This diagram shows an architecture topology that includes a primary site, a high availability (HA) site, and a disaster recovery (DR) site. There are two AWS regions (US West and US East) and two OCI regions (OCI Region 1 and OCI Region 2). The AWS US West and OCI 1 regions comprise the primary and HA sites. The AWS US East and OCI 2 regions comprise the DR site.

The infrastructure and components for each site are identical. Each site includes an availability zone (AZ) that contains a virtual private cloud (VPC) to handle user traffic and applications, a transit VPC for connectivity within and between sites, and the ODB network to house Oracle Database@AWS.

External, internet user traffic is routed through an internet gateway and network address translation (NAT) gateways in each VPC. Amazon Route 53 directs traffic to an external load balancer that directs traffic to the application subnet for appropriate site. Internal user traffic is routed to an internal load balancer that directs traffic to the application subnet for the appropriate site.

Each site has a Transit VPC that provides connectivity between the AWS application VPC and the VM cluster in the OCI virtual cloud network (VCN). A transit gateway connects VPCs within a region and across AWS regions to provide transit gateway peering.

ODB network includes an Oracle Database@AWS child site with a single VCN that spans the AWS and OCI regions. The VCN has two subnets: a client subnet that includes a virtual machine (VM) cluster, and a backup subnet that includes an Oracle Exadata Database Service instance. ODB peering connects the transit VPC to the ODB network.