Hologres runs scheduled maintenance — version, hardware, and network upgrades — to address critical bugs and security issues, which may briefly interrupt connections. Set a maintenance window during off-peak hours to minimize disruption.
Before you begin
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The default maintenance window is
21:00-22:00 (Asia/Shanghai UTC+8). -
If automatic minor version upgrades are enabled, Hologres upgrades your instance's minor version during the maintenance window. Queries may fail during the upgrade.
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Read-only secondary instances inherit the maintenance window and upgrade policy from the primary instance and cannot be configured separately.
Modify the maintenance window
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Go to the Hologres instance list. Select a region from the top navigation bar and click the target instance ID.
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On the Instance Details page, in the Version Information section, click Settings next to Maintenance Window.
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In the Set Maintenance Window dialog box, select a maintenance window and click Settings.
Enable or disable automatic minor version upgrades
When enabled, Hologres automatically upgrades your instance to the latest minor version during the maintenance window. Review the release notes before enabling this feature.
Enable automatic minor version upgrades
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Go to the Hologres instance list. Select a region from the top navigation bar and click the target instance ID.
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On the Instance Details page, in the Version Information section, click the switch next to Minor Version Auto Upgrade.
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In the Enable Minor Version Auto Upgrade dialog box, click Enable.
Disable automatic minor version upgrades
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Go to the Hologres instance list. Select a region from the top navigation bar and click the target instance ID.
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On the Instance Details page, in the Version Information section, click the switch next to Minor Version Auto Upgrade.
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In the Disable Minor Version Auto Upgrade dialog box, click Disable.
Set up O&M event notifications
Hologres typically sends notifications at least three days before scheduled maintenance through text messages, voice calls, email, internal messages, and console alerts. Urgent events may have shorter notice periods.
To receive these notifications:
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Log on to the Message Center.
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On the Common Settings page, make sure that the Product operation notifications checkboxes are selected.
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Add your Hologres maintenance engineers as message recipients.
If Product operation notifications is not selected or your engineers are not listed as recipients, notifications will not be delivered.
Maintenance event types
The following table lists operations that may occur during the maintenance window.
|
Event |
Impact |
Details |
|
Instance restart |
Transient disconnection |
Connections typically drop for 5-10 minutes, or longer for instances with many tables or table files. If a standard upgrade is required, review version differences and choose a suitable time. Ensure your application has a reconnection mechanism. |
|
Hot upgrade |
Transient disconnection |
The instance briefly disconnects and enters a read-only state for up to 10 minutes during data synchronization. DataWorks and Realtime Compute for Apache Flink integrations are briefly affected but resume automatically. Schedule the maintenance window during off-peak hours and ensure your application has a reconnection mechanism. |
|
Standard upgrade |
Brief interruption |
Connections typically drop for 5-10 minutes, or longer for instances with many tables or table files. Review the differences between current and target versions, and choose a suitable upgrade time. Ensure your application has a reconnection mechanism. |
|
Minor version differences |
Varies |
Feature and behavior changes vary between minor versions. Review the release notes to understand what has changed. |
FAQ
How should I prepare for a maintenance event?
Schedule the maintenance window during off-peak hours and ensure all applications connecting to Hologres have a reconnection mechanism.
Do read-only secondary instances have their own maintenance window?
No. Read-only secondary instances inherit the maintenance window and automatic minor version upgrade policy from the primary instance.
How far in advance will I be notified?
Typically at least three days before the event. Urgent events may have shorter notice periods.
What is the difference between a hot upgrade and a standard upgrade?
A hot upgrade causes a brief disconnection and puts the instance into read-only mode for up to 10 minutes during data synchronization. A standard upgrade disconnects the instance for 5-10 minutes, longer for instances with many tables or table files. Both require a reconnection mechanism.