AWS SAA Quick Reference Cheat Sheet

🎯 Core Services Summary

Compute Services

EC2:
  Instance Types: T (burstable), M (general), C (compute), R (memory), X (high memory)
  Pricing: On-Demand > RI (75% off) > Spot (90% off)
  Placement Groups: Cluster (performance), Partition (big data), Spread (HA)

Lambda:
  Timeout: 15 minutes max
  Memory: 128MB - 10,240MB
  Languages: Node.js, Python, Java, C#, Go, Ruby, PowerShell

ECS/EKS:
  ECS: AWS managed containers
  EKS: Kubernetes managed service
  Fargate: Serverless containers

Storage Services

S3:
  Standard: $0.023/GB, immediate access
  Standard-IA: $0.0125/GB, 30-day minimum
  Glacier Instant: $0.004/GB, 90-day minimum
  Glacier Flexible: $0.0036/GB, 90-day minimum
  Deep Archive: $0.00099/GB, 180-day minimum

EBS:
  gp3: 3,000 IOPS baseline, best price/performance
  io2: Up to 64,000 IOPS, high performance
  st1: Throughput optimized HDD
  sc1: Cold HDD, lowest cost

EFS:
  Regional NFS, multiple AZ access
  Performance modes: General Purpose, Max I/O
  Throughput modes: Bursting, Provisioned

Database Services

RDS:
  Engines: MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, Aurora
  Multi-AZ: Synchronous replication, automatic failover
  Read Replicas: Asynchronous, read scaling, cross-region

DynamoDB:
  NoSQL, managed, serverless
  On-Demand: Pay per request
  Provisioned: Pre-configured capacity
  Global Tables: Multi-region replication

Aurora:
  MySQL/PostgreSQL compatible
  6 copies across 3 AZs
  Up to 15 read replicas
  Aurora Serverless: Auto-scaling

Networking Services

VPC:
  Private cloud network
  Subnets: Public (IGW), Private (NAT)
  CIDR: IP address ranges

Load Balancers:
  ALB: Layer 7 (HTTP/HTTPS), content routing
  NLB: Layer 4 (TCP/UDP), ultra-low latency
  CLB: Legacy, basic load balancing

CloudFront:
  Global CDN, 400+ edge locations
  Cache behaviors, TTL settings
  Origin shield, compression

Route 53:
  DNS service, health checks
  Routing: Simple, Weighted, Latency, Failover, Geolocation

🏗️ Architecture Patterns

High Availability

Multi-AZ Deployment:
  Components: ALB, Auto Scaling, RDS Multi-AZ
  Benefits: Fault tolerance, automatic failover

Auto Scaling:
  Target Tracking: CPU, requests per target
  Scheduled: Predictable patterns
  Step: Multiple scaling steps

Performance Optimization

Caching Layers:
  CloudFront: Global edge caching
  ElastiCache: In-memory caching (Redis/Memcached)
  DAX: DynamoDB accelerator

Content Delivery:
  Static content → CloudFront + S3
  Dynamic content → ALB + Auto Scaling
  API responses → API Gateway caching

Security Best Practices

Identity & Access:
  IAM Roles: Temporary credentials
  Least Privilege: Minimum permissions
  MFA: Multi-factor authentication

Data Protection:
  Encryption at Rest: S3, EBS, RDS
  Encryption in Transit: HTTPS, TLS
  Key Management: KMS, CloudHSM

Network Security:
  Security Groups: Instance-level firewall
  NACLs: Subnet-level firewall
  WAF: Web application firewall

Cost Optimization

Compute:
  Reserved Instances: 1-3 year commitment, 75% savings
  Spot Instances: Interruption-tolerant, 90% savings
  Right-sizing: Match capacity to demand

Storage:
  S3 Lifecycle: Automatic class transitions
  Intelligent Tiering: Automatic optimization
  EBS GP3: Better price/performance than GP2

Monitoring:
  Cost Explorer: Analyze spending patterns
  Budgets: Set spending alerts
  Trusted Advisor: Cost recommendations

🔍 Service Limits & Quotas

Important Limits

EC2:
  Default: 20 On-Demand instances per region
  EBS: 5,000 volumes per region
  Security Groups: 2,500 per VPC

S3:
  Bucket Names: Globally unique
  Objects: Unlimited per bucket
  Object Size: 5TB maximum

Lambda:
  Timeout: 15 minutes maximum
  Memory: 10,240MB maximum
  Deployment Package: 50MB zipped, 250MB unzipped

RDS:
  DB Instances: 40 per region
  Read Replicas: 5 per master (Aurora: 15)
  Backup Retention: 35 days maximum

📊 Monitoring & Logging

CloudWatch

Metrics:
  Basic: 5-minute intervals (free)
  Detailed: 1-minute intervals (charged)
  Custom: Application-specific metrics

Alarms:
  Threshold-based monitoring
  Actions: SNS, Auto Scaling, EC2 actions

Logs:
  Centralized logging
  Log groups và streams
  Retention policies

Security Monitoring

CloudTrail:
  API call logging
  S3 delivery
  Multi-region trails

GuardDuty:
  Threat detection
  Machine learning based
  VPC Flow Logs, DNS logs

Security Hub:
  Security posture management
  Compliance standards
  Finding aggregation

🎯 Exam Tips

Key Decision Factors

Performance Requirements:
  Low latency: Choose services closer to users
  High throughput: Horizontal scaling over vertical
  Consistent performance: Provisioned over burstable

Cost Optimization:
  Predictable workloads: Reserved Instances
  Variable workloads: Auto Scaling + Spot
  Storage access patterns: Lifecycle policies

Security Requirements:
  Compliance: KMS, encryption, audit trails
  Network isolation: Private subnets, VPC
  Access control: IAM roles, least privilege

Availability Requirements:
  99.9%: Single AZ with backups
  99.99%: Multi-AZ deployment
  99.999%: Multi-region active/active

Common Question Patterns

"MOST cost-effective":
  Look for: Reserved Instances, Spot, lifecycle policies

"BEST performance":
  Look for: Placement groups, enhanced networking, caching

"Highest security":
  Look for: Private subnets, encryption, IAM roles

"Lowest latency":
  Look for: CloudFront, placement groups, regional services

"Automatic failover":
  Look for: Multi-AZ, Auto Scaling, health checks

🔧 Service Selection Guide

When to Use What

Compute:
  EC2: Full control, custom applications
  Lambda: Event-driven, serverless, < 15 minutes
  ECS: Containerized applications
  Batch: Large-scale batch processing

Storage:
  S3: Object storage, web content, backup
  EBS: Block storage, database storage
  EFS: Shared file system, multiple instances

Database:
  RDS: Relational, ACID compliance
  DynamoDB: NoSQL, high performance, serverless
  Redshift: Data warehouse, analytics
  ElastiCache: Caching, session storage

Networking:
  ALB: HTTP/HTTPS, microservices
  NLB: TCP/UDP, high performance
  CloudFront: Global content delivery
  API Gateway: RESTful APIs, serverless

📚 Study Focus Areas

High Priority Topics

  • [ ] EC2 instance types và pricing models
  • [ ] S3 storage classes và lifecycle
  • [ ] VPC networking và security groups
  • [ ] RDS Multi-AZ vs Read Replicas
  • [ ] Auto Scaling policies
  • [ ] IAM roles và policies
  • [ ] CloudFormation basics

Medium Priority Topics

  • [ ] Lambda functions và triggers
  • [ ] DynamoDB design patterns
  • [ ] CloudFront distributions
  • [ ] ElastiCache configurations
  • [ ] Route 53 routing policies
  • [ ] KMS encryption
  • [ ] CloudWatch monitoring

Lower Priority Topics

  • [ ] Advanced networking (Direct Connect, Transit Gateway)
  • [ ] Specialized services (EMR, Kinesis, Glue)
  • [ ] Container orchestration details
  • [ ] Advanced security services
  • [ ] Cost management tools

🎓 Final Exam Strategy

Time Management

  • [ ] 2 minutes per question average
  • [ ] Mark uncertain questions for review
  • [ ] Answer all questions (no penalty)
  • [ ] Leave 10 minutes for review

Question Analysis

  • [ ] Read question carefully
  • [ ] Identify key requirements
  • [ ] Eliminate obviously wrong answers
  • [ ] Choose BEST option among remaining
  • [ ] Consider AWS Well-Architected principles

Common Mistakes to Avoid

  • [ ] Overcomplicating simple scenarios
  • [ ] Ignoring cost considerations
  • [ ] Missing security requirements
  • [ ] Confusing similar services
  • [ ] Not considering scalability

Good luck với AWS SAA certification! 🌟