Advanced Rate Limiting and API Throttling Architecture

Develop a sophisticated rate limiting middleware for a high-traffic API that supports dynamic throttling based on user roles, IP reputation, and request complexity. Implement a distributed rate limiting solution using Redis that can handle concurrent requests across multiple server instances. Include features like sliding window rate limiting, adaptive throttling based on server load, and detailed logging of throttled requests. Create a mechanism to provide meaningful HTTP 429 responses with retry-after headers and graceful degradation.