Which out-of-the-box policy safeguards against Denial of Service type attacks?

• A. Throttling
• B. Rate limiting
• C. Caching
• D. Circuit Breaker

Answer: (B)

Controlling how fast clients can send requests is the key defense against a flood of traffic. Rate limiting sets a hard cap on how many requests a given client (by IP, API key, or user) can make in a defined time window. When the limit is reached, further requests are blocked or delayed, which prevents resource exhaustion and keeps the service available for legitimate users. This direct throttle on incoming load is what makes rate limiting the most effective out-of-the-box safeguard against Denial of Service-type attacks.

Throttling is related but can be more about pacing or shaping traffic rather than enforcing a strict, global cap. Caching helps reduce load by serving already-seen responses, but it doesn’t stop a flood of requests from reaching the system. Circuit breakers protect downstream services from cascading failures, not from overwhelming traffic.