Cost Optimization & Traffic Management Flashcards

What CDN cost optimization technique involves compressing text-based responses before delivering them to end users?

Answer: Gzip or Brotli compression

Gzip and Brotli compression reduce the byte size of text responses, directly lowering egress data transfer costs.

A media company streams live events globally. Which CDN traffic management strategy best handles sudden audience spikes?

Answer: Multi-CDN failover with auto-scaling

Multi-CDN failover with auto-scaling distributes load across providers and dynamically adjusts capacity, preventing bottlenecks during live event spikes.

Which HTTP header instructs a CDN to NOT cache a response and always fetch fresh content from origin?

Answer: Cache-Control: no-store

Cache-Control: no-store tells both CDN edge nodes and browsers not to store any version of the response, forcing every request to the origin.

A global e-commerce site wants to reduce CDN costs for product images. Which combination of techniques provides the greatest savings?

Answer: Convert images to WebP format and set long cache TTLs

WebP provides superior compression ratios versus JPEG/PNG, and long TTLs maximize cache hit rates, both reducing bytes transferred and origin requests.

What is the primary purpose of CDN traffic shaping in a cost optimization context?

Answer: To prioritize or throttle specific traffic types to control bandwidth costs

Traffic shaping lets CDN operators throttle lower-priority traffic and reserve bandwidth for high-value content, preventing unexpected egress cost overruns.

A SaaS company notices that 40% of their CDN requests return a 404 status for non-existent resources. How does this affect costs?

Answer: It increases costs because 404 responses are typically not cached and hit the origin

Non-cacheable 404 responses cause repeated origin fetches, generating both unnecessary egress charges and origin compute costs.

Which CDN feature enables serving different content variants (e.g., mobile vs. desktop) from cache without separate origin requests for each?

Answer: Vary header-based caching

The Vary header instructs the CDN to cache separate versions of a response per header value (e.g., User-Agent), serving the correct variant from cache.