Rate Limiting: The Token Bucket Algorithm

Rate limiting is a crucial component in system design to prevent abuse and ensure fair usage of resources. One of the most popular algorithms is the Token Bucket.

How it Works

Imagine a bucket that holds tokens. Tokens are added to the bucket at a fixed rate (e.g., 10 tokens per second). The bucket has a maximum capacity.

• When a request arrives, it must consume a token to be processed.
• If the bucket has tokens, one is removed, and the request is allowed.
• If the bucket is empty, the request is dropped or queued.

Visualization

Below is a visualization of the Token Bucket algorithm.