Deploying Spring Boot Applications on AWS: ECS vs. Lambda

Deploying a Spring Boot application on AWS requires choosing the right compute service that balances scalability, performance, and cost-efficiency. Two popular AWS options for running Spring Boot applications are AWS Elastic Container Service (ECS) and AWS Lambda. This guide explores their differences, best use cases, and how to deploy a Spring Boot application on both.

1. Understanding ECS and Lambda

AWS Elastic Container Service (ECS)

AWS ECS is a container orchestration service that allows you to deploy, manage, and scale containerized applications using Docker.

• Supports custom environments with control over the OS, dependencies, and configurations.
• Can run on EC2 (self-managed infrastructure) or Fargate (serverless compute).
• Ideal for long-running applications and microservices architectures.

Example Use Case: Deploying a Spring Boot REST API as a Docker container that handles high-traffic workloads.

AWS Lambda (Serverless Compute)

AWS Lambda allows running code without provisioning or managing servers. It executes code only when triggered and scales automatically.

• No infrastructure management, runs fully serverless.
• Auto-scales based on incoming requests.
• Best suited for event-driven applications with short-lived execution.

Example Use Case: A Spring Boot API that performs lightweight tasks such as processing form submissions or triggering database updates.

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2. Key Differences Between ECS and Lambda

Feature	AWS ECS	AWS Lambda
Compute Model	Container-based	Serverless, function-based
Scalability	Auto-scales with ECS Service Auto Scaling	Auto-scales per request
Pricing Model	Pay for instance/container usage	Pay per execution time
Startup Time	Always running or cold starts in Fargate	Cold starts (~100ms) for inactive functions
Use Case	Long-running apps, microservices	Event-driven tasks, API backends

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3. Deploying a Spring Boot Application on AWS ECS

Step 1: Containerizing the Spring Boot App

# Dockerfile
FROM openjdk:17-jdk-slim
VOLUME /tmp
COPY target/myapp.jar app.jar
ENTRYPOINT ["java", "-jar", "app.jar"]

Step 2: Push the Image to Amazon Elastic Container Registry (ECR)

aws ecr create-repository --repository-name spring-boot-app
aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin <your-ecr-url>
docker build -t spring-boot-app .
docker tag spring-boot-app:latest <your-ecr-url>/spring-boot-app:latest
docker push <your-ecr-url>/spring-boot-app:latest

Step 3: Deploying the Container on ECS (Fargate Mode)

aws ecs create-cluster --cluster-name springboot-cluster
aws ecs create-task-definition --family springboot-task \
  --network-mode awsvpc --requires-compatibilities FARGATE \
  --cpu 512 --memory 1024 --container-definitions '[{"name":"spring-boot-container","image":"<your-ecr-url>/spring-boot-app:latest","portMappings":[{"containerPort":8080,"hostPort":8080}]}]'

Step 4: Running the Service

aws ecs create-service --cluster springboot-cluster --service-name springboot-service \
  --task-definition springboot-task --desired-count 1 --launch-type FARGATE \
  --network-configuration 'awsvpcConfiguration={subnets=[subnet-abc123],securityGroups=[sg-xyz123],assignPublicIp="ENABLED"}'

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4. Deploying a Spring Boot Application on AWS Lambda

Step 1: Convert Spring Boot to a Serverless Function

Use AWS Lambda Adapter or Spring Cloud Function to run Spring Boot as a function.

@SpringBootApplication
public class LambdaApplication implements RequestHandler<Map<String, Object>, String> {
    @Override
    public String handleRequest(Map<String, Object> input, Context context) {
        return "Hello from AWS Lambda!";
    }
}

Step 2: Build and Package the Application

mvn clean package
zip -j target/lambda.zip target/myapp.jar

Step 3: Deploy to AWS Lambda

aws lambda create-function --function-name SpringBootLambda \
  --runtime java17 --role <iam-role-arn> \
  --handler LambdaApplication::handleRequest --zip-file fileb://target/lambda.zip

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5. Choosing Between ECS and Lambda for Spring Boot

Use ECS When:

• The application requires long-running processes.
• You need full control over networking, dependencies, and configuration.
• The application handles high traffic and needs persistent connections.
• You require integration with databases like RDS or DynamoDB.

Use Lambda When:

• The application is event-driven (e.g., API Gateway, S3, DynamoDB events).
• You need auto-scaling without server management.
• The application has low execution time and doesn’t require persistent state.
• You are optimizing for cost efficiency with a pay-per-execution model.

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Conclusion

AWS ECS and Lambda offer different deployment strategies for Spring Boot applications. ECS is ideal for long-running, scalable applications, while Lambda is best suited for lightweight, event-driven workloads. Choosing the right solution depends on the application’s requirements, scalability needs, and cost considerations.

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