This image shows an Oracle Cloud Region with a VCN and an availability domain with two fault domains. There are 2 public subnets and two private subnets. Each subnet has a route table and a security list.
The first public subnet contains a bastion host in fault domain 2. The second public subnet contains an active load balancer in fault domain 1 and a standby load balancer in fault domain 2. The load balancers are connected to each other and to the Internet Gateway. The load balancers are also connected to Apache Tomcat servers in the first private subnet (a Tomcat server is in each fault domain). The second private subnet contains an autonomous database that's connected to the Tomcat server in fault domain 1 and the Tomcat server in fault domain 2. Data flows between the autonomous database and each Tomcat server, and between the database and the bastion host. Data flows between each Tomcat server and the bastion host. The diagram components are described in the surrounding text.