Service Guide

Features & Use Cases

Load Balancer Comparison

Feature ALB NLB GWLB
OSI Layer Layer 7 (HTTP/HTTPS) Layer 4 (TCP/UDP) Layer 3 (IP)
Routing Path, Host, Header Flow Hash Flow Hash
Performance High Ultra High High
Use Case Web Applications Gaming, IoT Firewalls, IDS

Scaling Strategies

Reactive Scaling

Scale based on current metrics

Predictive Scaling

ML-based future demand prediction

Scheduled Scaling

Time-based scaling actions

Manual Scaling

On-demand capacity changes

Best Practices

Design for Failure

Assume components will fail

Loose Coupling

Minimize dependencies between components

Stateless Design

Store state externally

Monitor Everything

Comprehensive monitoring and alerting

Common Use Cases

Web Applications

Scalable web tier with ALB

  • • ALB for HTTP/HTTPS traffic
  • • Auto Scaling for web servers
  • • RDS Multi-AZ for database

Gaming Applications

Low latency with NLB

  • • NLB for TCP/UDP traffic
  • • Static IP addresses
  • • Ultra-low latency

Microservices

Container-based architecture

  • • ECS/EKS with ALB
  • • Service discovery
  • • Auto Scaling services

Service Guide Exam Tips

  • • Choose ALB for HTTP/HTTPS with advanced routing, NLB for TCP/UDP with ultra-high performance
  • • Target tracking scaling is the recommended approach for most Auto Scaling scenarios
  • • Always design stateless applications to enable horizontal scaling
  • • Use multiple AZs for high availability and distribute load evenly
  • • Implement health checks at both ELB and Auto Scaling Group levels
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