Even when your databases are hosted in Azure, there is still a chance that failures and outages will occur. In the case of an outage (such as a total regional failure, which can be caused by a natural disaster, an act of terrorism, war, a government action, or a network or device failure external to the data centers of Microsoft), your data still needs to be accessible.

To create highly available SQL Server databases on Azure, you can use failover groups and active geo-replication, described in the following list:

• Active geo-replication: Geo-replication is a business continuity feature that allows you to replicate the primary database and up to four read-only secondary databases, in the same or different Azure regions. You can use the secondary databases to query data, or for failover scenarios when there is a data center outage. Active geo-replication has to be set up by the user or the application manually.
• Failover groups: Failover groups are a feature that automatically manages the failover for the database. They automatically manage the geo-replication relationship between the databases, the failover at scale, and the connectivity. To use failover groups, the primary and the secondary databases need to be created inside of the same Azure subscription.

In the next section, we are going to cover how to provision and configure an Azure SQL database.