Node.js · Theory

Child Process

Theory

19/723

Child Process

Child Process is a Node.js topic. In plain words you use it for use all CPU cores in production box. Don’t start with a slogan — start with that picture.

Smallest example: cluster.fork or PM2. Type it, run it, and say what you see. If you can do that from memory, you know Child Process.

From the example next to this theory — Child Process: find user 2, then list names.

Trap — in-memory session without sticky. Fix that before you talk about advanced Node.js.

Viva — what is Child Process? Then show cluster.fork or PM2. Then name the trap.

Exam tip

What is Child Process? Show this: cluster.fork or PM2. Trap: in-memory session without sticky.

Example

// Child Process
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));

Child Process: find user 2, then list names. Say both prints.

Short notes

DefChild Process — use all CPU cores in production box.
Rulecluster.fork or PM2
Trapin-memory session without sticky
Useproduction box

Node.js · Theory

Child Process

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Theory

19/723

Child Process

Child Process is a Node.js topic. In plain words you use it for use all CPU cores in production box. Don’t start with a slogan — start with that picture.

Smallest example: cluster.fork or PM2. Type it, run it, and say what you see. If you can do that from memory, you know Child Process.

From the example next to this theory — Child Process: find user 2, then list names.

Trap — in-memory session without sticky. Fix that before you talk about advanced Node.js.

Viva — what is Child Process? Then show cluster.fork or PM2. Then name the trap.

Exam tip

What is Child Process? Show this: cluster.fork or PM2. Trap: in-memory session without sticky.

Example

// Child Process
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));

Child Process: find user 2, then list names. Say both prints.

Short notes

DefChild Process — use all CPU cores in production box.
Rulecluster.fork or PM2
Trapin-memory session without sticky
Useproduction box

Child Process

Example

Short notes

Questions

Child Process

Example

Short notes

Questions