CDN Edge Computing & Edge Functions 4

Question 1

What is WebAssembly (Wasm) used for in edge computing environments?

Accepted Answer

Running code compiled from languages like Rust or C at near-native speed inside edge sandboxes

Answer

Wasm allows high-performance, sandboxed execution of code written in systems languages, expanding the set of workloads suitable for edge functions.

Question 2

Which of the following is a key limitation of edge functions compared to traditional server-side applications?

Accepted Answer

They typically have restricted CPU time limits and cannot run long-lived background processes

Answer

Edge functions have strict CPU time budgets (often milliseconds) and are not designed for long-running or stateful background workloads.

Question 3

What is 'origin shield' and how does it interact with edge functions?

Accepted Answer

A designated mid-tier PoP that consolidates cache misses from all edge nodes before hitting origin, reducing origin load

Answer

Origin shield acts as a second caching layer between edge PoPs and the origin, so cache misses from hundreds of edges are funneled through one shield node.

Question 4

How do edge functions typically handle authentication tokens such as cookies without violating the CDN's caching model?

Accepted Answer

By stripping cookies before caching and re-attaching or validating them using the edge function

Answer

A common pattern is to strip auth cookies at the edge, serve a cached response, and then use the edge function to re-inject user-specific data or validate the token before delivery.

Question 5

Which standard API do Cloudflare Workers and other edge platforms expose for making outbound HTTP calls from an edge function?

Accepted Answer

The Web Fetch API (fetch())

Answer

Edge function runtimes implement the Web Fetch API (same as browsers) for making outbound HTTP requests, keeping the API surface standard and portable.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN Edge Computing & Edge Functions 4