Maintenance tasks on Azure SQL Managed instance

Question

I have 4 SQL managed instances and have some custom task defined on SQL Managment Studio. On azure I found that the managed instance have a Maintenance Window:

My question is.. What kind of tasks are performed in the Azure maintenance window?

I only found this about azure maintenance window https://learn.microsoft.com/en-us/azure/azure-sql/database/maintenance-window?view=azuresql, but i want to know list of operations that azure does during this maintenance...

Thanks!

Answer 1

The maintenance window feature provides you with the ability to onboard Azure SQL resource to prescheduled time blocks outside of business hours.

As per this Official Microsoft documentation

These are types of the updates performed during a maintenance window.

• Hardware
  
• Firmware
  
• Operating system
  
• Satellite software components
  
• SQL Engine
  

They're typically combined into a single batch to minimize the incidence of maintenance events.

These are some of the approaches and operations involved in the maintenance window:

• Hot patching or dynamic patching to apply updates without restarting the services.
  
• Maintaining a quorum of database replicas for the high-availability of Azure database infrastructure.
• Uses Automatic Scheduling to prevent updates during region’s peak business hours.
• Analysing database workload patterns to chose the best time for failover resources.

SOURCES:
https://www.sqlshack.com/azure-sql-database-maintenance-window/ by Rajendra Gupta.

Maintenance Window FAQ - Azure SQL | Microsoft Docs