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Serverless Architecture

category: Architecture
tags: serverless, faas, cloud, kubernetes, java

Main Topic 1

Serverless Architecture delegates infrastructure management to the cloud, allowing you to write functions that execute on demand without managing servers.

Subtopic A: What It Is

• Functions as a Service (FaaS) – Deploy functions, not services
• Auto-scaling and pay-per-use
• Typically stateless and event-triggered

Subtopic B: Why Use It

• Operational simplicity
• Cost efficiency – Pay only for time used
• Rapid prototyping

Subtopic C: When To Use It

• Lightweight tasks (e.g., webhooks, image processing)
• Event-driven pipelines
• Unpredictable or bursty traffic

Main Topic 2

Code Example (Java Function)

public class HelloHandler implements RequestHandler<Map<String, String>, String> {
    public String handleRequest(Map<String, String> input, Context context) {
        return "Hello, " + input.get("name");
    }
}

Infra Example (Knative on Kubernetes)

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: hello-service
spec:
  template:
    spec:
      containers:
      - image: myregistry/hello-fn:latest

Key Concepts Summary

• Function-based execution
• Scales to zero
• Stateless and reactive design

Best Practices / Tips

1. Keep functions lightweight and fast
2. Use managed secrets and env vars for config
3. Externalize state (e.g., use cloud storage or DB)

Common Issues / Troubleshooting

Problem 1: Cold start latency

• Cause: Function container spin-up delay
• Solution: Use provisioned concurrency if supported

Problem 2: Tight vendor lock-in

• Cause: Proprietary cloud interfaces
• Solution: Use open standards like Knative

References / Further Reading

• https://martinfowler.com/articles/serverless.html
• https://knative.dev/docs/

Last updated: 2025-08-26 20:00 UTC