Rate limiting

feature: ratelimit

Enable

churust = { version = "0.3", features = ["ratelimit"] }

Install

GCRA-based limiting — bursts are smoothed and Retry-After is exact rather than estimated:

#![allow(unused)]
fn main() {
use std::time::Duration;

.install(
    RateLimit::per_minute(60)
        .burst(10)
)
}

Helpers: RateLimit::per_second, per_minute, per_hour, or RateLimit::per(limit, period).

Keying

By default keys use the peer address. IPv6 peers are bucketed by network prefix (typically /64), because a subscriber is handed a whole prefix and limiting each address separately limits nobody.

Custom keys (return None to skip limiting for that request):

#![allow(unused)]
fn main() {
.install(
    RateLimit::per_minute(60).by(|call| {
        // e.g. API key header
        call.header("x-api-key").map(str::to_owned)
    })
)
}

Tuning

API reference

• docs.rs/churust-ratelimit