operation during off-peak hours and make sure your application has a reconnection mechanism.

  • If a standard upgrade is required, note the differences between the versions and select a suitable upgrade time based on your business needs.

Hot upgrade

Transient instance disconnection

During the operation, the following impacts occur:

  • The instance experiences a transient connection disconnection and enters a read-only state for up to 10 minutes to wait for full data synchronization. Set the maintenance window to off-peak hours and make sure your application has a reconnection mechanism.

  • The use of the instance in DataWorks and Flink is briefly affected. Normal operations resume automatically after the upgrade is complete.

Differences between minor versions

The content updated varies between minor versions. Note the differences between the new minor version and the current one.

Standard upgrade

Brief instance interruption

During the operation, the following impacts occur:

  • The instance connection is typically disconnected for 5 to 10 minutes. For instances with many tables or table files, the transient disconnection during a standard upgrade may exceed 10 minutes. Perform this operation during off-peak hours and make sure your application has a reconnection mechanism.

  • If a standard upgrade is required, note the differences between the versions and select a suitable upgrade time based on your business needs.