What is the primary purpose of rate limiting in a system?

What is the primary purpose of rate limiting in a system?

• A. It is used to ensure every request is logged.
• B. It restricts how many requests a client can make in a given time window to prevent abuse.
• C. It guarantees 100% availability.
• D. It caches all responses to reduce load.

Answer: (B)

Rate limiting is about controlling how frequently a client can send requests in a given time window. The goal is to prevent abuse and overload, preserving performance, fairness, and stability for everyone. When a client hits the limit, further requests are rejected or delayed, which provides backpressure that helps the service recover and continue serving others. This differs from logging, which is for auditing and visibility, and from caching, which stores answers to reduce repeated work. Rate limiting cannot guarantee 100% availability; it helps protect availability under heavy load but may cause temporary rejections to keep the system healthy.

Rate limiting is about controlling how frequently a client can send requests in a given time window. The goal is to prevent abuse and overload, preserving performance, fairness, and stability for everyone. When a client hits the limit, further requests are rejected or delayed, which provides backpressure that helps the service recover and continue serving others.

This differs from logging, which is for auditing and visibility, and from caching, which stores answers to reduce repeated work. Rate limiting cannot guarantee 100% availability; it helps protect availability under heavy load but may cause temporary rejections to keep the system healthy.