Multi-CDN - CDN Planet

Multi-CDN means using two or more content delivery networks for your website, app or video service, primarily to improve performance. Big brand websites and streaming services like Linkedin, Etsy, Spotify and TikTok have been doing Multi-CDN for many years.

Different companies use different Multi-CDN architectures. For example, Amazon.com uses their three CDNs to deliver dynamic and static content, while TikTok in US uses only Akamai for dynamic traffic plus many other CDNs for delivery of the website images and videos.

What are the key benefits of Multi-CDN? Which challenges will you most likely run into going from one CDN to Multi-CDN? Should you build your own traffic routing system or use the platform of a solution provider?

Benefits of Multi-CDN

Multi-CDN helps you reduce CDN costs and improves the speed and availability of your website, app or video, resulting in happier users and higher business outcomes.

Lower Costs

Escape vendor lock-in and negotiate better pricing

Prevent high overage fees

Enjoy the best rate in every region

Better Performance

Work around (local) outages and CDN failures

Reduce response times and buffering

Handle traffic spikes without issues

Challenges

While Multi-CDN may bring you significant benefits, it can also be challenging to implement and operate. The most common and biggest challenges that come with Multi-CDN are Feature parity, Security, Observability and DevOps.

Feature Parity

Caching, origin shield, header injection, redirects, custom error pages, etc. Getting multiple CDNs to behave the same can be hard.
You may require custom CDN configs (managed by the CDN providers) or edge compute/workers (managed by you) to bridge the gaps.

Document your CDN behavior requirements before evaluating CDNs and Multi-CDN solutions

DevOps

Most Multi-CDN architectures require on-going attention and work: observing traffic, analyzing CDN behavior and tuning for optimal costs and performance. This can potentially be very time consuming and may require skills and knowledge that are currently not available in your teams.

Take your time to assess the impact on your teams when evaluating Multi-CDN solutions

Security

Blocking malicious traffic on all your CDNs may be your biggest challenge with Multi-CDN.
How do you implement custom WAF rules, global rate limiting and content theft protection across multiple CDNs, so security is consistent and effective, all the time?

Write up your must-have and should-have security requirements

Observability

Staying on top of CDN security events, data transfer & requests, cache hit ratio and performance can be hard when using multiple CDNs: you may need to build multiple, complex data ingestion and transformation pipelines because of a lack of uniformity in CDN access logs and API data.

Know what CDN data you need, who needs to use it and when

Solution Providers

Don't want to build your own Multi-CDN system?

Unified platform. Intelligent, automatic failover. No extra latency.

Learn more about IO River

Other Providers

NS1, Netscaler and DigiCert provide Multi-CDN solutions powered by real user measurements.