AWS Cloud watch Auto scaling alarm [PROJECT - 4]

This project implements an automated scaling solution using AWS CloudWatch Alarms to dynamically adjust EC2 instances based on real-time metrics (e.g., CPU utilization, memory, or network traffic). By setting up threshold-triggered alarms, the system scales resources up/down via Auto Scaling Groups (ASG), ensuring cost-efficiency and high availability. The solution enhances performance during demand spikes while reducing costs during low-traffic periods.

3/26/20253 min read

Project Title: AWS Auto Scaling with CloudWatch Alarms, VPC, ALB, and Secure Subnet Architecture

Project Overview

Designed and deployed a highly available, auto-scaling AWS infrastructure leveraging CloudWatch Alarms, Application Load Balancer (ALB), and a secure VPC architecture with public and private subnets. The system dynamically scales EC2 instances based on real-time performance metrics (CPU, memory, network) while maintaining security best practices by isolating backend instances in private subnets.

Key Components & Implementation

VPC & Network Architecture
- Created a custom VPC with public and private subnets across multiple Availability Zones (AZs) for fault tolerance.
- Public Subnets: Hosted Internet-facing resources (ALB, NAT Gateway).
- Private Subnets: Secured backend EC2 instances (no direct internet access).
- Configured Route Tables, Internet Gateway (IGW), and NAT Gateway for controlled traffic flow.
Application Load Balancer (ALB) in Public Subnet
- Deployed an ALB in public subnets to distribute traffic across auto-scaled EC2 instances.
- Configured Target Groups for health checks and routing.
- Enabled HTTPS (SSL/TLS) for secure communication (optional).
Auto Scaling Group (ASG) with CloudWatch Alarms
- Set up Launch Templates to define EC2 configurations (AMI, instance type, user data).
- Created Auto Scaling Policies for:
  - Scale-Out: Triggered when CPU > 70% (add instances).
  - Scale-In: Triggered when CPU < 30% (remove instances).
- Integrated CloudWatch Alarms to monitor metrics and trigger scaling events.
Security & IAM Policies
- Applied IAM Roles & Policies to grant least-privilege permissions to EC2 instances (e.g., CloudWatch access).
- Used Security Groups to restrict traffic:
  - ALB (HTTP/HTTPS from the internet).
  - EC2 Instances (only allow traffic from ALB).
High Availability & Fault Tolerance
- Distributed instances across multiple AZs for resilience.
- Ensured self-healing—failed instances are automatically replaced.

Why This Project?

Optimized Cost & Performance: Auto-scaling reduces costs during low traffic while handling spikes efficiently.
Secure Architecture: Backend instances in private subnets are protected from direct exposure.
Real-World Applicability: Mimics production-grade AWS setups used in scalable web apps.

Technologies Used

AWS Services: EC2, VPC, ALB, CloudWatch, Auto Scaling, IAM, NAT Gateway, Route 53.
Concepts: High Availability, Fault Tolerance, Horizontal Scaling, Infrastructure as Code.