Event loop na gudanar da JavaScript dinka a kan thread guda daya, don haka duk wani abu synchronous da ke daukar dogon lokaci yana toshe shi — kuma yayin da aka toshe, Node ba ya bautar wata request, timer, ko callback. Toshewa kusan koyaushe aiki ne na CPU-bound ko *Sync API, ba taba async I/O da aka jira (await) yadda ya kamata ba.
*Sync) API — fs.readFileSync, fs.writeFileSync, child_process.execSync, zlib.gzipSync. Suna jira a wuri guda maimakon mika aikin ga libuv.map/sort/filter a manyan arrays, lissafin matrix, sarrafa hoto/bidiyo, parsing/serializing na manyan structures.JSON.parse / JSON.stringify — synchronous kuma O(n); payload na MB da yawa yana daskarar da loop din tsawon lokacin parse.crypto.pbkdf2Sync, bcrypt a sync mode, hashing manyan buffers a kan main thread.while (true), recursion mara iyaka, for a kan miliyoyin items da aiki ga kowane item.// Duk wadannan suna toshe loop — babu wata request da ake bautarwa a lokacin:
const data = fs.readFileSync("big.json"); // sync I/O
const obj = JSON.parse(hugeString); // babban parse
const hash = crypto.pbkdf2Sync(pw, salt, 1e6, 64, "sha512"); // sync crypto
for (let i = 0; i < 1e9; i++) { /* CPU */ } // matsattsen loop
Nannade aikin CPU a cikin
asyncfunction ba ya taimaka —asyncyana barin sarari ne kawai aawait; jikin synchronous din yana kammalawa duk da haka a kan thread na loop.
perf_hooks.monitorEventLoopDelay() ko libraries kamar blocked-at; karuwar jinkiri na nufin wani abu na hana thread.node --prof, clinic doctor/clinic flame, Chrome DevTools CPU profile domin gano frame na synchronous mai zafi.*Sync call (fs.promises.readFile, crypto.pbkdf2, zlib.gzip).worker_threads pool, child process, ko queue/service na waje.setImmediate/await domin loop ya samu numfashi tsakanin batches.const { Worker } = require("node:worker_threads");
// Sauke hash mai tsada domin loop ya ci gaba da amsawa.
const worker = new Worker("./hash-worker.js", { workerData: { pw, salt } });
A Node, call guda mai toshewa yana hukunta kowane client mai gudana lokaci guda, ba wai kawai request din da ya haddasa shi ba — latency na tashi sama, health checks na kare lokaci, kuma process yana kama da "rataye" karkashin nauyi. Masu tambayoyi suna tambayar wannan domin ganin ko za ka iya ambaton takamaiman masu toshewa (*Sync, babban JSON.parse, sync crypto, ReDoS, CPU loops), gano su da kayan aikin event-loop-lag, da gyara su ta hanyar zuwa async ko sauke aiki zuwa worker threads. Ita ce mafi yawan gazawar aikin Node a production.
Ɗakin karatu na tambayoyin hira na IT tare da amsoshi cikakke — daga Junior zuwa Senior.
Ba da Gudummawa