Panduan praktis untuk menangani kebocoran memori di Node.js

Apa itu kebocoran memori?

Manajemen memori

• . . . , . C C++. , , malloc free, .
• . , , , . , , , . , , , , . . — JavaScript, , JVM (Java, Scala, Kotlin), Golang, Python, Ruby .
• Penerapan konsep kepemilikan memori. Dengan pendekatan ini, setiap variabel harus memiliki pemiliknya sendiri. Segera setelah pemilik berada di luar ruang lingkup, nilai dalam variabel dihancurkan, membebaskan memori. Ide ini digunakan di Rust.

Pengumpulan sampah JavaScript

Memori bocor di aplikasi Node.js

▍ Keakraban dengan kode yang memiliki kebocoran memori

const express = require('express')

const app = express();
const port = 3000;

const leaks = [];

app.get('/bloatMyServer', (req, res) => {
  const redundantObj = {
    memory: "leaked",
    joke: "meta"
  };

  [...Array(10000)].map(i => leaks.push(redundantObj));

  res.status(200).send({size: leaks.length})
});

app.listen(port, () => console.log(`Example app listening on port ${port}!`));

▍Panggil kebocoran memori

▍ Heap Dump

npm i heapdump

const express = require('express');
const heapdump = require("heapdump");

const app = express();
const port = 3000;

const leaks = [];

app.get('/bloatMyServer', (req, res) => {
  const redundantObj = {
    memory: "leaked",
    joke: "meta"
  };

  [...Array(10000)].map(i => leaks.push(redundantObj));

  res.status(200).send({size: leaks.length})
});

app.get('/heapdump', (req, res) => {
  heapdump.writeSnapshot(`heapDump-${Date.now()}.heapsnapshot`, (err, filename) => {
    console.log("Heap dump of a bloated server written to", filename);

    res.status(200).send({msg: "successfully took a heap dump"})
  });
});

app.listen(port, () => {
  heapdump.writeSnapshot(`heapDumpAtServerStart.heapsnapshot`, (err, filename) => {
    console.log("Heap dump of a fresh server written to", filename);
  });
});

▍ Deteksi kebocoran memori

curl --location --request GET 'http://localhost:3000/heapdump'

▍Fiks memori bocor

app.get('/bloatMyServer', (req, res) => {
  const redundantObj = {
    memory: "leaked",
    joke: "meta"
  };

  const leaks = [];

  [...Array(10000)].map(i => leaks.push(redundantObj));

  res.status(200).send({size: leaks.length})
});

Ringkasan