CDN API Gateway & Rate Limiting 5

Question 1

When a CDN API gateway returns an ETag header with an API response, what rate limiting benefit does client-side caching provide?

Accepted Answer

It reduces redundant API calls by allowing conditional GET requests, preserving quota

Answer

Clients using ETags with If-None-Match can receive 304 Not Modified responses, avoiding full API calls and conserving their rate limit quota.

Question 2

Which API gateway strategy helps prevent a 'noisy neighbor' tenant from degrading CDN API performance for other tenants?

Accepted Answer

Per-tenant rate limit isolation with dedicated counters

Answer

Per-tenant isolation ensures one high-traffic tenant's rate limit counters do not affect other tenants' quotas or performance.

Question 3

An API gateway uses GraphQL instead of REST. Which rate limiting dimension is most important to add beyond simple request count?

Accepted Answer

Query complexity or depth scoring

Answer

GraphQL queries can vary enormously in compute cost, so complexity or depth scoring prevents cheap request counts from hiding expensive query execution.

Question 4

What is the role of a 'developer portal' in a CDN's API gateway ecosystem?

Accepted Answer

To provide documentation, API key management, and quota dashboards to API consumers

Answer

A developer portal gives external consumers self-service access to API documentation, key generation, and usage/quota monitoring.

Question 5

A CDN API gateway needs to enforce rate limits even during a Redis cluster failover. Which approach maintains availability?

Accepted Answer

Fall back to local in-memory approximate rate limiting per node

Answer

Falling back to local in-memory counters provides approximate rate limiting continuity during a distributed cache outage instead of fully blocking traffic.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN API Gateway & Rate Limiting 5