Solution Architecture Journey: Scaling a Simple Web Application

Introduction

In this architecture discussion, we explore how a simple web application, WhatIsTheTime.com, evolves from a basic single-instance setup to a highly available, scalable, and cost-optimized cloud architecture using AWS EC2, Elastic Load Balancing (ELB), Route 53, and Auto Scaling Groups (ASG).

Phase 1: Basic Setup

1. Initial Proof of Concept (PoC)

• The simplest version of the app consists of:
  • A T2 Micro EC2 instance with a public IP.
  • A user requests the time, and the server responds.
  • To maintain a static IP, we attach an Elastic IP.

🟢 Pros: Simple and functional.

🔴 Cons: Limited capacity, potential downtime if the instance stops.

Phase 2: Vertical Scaling

2. Upgrading to a Larger Instance

• Due to increasing traffic, the T2 Micro is insufficient.
• The instance is upgraded to an M5 Large instance.
• Downtime occurs during the upgrade process.

🟢 Pros: More powerful instance, better performance.

🔴 Cons: Downtime during upgrade, limited by the largest instance available.

Phase 3: Horizontal Scaling

3. Adding Multiple EC2 Instances