Rate Limiting - Simplified

What is rate limiting ?

Nothing, but a technique to protect a system from excessive or malicious requests that could overload servers, degrade performance, or lead to denial-of-service (DoS) attacks.

HTTP Response Status Code 429. Read more.

Image Credits: https://www.wallarm.com/what/rate-limiting

Token bucket algorithm

The token bucket algorithm is widely used for rate limiting. It is straightforward, easily understood, and frequently utilized by online businesses.

Following is how the token bucket algorithm operates:

• A container with a predetermined capacity is called a token bucket.
• Periodically, tokens are added to the bucket at predetermined rates.
• No additional tokens are added to the bucket after it is full.
• Every second, the re-filler adds 2 tokens to the bucket. Extra tokens will spill out once the bucket is full.