Forking workers per CPU core in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the cluster module.

Node.js

const cluster = require('[1]');

Drag options to blanks, or click blank then click option'

Ahttp

Bcluster

Cos

Dfs

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'os' instead of 'cluster' to import the cluster module.

Forgetting to import the cluster module.

The cluster module is imported using require('cluster') to enable forking workers.

2fill in blank

medium

Complete the code to import the OS module.

Node.js

const os = require('[1]');

Drag options to blanks, or click blank then click option'

Aos

Bcluster

Chttp

Dpath

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'cluster' instead of 'os' to import the OS module.

Confusing 'os' with 'http' or 'path'.

The os module is imported using require('os') to access CPU core information.

3fill in blank

hard

Fix the error in the code to get the number of CPU cores.

Node.js

const numCPUs = os.[1]();

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AcpuCount

Bcores

CcpuCores

Dcpus

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent method like 'cpuCount' or 'cores'.

Forgetting the parentheses after the method name.

The correct method to get CPU cores is os.cpus(), which returns an array of CPU info.

4fill in blank

hard

Fill both blanks to fork a worker for each CPU core.

Node.js

if (cluster.[1]) {
  for (let i = 0; i < numCPUs.[2]; i++) {
    cluster.fork();
  }
}

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AisPrimary

Blength

CisMaster

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'isMaster' instead of 'isPrimary'.

Using 'count' or 'size' instead of 'length' for array length.

Use cluster.isPrimary to check if the process is the primary one, and numCPUs.length to get the number of CPU cores.

5fill in blank

hard

Fill all three blanks to log when a worker exits and fork a new one.

Node.js

cluster.on('[1]', (worker, code, signal) => {
  console.log(`Worker ${worker.[2] died`);
  cluster.[3]();
});

Drag options to blanks, or click blank then click option'

Aexit

Bpid

Cfork

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'disconnect' or 'close' instead of 'exit' event.

Using 'id' or 'workerId' instead of 'pid' for worker identifier.

Using 'spawn' or 'create' instead of 'fork' to start a new worker.

The event to listen for is 'exit'. The worker's process ID is accessed with worker.pid. To create a new worker, call cluster.fork().