Scenario: In the event of an Azure regional outage, ensure that the customers can access the PaaS solution with minimal downtime. The solution must provide automatic failover.
The auto-failover groups feature allows you to manage the replication and failover of a group of databases on a server or all databases in a managed instance to another region. It is a declarative abstraction on top of the existing active geo-replication feature, designed to simplify deployment and management of geo-replicated databases at scale. You can initiate failover manually or you can delegate it to the Azure service based on a user-defined policy.
The latter option allows you to automatically recover multiple related databases in a secondary region after a catastrophic failure or other unplanned event that results in full or partial loss of the SQL Database or SQL Managed Instance availability in the primary region.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/auto-failover-group-overview
Topic 1, Contoso Ltd
Existing Environment
Contoso, Ltd. is a financial data company that has 100 employees. The company delivers financial data to customers.
Active Directory
Contoso has a hybrid Azure Active Directory (Azure AD) deployment that syncs to on-premises Active Directory.
Database Environment
Contoso has SQL Server 2017 on Azure virtual machines shown in the following table.

SQL1 and SQL2 are in an Always On availability group and are actively queried. SQL3 runs jobs, provides historical data, and handles the delivery of data to customers.
The on-premises datacenter contains a PostgreSQL server that has a 50-TB database.
Current Business Model
Contoso uses Microsoft SQL Server Integration Services (SSIS) to create flat files for customers. The customers receive the files by using FTP.
Requirements
Planned Changes
Contoso plans to move to a model in which they deliver data to customer databases that run as platform as a service (PaaS) offerings. When a customer establishes a service agreement with Contoso, a separate resource group that contains an Azure SQL database will be provisioned for the customer. The database will have a complete copy of the financial data. The data to which each customer will have access will depend on the service agreement tier. The customers can change tiers by changing their service agreement.
The estimated size of each PaaS database is 1 TB.
Contoso plans to implement the following changes:
Business Goals
Contoso identifies the following business requirements:
Technical Requirements
Contoso identifies the following technical requirements:
Monitoring Requirements
Contoso identifies the following monitoring requirements:
PaaS Prototype
During prototyping of the PaaS solution in Azure, you record the compute utilization of a customer's Azure SQL database as shown in the following exhibit.

Role Assignments
For each customer's Azure SQL Database server, you plan to assign the roles shown in the following exhibit.