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How do you limit the concurrency of many async operations (p-limit / promise pool)?

Q: How do you limit the concurrency of many async operations (p-limit / promise pool)?

**TL;DR.** Firing thousands of promises at once exhausts sockets, memory, or hits rate limits. A **concurrency limiter** (like p-limit , or a manual pool) caps how many run **simultaneously**, starting the next only as a slot frees up — bounding resource use while keeping throughput high. 1000 tasks waiting limit = 5 5 run at once <path class='d-edge-accent' d='M294 80 H

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Bounding parallelism to avoid overwhelming resources.

nodejsconcurrencyasyncp-limit

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Cap concurrent fetches at 5

import pLimit from 'p-limit';
const limit = pLimit(5);              // at most 5 in flight

const results = await Promise.all(
  urls.map((url) => limit(() => fetch(url).then(r => r.json())))
);
// 1000 URLs, but never more than 5 concurrent requests.

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