AlwaysOn Availability Group Concepts and Terminology
An AlwaysOn availability group is a group of databases that can fail over from a primary server to a secondary server automatically or manually, as and when required. Commonly known as AlwaysOn AGs, they're the premium high availability and disaster recovery solution available in SQL Server.
Other than being an HA and a DR solution, it can also be used to load-balance read workloads, for maintenance jobs such as backups, and for consistency checks on the secondary databases.
Availability Groups Concepts and Components
A typical AlwaysOn AG topology is shown in the following diagram:
Figure 4.1: Example of an AlwaysOn topology
The given AlwaysOn implementation consists of three replicas or nodes: Primary Replica, Secondary Replica 1, and Secondary Replica 2. The three nodes are part of the same domain name and the same Windows Server Failover Cluster.
An AlwaysOn AG consists of the following components.
Windows Server Failover Cluster
A Windows...
