CDN Multi-CDN Strategy & Failover 5

Question 1

A financial services firm requires that its multi-CDN failover completes within 30 seconds of detecting a CDN failure. Which combination of settings best achieves this?

Accepted Answer

DNS TTL of 30s + health check interval of 10s with 3-failure threshold

Answer

A 30-second DNS TTL and 10-second health check interval with a 3-failure threshold allows failover detection and DNS propagation to complete within the 30-second SLA window.

Question 2

Which approach best prevents cache poisoning attacks when operating a multi-CDN environment with multiple origin-pull paths?

Accepted Answer

Validate all origin responses with TLS certificate pinning and enforce strict Cache-Control headers

Answer

TLS certificate pinning between CDN and origin verifies server identity, while strict Cache-Control headers prevent unauthorized content from being cached and served.

Question 3

A multi-CDN deployment uses JavaScript-based RUM to measure CDN performance. Which limitation must operators account for when using this approach?

Accepted Answer

RUM data is skewed by users with ad blockers or script-blocking browser extensions who may not report metrics

Answer

Ad blockers and privacy tools often block RUM beacon requests, creating a self-selection bias where performance data underrepresents a subset of users.

Question 4

What is the purpose of 'last-resort' origin failover configuration in a multi-CDN architecture?

Accepted Answer

To ensure user requests reach the origin server directly if all CDN providers simultaneously fail

Answer

A last-resort origin failover path guarantees site availability even in catastrophic multi-CDN failure scenarios by allowing direct origin access.

Question 5

A multi-CDN operator wants to test failover procedures without impacting production users. Which technique allows this?

Accepted Answer

Simulate failover in a staging environment with identical CDN configurations and traffic patterns mirrored from production

Answer

A staging environment with mirrored production CDN configurations allows realistic failover testing without risking real user sessions.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN Multi-CDN Strategy & Failover 5