OCI Application Deployment

✅ Completed: 2-Tier Architecture

We successfully created a 2-Tier application where the App VM inserts and reads data from Oracle Autonomous DB securely over OCI networking.

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🚀 Next Step: 3-Tier Architecture

We need to create a 3-Tier application with three subnets (Web, App & DB).

• The application in the App Instance (App Subnet) is accessible through a Load Balancer in the Web Subnet.
• The App is able to insert and read data from Oracle Autonomous DB (DB Subnet) securely over OCI networking.

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🔹 Planned Setup

VCN

• Spoke_VCN: 10.1.0.0/16

Subnets

• Spoke_Web_Subnet (10.1.1.0/24) → Internet Gateway attached
• Spoke_App_Subnet (10.1.2.0/24)
• Spoke_DB_Subnet (10.1.3.0/24)

Each subnet will have its own custom Security List and Route Table.

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🔹 Components

• Autonomous Database → Created earlier as part of 2-Tier Architecture
• Bastion Server → In Web Subnet (from custom image, wallet configured in /var/www/html)
• App Server → In App Subnet (from the same custom image)
• Load Balancer → In Web Subnet

All 3 Subnets have dedicated Security List rules

Login to Bastion server and then SSH to the Application Server. Run the App.py script in /var/www/html

✅ Summary

We created a 3‑Tier application where the App VM inserts and reads data from Oracle Autonomous DB securely over OCI networking.