Distributed rate limiting on Azure with token bucket, sliding window, and fixed window algorithms using Redis Cache for API protection.
Difficulty: beginner
Tags: rate-limiting, api-protection, distributed, redis, azure
A rate limiter protects APIs from abuse and ensures fair resource allocation across clients. This Azure-native design implements multiple algorithms — token bucket for smooth rate limiting, sliding window log for precise counting, and fixed window counter for simplicity. The distributed implementation uses Azure Redis Cache for atomic counter operations across multiple API Management instances, with per-client and per-endpoint configurable limits.