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performance.eventLoopUtilization() in Node.js

Theory

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performance.eventLoopUtilization() in Node.js

performance.eventLoopUtilization() (in node js) is a Node.js topic. In plain words you use it for wait for DB then reply in one Node process. Don’t start with a slogan — start with that picture.

Smallest example: async I/O, don’t block. Type it, run it, and say what you see. If you can do that from memory, you know performance.eventLoopUtilization() (in node js).

From the example next to this theory — performance.

Trap — fs.readFileSync on a huge file. Fix that before you talk about advanced Node.js.

Viva — what is performance.eventLoopUtilization() (in node js)? Then show async I/O, don’t block. Then name the trap.

Exam tip

What is performance.eventLoopUtilization() (in node js)? Show this: async I/O, don’t block. Trap: fs.readFileSync on a huge file.

Example

// performance.eventLoopUtilization() in Node.js
const users = [
  { id: 1, name: "Asha" },
  { id: 2, name: "Ravi" },
];

function findUser(id) {
  return users.find((u) => u.id === id) ?? null;
}

console.log(findUser(2));
console.log(users.map((u) => u.name));

performance.eventLoopUtilization() in Node.js: find user 2, then list names. Say both prints.

Short notes

Defperformance.eventLoopUtilization() (in node js) — wait for DB then reply in one Node process.
Ruleasync I/O, don’t block
Trapfs.readFileSync on a huge file
Useone Node process

// performance.eventLoopUtilization() in Node.js const users = [ { id: 1, name: "Asha" }, { id: 2, name: "Ravi" }, ]; function findUser(id) { return users.find((u) => u.id === id) ?? null; } console.log(findUser(2)); console.log(users.map((u) => u.name));

performance.eventLoopUtilization() in Node.js

Example

Short notes

Questions

performance.eventLoopUtilization() in Node.js

Example

Short notes

Questions