AWS 3-Tier Setup: NGINX, Tomcat, MySQL

Welcome to Day 29 of my #90DaysOfCloud journey!
Today, we built a Three-Tier Web Application architecture on AWS using:

🌐 NGINX as a reverse proxy
🧠 Java Web App deployed on Apache Tomcat
🗄️ MySQL on Amazon RDS as the database layer

This setup demonstrates a scalable and secure architecture that separates the presentation, application, and data layers.

🧱 Architecture Overview

         Internet (Browser)
               │
        ┌────────────┐
        │   NGINX    │  ← Public Subnet (EC2)
        └─────┬──────┘
              │
        ┌─────▼──────┐
        │  Tomcat    │  ← Private Subnet (EC2)
        └─────┬──────┘
              │
        ┌─────▼──────┐
        │  RDS MySQL │  ← Private Subnet (RDS)
        └────────────┘

🎯 Objective

Deploy a Java-based registration app in a 3-tier architecture using:

A reverse proxy (NGINX) in public subnet
A Tomcat server (EC2) in a private subnet
A MySQL database hosted on AWS RDS

🛠️ Step-by-Step Implementation

This tutorial will walk you through deploying a classic three-tier application (Nginx + Tomcat + MySQL RDS) on AWS. Each step lists all the required commands, configuration details, and helpful comments for publishing as an in-depth Hashnode blog.

1. Launch AWS EC2 Instances

Create two EC2 instances:
- Nginx Server
- Tomcat Application Server
Open the following ports in your EC2 security groups:
- Nginx: 80 (HTTP), 22 (SSH)
- Tomcat: 8080 (Tomcat), 22 (SSH)
Ensure both instances are in the same VPC/subnet for internal communication.

2. Set Up Nginx as a Reverse Proxy

On the Nginx EC2 instance:

# Update the system
sudo yum update -y

# Install Nginx
sudo yum install nginx -y

# Enable and start Nginx
sudo systemctl enable nginx
sudo systemctl start nginx

# Check Nginx status
sudo systemctl status nginx

Configure Nginx to Proxy to Tomcat:

Find your Tomcat server's private IP. Edit the Nginx config:

sudo vim /etc/nginx/nginx.conf

Add this server block above the closing } for the http block:

server {
    listen 80;
    location / {
        proxy_pass http://<Private-IP-of-Tomcat-Server>:8080/student/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Replace <Private-IP-of-Tomcat-Server> with your Tomcat instance's private IP.

Reload Nginx:

sudo nginx -t   # Confirm no syntax errors
sudo systemctl reload nginx

3. Set Up Tomcat with Java Application

On the Tomcat EC2 instance:

# Install Java
sudo yum install java-1.8.0-openjdk -y
java -version    # Should print Java version info

# Download and extract Tomcat 9 (latest version link: https://tomcat.apache.org/download-90.cgi)
cd /opt
sudo curl -O https://downloads.apache.org/tomcat/tomcat-9/v9.0.85/bin/apache-tomcat-9.0.85.tar.gz
sudo tar -xvzf apache-tomcat-9.0.85.tar.gz
sudo mv apache-tomcat-9.0.85 tomcat9

# Start Tomcat
cd /opt/tomcat9/bin
sudo ./startup.sh

# (Optional) Check Tomcat running
curl http://localhost:8080

Deploy the Application:

cd /opt/tomcat9/webapps
sudo curl -O https://s3-us-west-2.amazonaws.com/studentapi-cit/student.war

Restart Tomcat if needed:

cd /opt/tomcat9/bin
sudo ./shutdown.sh
sudo ./startup.sh

4. Create an AWS RDS MySQL Database

Go to AWS RDS console.
Launch a new MySQL instance.
- Set DB name: studentapp
- Record your endpoint, username, and password
- Make it accessible to EC2 (adjust VPC security group).

On Tomcat EC2:

# Install MySQL client to connect to RDS
sudo yum install mysql -y

# Connect to RDS (replace placeholders)
mysql -h <rds-endpoint> -u <username> -p

Run these SQL commands:

sql
CREATE DATABASE studentapp;
USE studentapp;
CREATE TABLE IF NOT EXISTS students(
  student_id INT NOT NULL AUTO_INCREMENT,
  student_name VARCHAR(100) NOT NULL,
  student_addr VARCHAR(100) NOT NULL,
  student_age VARCHAR(3) NOT NULL,
  student_qual VARCHAR(20) NOT NULL,
  student_percent VARCHAR(10) NOT NULL,
  student_year_passed VARCHAR(10) NOT NULL,
  PRIMARY KEY (student_id)
);

5. Configure Tomcat to Use MySQL

Download JDBC Driver:

cd /opt/tomcat9/lib
sudo curl -O https://s3-us-west-2.amazonaws.com/studentapi-cit/mysql-connector.jar

Edit Tomcat’s context configuration:

sudo vi /opt/tomcat9/conf/context.xml

Add (inside the <Context> block):

xml
<Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"
    maxTotal="500" maxIdle="30" maxWaitMillis="1000"
    username="admin" password="your_password" driverClassName="com.mysql.cj.jdbc.Driver"
    url="jdbc:mysql://<rds-endpoint>:3306/studentapp?useUnicode=yes&amp;characterEncoding=utf8"/>

Replace admin, your_password, and <rds-endpoint> with your values.

Restart Tomcat:

cd /opt/tomcat9/bin
sudo ./shutdown.sh
sudo ./startup.sh

6. Validate Your Deployment

Open your browser and go to http://<Nginx-EC2-public-IP>/
Fill the student registration form; check if the data is saved to the MySQL RDS DB.

7. Wrap-Up: What You've Achieved

Nginx proxy routes web traffic to Tomcat.
Java app on Tomcat stores data in MySQL RDS.
End-to-end AWS deployment using EC2, RDS, Nginx, Tomcat—with all commands and config steps included.