Use maintenance schedules to manage service updates and maintenance
Maintenance schedules are now available in all Azure SQL Data Warehouse regions. The maintenance schedule feature integrates the Service Health Planned Maintenance Notifications, Resource Health Check Monitor, and the Azure SQL Data Warehouse maintenance scheduling service.
You use maintenance scheduling to choose a time window when it's convenient to receive new features, upgrades, and patches. You choose a primary and a secondary maintenance window within a seven-day period. To use this feature you will need to identify a primary and secondary window within separate day ranges.
For example, you can schedule a primary window of Saturday 22:00 to Sunday 01:00, and then schedule a secondary window of Wednesday 19:00 to 22:00. If SQL Data Warehouse can't perform maintenance during your primary maintenance window, it will try the maintenance again during your secondary maintenance window. Service maintenance could occur during both the primary and secondary windows. To ensure rapid completion of all maintenance operations, DW400(c) and lower data warehouse tiers could complete maintenance outside of a designated maintenance window.
All newly created Azure SQL Data Warehouse instances will have a system-defined maintenance schedule applied during deployment. The schedule can be edited as soon as deployment is complete.
Each maintenance window can be between three and eight hours. Maintenance can occur at any time within the window. When maintenance starts, all active sessions will be canceled and Non-committed transactions will be rolled back. You should expect multiple brief losses in connectivity as the service deploys new code to your data warehouse. You'll be notified immediately after your data warehouse maintenance is completed.
All maintenance operations should finish within the scheduled maintenance windows. No maintenance will take place outside the specified maintenance windows without prior notification. If your data warehouse is paused during a scheduled maintenance, it will be updated during the resume operation.
Alerts and monitoring
Integration with Service Health notifications and the Resource Health Check Monitor allows customers to stay informed of impending maintenance activity. The new automation takes advantage of Azure Monitor. You can decide how you want to be notified of impending maintenance events. Also, you can choose which automated flows will help you manage downtime and minimize operational impact.
A 24-hour advance notification precedes all maintenance events that aren't for the DWC400c and lower tiers. To minimize instance downtime, make sure that your data warehouse has no long-running transactions before your chosen maintenance period.
In the event we are required to deploy a time critical update, advanced notification times may be significantly reduced.
If you received an advance notification that maintenance will take place, but SQL Data Warehouse can't perform maintenance during that time, you'll receive a cancellation notification. Maintenance will then resume during the next scheduled maintenance period.
All active maintenance events appear in the Service Health - Planned Maintenance section. The Service Health history includes a full record of past events. You can monitor maintenance via the Azure Service Health check portal dashboard during an active event.
Maintenance schedule availability
Even if maintenance scheduling isn't available in your selected region, you can view and edit your maintenance schedule at any time. When maintenance scheduling becomes available in your region, the identified schedule will immediately become active on your data warehouse.
View a maintenance schedule
By default, all newly created Azure SQL Data Warehouse instances have an eight-hour primary and secondary maintenance window applied during deployment. As indicated above, you can change the windows as soon deployment is complete. No maintenance will take place outside the specified maintenance windows without prior notification.
To view the maintenance schedule that has been applied to your data warehouse, complete the following steps:
- Sign in to the Azure portal.
- Select the data warehouse that you want to view.
- The selected data warehouse opens on the overview blade. The maintenance schedule that's applied to the data warehouse appears below Maintenance schedule.
Change a maintenance schedule
A maintenance schedule can be updated or changed at any time. If the selected instance is going through an active maintenance cycle, the settings will be saved. They'll become active during the next identified maintenance period. Learn more about monitoring your data warehouse during an active maintenance event.
Identifying the primary and secondary windows
The primary and secondary windows must have separate day ranges. An example is a primary window of Tuesday–Thursday and a secondary of window of Saturday–Sunday.
To change the maintenance schedule for your data warehouse, complete the following steps:
Sign in to the Azure portal.
Select the data warehouse that you want to update. The page opens on the overview blade.
Open the page for maintenance schedule settings by selecting the Maintenance Schedule (preview) summary link on the overview blade. Or, select the Maintenance Schedule option on the left-side resource menu.
Identify the preferred day range for your primary maintenance window by using the options at the top of the page. This selection determines if your primary window will occur on a weekday or over the weekend. Your selection will update the drop-down values. During preview, some regions might not yet support the full set of available Day options.
Choose your preferred primary and secondary maintenance windows by using the drop-down list boxes:
- Day: Preferred day to perform maintenance during the selected window.
- Start time: Preferred start time for the maintenance window.
- Time window: Preferred duration of your time window.
The Schedule summary area at the bottom of the blade is updated based on the values that you selected.
Select Save. A message appears, confirming that your new schedule is now active.
If you're saving a schedule in a region that doesn't support maintenance scheduling, the following message appears. Your settings are saved and become active when the feature becomes available in your selected region.