CDN Dynamic Acceleration – How to Accelerate APIs and Dynamic Content

Overview

cdn is often considered a static resource acceleration tool. For dynamic content such as API requests, user logins, and shopping carts, traditional CDNs have limited effect. But modern CDNs provide "dynamic acceleration" features that can significantly reduce latency through route optimization and protocol optimization without caching.

This article introduces the principles, applicable scenarios, and configuration methods of CDN dynamic acceleration.

I. What Is Dynamic Acceleration?

Dynamic acceleration differs from static acceleration: static acceleration caches content on edge nodes, and users read the cache directly; dynamic acceleration does not cache content but optimizes the transmission path from the user to the origin server, reducing network latency and packet loss.

Core technologies of dynamic acceleration include:

• Intelligent routing: Automatically selects the optimal network path, avoiding congested nodes
• TCP optimization: Uses congestion control algorithms such as BBR to improve transmission efficiency
• Connection reuse: Reuses CDN-to-origin connections, reducing handshake overhead
• Protocol optimization: Supports HTTP/2 and HTTP/3, reducing round-trip latency

II. Applicable Scenarios

Dynamic acceleration is particularly suitable for the following scenarios:

• API services: RESTful APIs and GraphQL interfaces, where response time directly affects user experience
• Login/payment interfaces: Cannot be cached, but require extremely low latency
• Real-time data: Stock prices, weather information, game leaderboards
• Cross-region users: Origin server in the US, users distributed globally

If your users are mainly concentrated in one region (such as mainland China), the benefits of dynamic acceleration may not be obvious. But if users are distributed globally, dynamic acceleration can significantly improve long-distance access experience.

III. Dynamic Acceleration Support of Mainstream CDNs

IV. Configuration Example: Cloudflare Dynamic Acceleration

Cloudflare's free plan already includes basic dynamic acceleration optimization (TCP optimization, protocol optimization). For more advanced intelligent routing (Argo), payment is required.

Cloudflare Free Plan Dynamic Optimization Configuration:

1. Log in to the Cloudflare console and select your domain
2. Go to "Speed" → "Optimization"
3. Enable "Automatic Optimization"
4. Ensure "HTTP/2" and "HTTP/3" are enabled
5. In "Network" settings, ensure "WebSockets" is enabled (if real-time communication is needed)

Argo intelligent routing configuration:

1. Go to "Traffic" → "Argo Smart Routing"
2. Enable "Argo Smart Routing"
3. Cloudflare will automatically select the optimal path to your origin server

Argo can significantly reduce latency for cross-continent access, with clear improvements for API service user experience.

V. Configuration Example: Upyun Dynamic Acceleration

1. Log in to the Upyun console and select your CDN service
2. Go to "Dynamic/Static Acceleration" settings
3. Select "Dynamic Acceleration" mode
4. Configure acceleration region (China/Global)
5. Set cache rules (dynamic paths can be set to 0 cache)

Upyun dynamic acceleration is billed by traffic, with prices slightly higher than static CDN, but for API services, the cost is still manageable.

VI. How to Verify Dynamic Acceleration Effect

Use the following methods to verify whether dynamic acceleration is working:

• Response header check: Check whether HTTP response headers contain CDN-related fields (such as CF-Ray, X-Cache, etc.)
• Latency test: Ping your domain from different regions and compare latency changes before and after acceleration
• API response time: Monitor P95/P99 response times of APIs to see if there is improvement

Recommended tools:

• Pingdom: Test website response speed from multiple locations
• WebPageTest: Run detailed tests from multiple locations worldwide
• Cloudflare Analytics: View request distribution and response times

VII. Points to Note

• Dynamic acceleration ≠ caching: Dynamic content is not cached, and every request goes back to the origin. The origin server needs sufficient processing capacity.
• Cost consideration: Dynamic acceleration is usually billed by request volume or traffic, more expensive than static CDN. When API calls are frequent, costs need to be evaluated.
• SSL/TLS overhead: Dynamic acceleration requires end-to-end encryption, which adds some CPU overhead.
• Use together with static acceleration: It is recommended to use dynamic acceleration for APIs and static caching for images, CSS, and JS. The combination works best.

Dynamic acceleration and static acceleration each have their uses. Choose the appropriate combination based on your actual business scenarios.