Designing and Implementing a High-Availability Infrastructure for a Web Application on AWS

by Dorila RAKIPLLARI

Abstract
The design and implementation of a high-availability infrastructure for a three-tier web application on Amazon Web Services (AWS) addresses the increasing demand for resilient, scalable, and cost-effective cloud solutions. In many cases, organizations relying on traditional monolithic or single-instance deployments face frequent failures, limited fault tolerance, and difficulties in handling traffic surges. Such limitations create risks of downtime and service disruption, reducing customer satisfaction and increasing operational costs.
To overcome these challenges, a methodology grounded in cloud architecture principles and Infrastructure as Code (IaC) practices was applied. Terraform was employed to automate infrastructure provisioning and ensure consistency across environments. The solution integrates fundamental AWS services including Virtual Private Cloud (VPC) for networking, Application Load Balancers for distributing traffic, Auto Scaling Groups for dynamic resource allocation, and Amazon RDS for database reliability. The infrastructure was deployed across multiple Availability Zones to guarantee redundancy and tested under varying workloads to validate its ability to adapt to demand. The analysis confirms that the proposed architecture enhances resilience, minimizes single points of failure, and enables automated recovery from instance-level disruptions. In addition, it demonstrates cost optimization through on-demand scaling and reduced administrative overhead due to automation. The implications are relevant for both academic and professional audiences, highlighting the practical value of high-availability designs on AWS as a pathway toward secure, sustainable, and efficient digital services.

Keywords: AWS; High Availability; Cloud Infrastructure; Auto Scaling; Load Balancer; Terraform