Deploy a Spring Boot App on AWS EC2 with Load Balancer (Step-by-Step Guide)

---

🌍 Introduction

Deploying your application manually on AWS can be time-consuming and error-prone. You might face:

• Traffic distributed unevenly across instances ❌
• Manual setup of health checks and failover ❌
• Lack of scalability and high availability ❌

👉 That’s where EC2 + ELB (Elastic Load Balancer) deployment shines.

By the end, you’ll understand how to deploy a Spring Boot app on multiple EC2 instances, set up an Application Load Balancer, and route traffic intelligently.

👉 Flow: Browser → ELB → EC2 Instances running Spring Boot

---

🔒 Step 1: Prepare Your Spring Boot App

Before we touch AWS, package your Spring Boot project into a runnable .jar file:

mvn clean package

You’ll get something like app.jar in the target/ directory.

✅ We assume the app runs on port 8080 ✅ Requires Java and Maven installed locally ✅ Target is .jar deployment, not Docker

---

⚡ Step 2: Launch EC2 Instances

Let’s spin up two EC2 instances for our Spring Boot app:

1. Go to AWS Console → EC2 → Launch Instance
2. OS: Ubuntu Server 24.04 LTS (Free Tier eligible)
3. Instance type: t2.micro
4. Key Pair: Create/choose one (for SSH access)

5. Configure Security Group:

   • SSH (22) → Your IP
   • HTTP (80) → Anywhere
   • Custom TCP (8080) → Anywhere (for Spring Boot)

🎯 Launch two EC2 instances with the same configuration.

---

📜 Step 3: Install Java & Deploy Spring Boot App

SSH into both instances:

ssh -i your-key.pem ubuntu@<EC2_PUBLIC_IP>

Install Java:

sudo apt update
sudo apt install openjdk-21-jdk -y

Upload your app using scp:

scp -i your-key.pem app.jar ubuntu@<EC2_PUBLIC_IP>:/home/ubuntu/

Run the app in the background:

sudo nohup java -jar app.jar > app.log 2>&1 &

Breakdown:

• nohup: Keeps process running after logout
• java -jar: Runs your Spring Boot app
• > app.log 2>&1 &: Logs output and runs in background

✅ Now access your app via:

http://<EC2_PUBLIC_IP>:8080/api/adapt/welcome

Repeat for the second EC2 instance.

---

🌐 Step 4: Create an Elastic Load Balancer (ALB)

Now we’ll route traffic to both EC2 instances via a Load Balancer.

1. Go to EC2 → Load Balancers
2. Click Create Load Balancer → Application Load Balancer
3. Name: springboot-alb
4. Scheme: Internet-facing
5. VPC: Use default VPC
6. Select AZs: Pick where your EC2s are running

7. Security Group:

   • Create a new one: springboot-sg
   • Inbound Rules: Allow HTTP (80) and SSH (22)

Listener Setup

• Protocol: HTTP
• Port: 80

Create Target Group

• Type: Instances
• Name: springboot-tg
• Protocol: HTTP
• Port: 8080
• Health check path: /actuator/health/readiness

✅ Register your two EC2 instances ✅ Attach this Target Group to the Load Balancer ✅ Click Create Load Balancer

Your ALB is now live and routing traffic.

---

🧪 Step 5: Test Your Setup

🎯 Go to Load Balancer → Description tab 📄 Copy the DNS name (e.g., springboot-alb-123456.ap-south-1.elb.amazonaws.com)

Visit:

http://<DNS_NAME>/api/adapt/welcome

Expected Output:

Welcome to Adaptation Controller - Techeazy

✅ Confirms ELB is routing to healthy EC2 instances ✅ Confirms Spring Boot app is working across both instances

🛠 You can now explore:

• Manual deployment
• Creating AMIs
• Using Launch Templates with Auto Scaling

---

🎯 Conclusion

You’ve successfully:

✅ Deployed a Spring Boot app on EC2 ✅ Set up a Load Balancer to route traffic ✅ Configured health checks to ensure uptime ✅ Created a production-ready architecture for web-scale apps

👉 Next, pair this setup with Auto Scaling Groups for true elasticity and high availability.

---

✅ Next Steps

🚀 Be interview-ready in the era of AI & Cloud — start your DevOps journey today! 💡 YouTube won’t get you a job. Real projects + real internship certificate will. 🔥 AI is reshaping jobs. Don’t watch it happen, be part of it with DevOps & Cloud skills. 🎯 ₹2000/month today = Dream job tomorrow. Secure your spot now. ⏳ Every month you wait, Cloud + AI jobs are being filled. Don’t miss out! 🌐 DevOps + AWS + AI = The skillset every recruiter is hunting for in 2025.

👉 Register now at TechEazy Consulting

---