Evaluate the implementation of a distributed rate limiter for a public API using the 'Token Bucket' and 'Leaky Bucket' algorithms utilizing Redis as the backing store. Provide a detailed comparison focusing on memory consumption, computational overhead, and traffic burst handling. Write a detailed technical specification for a 'Fixed Window Counter' approach optimized for high concurrency, including how to handle race conditions using Redis Lua scripting to ensure atomicity. Discuss the pros and cons of this approach compared to the Sliding Window Log.