Always On Platinum v4

The Always On Platinum architecture includes the following:

• Four BDR data nodes (two in location A, two in location B)
• Two logical standby nodes (one in location A, one in location B)
• One witness node in location C (optional but recommended)
• Four HARP-Proxy nodes (two in location A, two in location B)
• Two Barman nodes (one in location A, one in location B)

Both locations have redundant hot standby hardware to maintain local high availability in case of a hardware failure without waiting to restore a BDR node from backup.