@lde/host-limiter

Zero-dependency scheduling primitive for outbound work: a concurrent map bounded by a global cap and a per-host cap, with results in input order and no head-of-line blocking – a saturated host yields to items on other hosts rather than stalling the queue.

Installation

npm install @lde/host-limiter

import { hostKeyOf, mapHostLimited } from '@lde/host-limiter';

const responses = await mapHostLimited(
  urls,
  urls.map(hostKeyOf),
  8, // at most 8 requests in flight overall
  2, // at most 2 against any one host
  async (url) => fetch(url).catch((error) => error),
);

Documentation

See the full documentation.