Always On Availability Groups
Always On Availability Groups is a high availability and disaster recovery feature that was introduced in SQL Server 2012. This feature, similar to Always On Failover Cluster Instance, requires WSFC to be configured on the nodes running on SQL Server. Availability Groups (AGs) work at a database level, where the FCI protects the whole instance.
We won't focus on WSFC anymore and will just use the common platform to deploy the SQL Server Always On Availability Groups in the following scenarios in the chapter. The WSFC configuration for AGs is simpler when compared to the FCI infrastructure since AGs don't require any shared storage and the storage solution depends on the node type. To utilize AGs, install the standalone SQL Server on the cluster nodes, but use the basic SQL Server installation, since the instances in AGs don't share the SQL Server VNN and IP, and are independent of each other.
