Maintenance windows

The Control Center provides two features, maintenance windows and maintenance events, to help you manage the time frames and event records for the platform's planned changes to resources in your project space.

Overview

In a fully-managed serverless architecture, planned maintenance on the underlying infrastructure, such as system upgrades, node rotation, and hot migration, can cause brief failovers for running jobs. You can use the Control Center to restrict these planned changes to specific maintenance windows. This feature postpones changes scheduled during peak business hours, reducing the impact of disruptions on your services.

Maintenance window: A time frame that you define for the platform to perform changes on underlying resources. During a maintenance window, the platform can perform operations such as seamless migration and node rotation. Outside this window, all planned changes are automatically postponed until the next maintenance window.
Maintenance events: A centralized log of planned maintenance operations initiated by the platform, including ECS instance maintenance, node rotation, and host machine hot migration. This feature provides a full lifecycle view of each event, enabling post-event auditing and review.

Note

Maintenance windows apply at the project space level, affecting all resources within that space.
If no maintenance windows are configured, the platform uses a default policy: it can perform changes daily from 02:00 to 06:00 (UTC+8).

Prerequisites

You have activated Realtime Compute for Apache Flink. For more information, see Activate Realtime Compute for Apache Flink.
You have Owner or Admin permissions for the target project space.

Create maintenance window

In the navigation pane on the left, click Control Center.
On the Maintenance Windows tab, click Create Maintenance Window.

Configure the following parameters.

Parameter	Description
Window name	The name of the maintenance window. The name must be 2 to 200 characters long and can contain Chinese characters, letters, digits, and the following special characters: `-._`.
Resource scope	The scope affected by the maintenance window. Currently, only All (project space-level) is supported, which means the window applies to all resources in the current project space.
Recurrence	The frequency of the maintenance window. You can select Daily, Weekly, or Monthly. If you select Weekly, you must specify the days of the week. If you select Monthly, you must specify the dates of the month. If a selected date does not exist in a given month (for example, the 31st), the window is not active for that month.
Time range (UTC)	The start and end time for each maintenance window, specified in UTC. The console also displays the corresponding local time (UTC+08:00) for your reference. Note Each window must be at least one hour long. Cross-day windows (for example, 23:00 to 01:00) are supported. For monthly recurrence, you must select at least five maintenance days each month. The interval between any two consecutive maintenance days cannot exceed seven days, including across months.
Enable	Specifies whether to activate the maintenance window immediately. If enabled, the window takes effect as soon as you save the configuration. If disabled, the configuration is saved but remains inactive until you enable it later.

Click OK.

Manage maintenance windows

In the list of maintenance windows, you can view the name, resource scope, time range, and status of each window. You can also perform the following actions:

Details: View the complete configuration details of the maintenance window and its associated maintenance event history.
Edit: Modify the name, time range, or enabled status of the window.
Delete: Delete the maintenance window. After deletion, the platform is no longer constrained by this window. If all custom windows are deleted, the system reverts to the default platform policy (02:00 to 06:00 daily, UTC+8).

Note

If the current time is outside all active maintenance windows, a notification appears at the top of the page, indicating that all planned changes have been postponed until the next window.

Maintenance events

Switch to the Maintenance Events tab to view planned maintenance events that have occurred or are scheduled to occur within the last 30 days.

Event list

Parameter	Description
Event name	The name of the underlying engine maintenance event.
Event type	The source of the event, such as Flink maintenance, planned ECS maintenance, or unexpected ECS instance downtime.
Trigger time	The time the event is scheduled to occur or has actually occurred.
Event status	The current status of the event. Valid states include: Completed (The maintenance was successful, and the job has recovered), Scheduled (The event is scheduled and pending execution), Postponed (The event occurred outside a maintenance window and has been postponed to the next one), and Manual Intervention Required (The maintenance failed or timed out, requiring a manual job restart).
Affected jobs	The number of jobs affected by the event. Click the number to view a list of specific jobs and their recovery status.

Event details

Click View Details for an event in the list to see the following information:

Basic information: Event source, scheduled execution period, and trigger time.
Window matching status: Indicates whether the event occurred within a configured maintenance window.
Affected job analysis: A list of affected jobs and their current status.
Event history: The complete lifecycle log of the event.

Maintenance event notifications

You can configure alert notifications to receive alerts for important maintenance events.

Standard notifications: Sent when the status of a maintenance event changes, such as when it is about to start, completed, or postponed.
Forced change notifications: When a maintenance event does not fall within any maintenance window and less than 24 hours remain before its final execution deadline, the platform forces the change and sends a notification through a console pop-up and a top banner.

FAQ

What happens if multiple maintenance windows overlap?
If windows overlap, the platform can perform maintenance during the entire combined time range.
Why was a change postponed?
When a planned maintenance event is scheduled outside all configured maintenance windows, the system automatically postpones the change until the next available window. You can view postponed events on the Maintenance Events tab, where their status is marked as Postponed.
Do maintenance windows support job-level control?
Currently, maintenance windows can only be set at the project space level. Granular, job-level control will be supported in a future release.
How do cross-day maintenance windows work?
The system treats this as a continuous period from 23:00 on the specified day to 01:00 on the following day.