Glossary

token bucket

A limiter that refills tokens at a fixed rate; a request spends one token or is rejected.

A bucket holds up to CAP tokens and refills at RATE tokens per second. Admitting a request costs one token; an empty bucket rejects. Confusions: unlike a fixed window it permits short bursts up to CAP, and unlike a leaky bucket it does not smooth output to a constant rate.

Also: token buckets