Regional Edge Cache

💡 Definition

Regional Edge Caches are part of the AWS Global Infrastructure used by CloudFront. They sit between your origin server and the global Edge Locations. They have larger cache storage than individual Edge Locations.

🔑 Key Concepts

• Intermediate Cache: Data is retrieved from the origin and cached in the Regional Edge Cache.
• Larger Cache Width: Because they have more storage, they can hold objects for longer periods than Edge Locations.
• Performance: Helps keep data closer to the viewer even if it's not popular enough to stay in the Edge Location cache, reducing the need to go back to the origin server.

⚙️ How it Works

1. User requests content.
2. Request goes to nearest Edge Location.
3. If miss (not in Edge Location), request goes to Regional Edge Cache.
4. If miss (not in Regional Edge Cache), request goes to Origin.
5. Content is cached in Regional Edge Cache, then Edge Location, then sent to user.

🎯 Use Cases

• Content Delivery: Improving cache hit ratios for CloudFront.
• Reducing Origin Load: Protecting your backend infrastructure from traffic spikes.

💰 Pricing Model

• No additional charge for using Regional Edge Caches; it's part of the standard CloudFront pricing.

📝 Exam Tips (CLF-C02)

• They sit between the Origin and the Edge Location.
• They have a larger cache than Edge Locations.
• The goal is to prevent requests from having to go all the way back to the Origin server.

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See Also: * Edge Location * CloudFront