This image shows an Oracle Cloud Infrastructure region that provides object storage (for backup) for the region. The region includes a single availability domain with three fault domains. The availability domain includes block storage (for volumes) for the domain. It also includes a virtual cloud network (VCN) with four regional subnets and a service gateway. The VCN provides routing tables for each subnet and each subnet provides its own security list access. The regional subnets are arranged as functional layers:

• Bastion host layer (regional public subnet): A Bastion host resides in each of the fault domains and together they manage traffic to the Quorum and Microsoft SQL Server database layers. An internet gateway provides a public connection.

• Quorum server layer (regional private subnet): A single Quorum witness server resides in fault domain 1 to manage synchonization and replication to ensure that there is only one owner of a particular resource group at any given time.

• Microsoft SQL Server Always On availability group (regional private subnet): A Primary Microsoft SQL server resides in fault domain 1 and communicates with secondary Microsoft SQL servers in fault domains 2 and 3.

• Domain controller layer (regional private subnet): A domain controller resides in each of the three fault domains.