What is API Rate Limiting?

API rate limiting is a technique used to control the amount of traffic an API can handle over a given period. It is essential for maintaining the performance, reliability, and security of the API by ensuring that it is not overwhelmed with too many requests at once.

Why Rate Limiting is Important:

1. Prevents Overload: It protects the API from being flooded with excessive requests, which could slow down or crash the system.

2. Fair Usage: Ensures that all users get an equal chance to use the API without one user monopolizing resources.

3. Improves Security: Helps protect against DoS (Denial of Service) attacks, where an attacker might try to overwhelm the system by sending too many requests.

Common Rate Limiting Strategies:

1. Fixed Window: A set number of requests allowed within a fixed time window (e.g., 100 requests per minute).

2. Rolling Window: A more dynamic approach that allows a set number of requests over a rolling time window (e.g., 100 requests in the last 60 minutes).

3. Token Bucket: Tokens are added at a fixed rate to a "bucket," and each request consumes a token. If the bucket is empty, requests are limited.

4. Leaky Bucket: Similar to the token bucket but ensures a smooth outflow of requests at a fixed rate.

When to Use Rate Limiting:

If your API serves a large number of users or handles sensitive data, rate limiting should be implemented to ensure it remains performant, secure, and reliable.