Worker threads jippermettu lil Node jexegwixxi JavaScript fuq threads separati b'parallelism veru — jsolvu l-akbar limitazzjoni ta' Node: xogħol CPU-intensive jissiġill il-single main thread (u b'hekk il-requests kollha). Użahom għal komputazzjoni tqila, mhux għal I/O (li l-event loop diġà jittratta effiċjentement).
app.(, {
result = ();
res.(result);
});
Node mexxi l-JS tiegħek fuq thread wieħed. Komputazzjoni sinkrona twila tissiġill kollox — l-event loop ma jistax jipproċessa request oħrajn sakemm jispiċċa. Worker threads jċaqalqu l-xogħol minn-main thread.
// main.js
import { Worker } from "worker_threads";
function runHeavyTask(data) {
return new Promise((resolve, reject) => {
const worker = new Worker("./worker.js", { workerData: data }); // runs on a NEW thread
worker.on("message", resolve); // receive the result
worker.on("error", reject);
worker.on("exit", (code) => { if (code !== 0) reject(new Error(`exit ${code}`)); });
});
}
// the main thread stays free to handle other requests while this runs
const result = await runHeavyTask({ numbers: [...] });
// worker.js — runs in parallel, on its own thread
import { workerData, parentPort } from "worker_threads";
const result = expensiveComputation(workerData); // doesn't block the main thread
parentPort.postMessage(result); // send the result back
Il-worker jaħdem b'mod indipendenti; il-main thread ikompli jservi r-requests u ikseb ir-riżultat permezz ta' messaġġ meta jispiċċa.
✓ USE for CPU-bound work: image/video processing, encryption, compression,
big data parsing, complex calculations, ML inference
✗ DON'T use for I/O (DB, files, HTTP) — the async event loop already handles
that efficiently; a worker would add overhead for no benefit
Ir-regola: workers għal CPU-bound, event loop għal I/O-bound.
worker_threads → share memory (efficient data passing), in-process threads — CPU work
child_process → separate OS processes, run other programs — heavier isolation
cluster → fork the whole server across CPUs — scale request handling
Worker threads jsolvu l-debolezza ċentrali ta' Node — il-kompiti CPU-bound jissiġillu l-event loop ta' thread wieħed u jgħaddsu l-requests konkorrenti kollha.
L-għarfien kif jċaqalqu l-komputazzjoni tqila għal worker (u tilħaqdil-main thread responsiv), u kritikalment meta tużahom (CPU-bound biss, qatt mhux għal I/O), hu dak li jippermettu lil servizz Node jittratta l-ipproċessar tqil ħinijiet b'hekk ma jissikrifikaw il-konkorrenza li tagħmel Node prezjuża.
Għall-pooling ta' workers fil-produzzjoni, libreriji bhal Piscina jmexxu thread pool b'mod effiċjenti.