Master and worker processes in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the role of the master process in Node.js cluster?

The master process manages worker processes. It creates, monitors, and distributes tasks to workers to balance the load.

beginner

What is a worker process in Node.js cluster?

A worker process is a child process created by the master. It runs the application code and handles incoming requests.

intermediate

How do master and worker processes communicate in Node.js?

They communicate using an internal messaging system with events and messages passed between the master and workers.

beginner

Why use master and worker processes in Node.js?

To use multiple CPU cores efficiently by running multiple instances of the app, improving performance and reliability.

intermediate

What happens if a worker process crashes in a Node.js cluster?

The master detects the crash and can automatically create a new worker to replace it, keeping the app running smoothly.

What does the master process do in a Node.js cluster?

A Stores data in a database

B Handles all HTTP requests directly

C Runs the user interface

D Creates and manages worker processes

The master process creates and manages worker processes to distribute workload.

How many worker processes can a Node.js cluster have by default?

A Unlimited without limits

B Only one

C One per CPU core

D Exactly two

By default, the cluster module creates one worker per CPU core to maximize resource use.

What happens when a worker process crashes in a cluster?

A The whole application stops

B The master can restart a new worker

C Nothing, the worker stays crashed

D The master process crashes too

The master process listens for worker exit events and can restart workers automatically.

Which module in Node.js helps create master and worker processes?

A cluster

B http

C fs

D events

The cluster module is designed to create and manage master and worker processes.

How do master and worker processes share workload?

A Master distributes incoming connections to workers

B Workers share memory directly

C Master runs all code, workers idle

D Workers communicate with each other directly

The master process distributes incoming connections to worker processes to balance load.

Explain how master and worker processes work together in Node.js cluster.

Think about who manages and who does the work.

Describe what happens when a worker process crashes and how the cluster handles it.

Focus on fault tolerance and recovery.