CloudFront Part Duex

Content Delivery Overview

CloudFront enhances content delivery performance through edge location caching, supporting both static and dynamic content delivery methods.

Content Types and Delivery Methods

1. Dynamic Content

   • Leverages HTTP cookies forwarded from origin sites

   • Enables personalized content delivery

   • Maintains user context and preferences

2. Media Streaming Capabilities

   • Supports Adobe Flash Media Server's RTMP protocol (requires specific RTMP delivery method)

   • Web distributions (HTTP/HTTPS) support:

     • Media streaming

     • Live streaming

     • Standard content delivery

Origin Configuration

Supported Origin Types

• Amazon S3 buckets

• EC2 instances

• Elastic Load Balancers

• External web servers

• Multiple origins within single distribution

URL Path-Based Behaviors

Example WordPress Configuration:

• Route 53 → CloudFront Distribution

• Static content → S3 bucket

• Dynamic content → Load balancer with EC2 fleet

Cache Management

Cache Invalidation Methods

When you need to remove content from CloudFront's edge caches before it expires, you have several options for cache invalidation:

1. Version or Path Management

   • Instead of invalidating objects, create a new path for updated content (recommended approach)

   • Use object versioning in the URL (e.g., /images/product-v2.jpg)

   • Most cost-effective and efficient method as it avoids invalidation fees

2. Origin File Management

   • Removing files from the origin alone doesn't invalidate the CloudFront cache

   • Objects remain in edge caches until their TTL expires

   • TTL values are defined in cache behaviors at the distribution level

   • Can be configured using Cache-Control and Expires headers

3. CloudFront Console Options

   • Create invalidations for specific paths using wildcards (e.g., /images/*)

   • Perform full distribution invalidation (not recommended for production)

   • Monitor invalidation status and history

   • First 1,000 paths invalidated per month are free

4. Programmatic Invalidation

   • Use AWS SDK or AWS CLI to automate invalidations

   • Integrate with deployment pipelines using CreateInvalidation API

   • Monitor invalidation progress using GetInvalidation API

   • Implement rate limiting to avoid API throttling

Key Considerations:

• Invalidations propagate to all edge locations, which can take several minutes

• Each invalidation path counts toward your monthly quota

• Using versioning or path-based updates is more efficient than invalidation

• Wildcards (*) count as one path but can match multiple objects

DNS and Domain Configuration

Zone Apex Support

• Allows bare domain usage (without www)

• Example: domain.com instead of www.domain.com

• Direct DNS resolution to CloudFront distribution

Geographic Access Control

Geo-Restriction Features

• Whitelist: Explicitly allow specific countries

• Blacklist: Explicitly block specific countries

Use Cases

• Regulatory compliance

• Content licensing restrictions

• Regional access management

• Geographic content distribution control

Best Practices

1. Content Organization

   • Structure content paths logically

   • Utilize path-based behaviors effectively

   • Separate static and dynamic content

2. Cache Strategy

   • Configure appropriate TTL values

   • Plan invalidation strategy

   • Monitor cache hit ratios

3. Security

   • Implement appropriate geo-restrictions

   • Configure HTTPS when needed

   • Manage origin access properly

4. Performance Optimization

   • Use multiple origins strategically

   • Configure behaviors based on content type

   • Monitor and adjust based on usage patterns