[Solved] You wrote this code snippet to create a cluster but it crashes immediately: const cluster = require('cluster'); cluster.fork(); require('http').createServer((req, res) => res.end('Hello')).... | Node.js

Node.js - Cluster Module

You wrote this code snippet to create a cluster but it crashes immediately:

const cluster = require('cluster');
cluster.fork();
require('http').createServer((req, res) => res.end('Hello')).listen(3000);

What is the likely cause?

AThe worker process does not listen on a port

BMissing a callback function in cluster.fork()

CNot checking cluster.isMaster before forking

DNo error handling for server creation

Step-by-Step Solution

Solution:

Step 1: Analyze cluster usage
The code calls cluster.fork() without checking if (cluster.isMaster). Both master and worker processes fork additional processes and attempt to bind to port 3000, causing port conflicts (EADDRINUSE) and crashes.
Step 2: Identify the problem
The missing if (cluster.isMaster) check before forking leads to repeated forking and server creation attempts, causing the crash.
Final Answer:
Not checking cluster.isMaster before forking -> Option C
Quick Check:
Check cluster.isMaster before fork [OK]

Quick Trick: Always check cluster.isMaster before forking [OK]

Common Mistakes:

Master "Cluster Module" in Node.js

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