Hello Everyone, I want to know how are ‘Child Threads’ handled in Node.js? In my previous interview, I have faced this question but I didn’t know the answer. Can anyone knows these query and help me out or suggest some node.js based interview questions as a beginner point.

Arjunkumar09:
Hello Everyone, I want to know how are ‘Child Threads’ handled in Node.js? In my previous interview, I have faced this question but I didn’t know the answer. Can anyone knows these query and help me out or suggest some node.js based interview questions as a beginner point.

pls i dont get your question child thread asin how pls put code so we can understand or explain further with some code am willing to help but i just dont get ure question

peterincredible:
pls i dont get your question child thread asin how pls put code so we can understand or explain further with some code am willing to help but i just dont get ure question

^ The question albeit a very advanced part of javascript, is pretty clear and straightforward.

Nodejs doesn't allow the users interfere and mess with the running of child threads. By default, it is a single-thread non-blocking runtime, as we all know.
However, if there is a need to perform any asynchronous I/O task, then Node.js can spawn child-threads.
You can invoke this though, using the 'child-process' module that comes with Node.

I did something like this a while back:

const oldSpawn = childProcess.exec;
childProcess.exec = () => {
Logger.info('spawn called');
Logger.info(arguments);
return oldSpawn.apply(this, arguments);
};

It relies heavily on the child_process.spawn() command and take note, this doesn't block the event loop in any way.
If you wanted to run shell commands in between Node js operations, then you can spawn a child process and use the exec command. I see people do this a lot:

import { execSync } from 'child_process';
execSync .. blah blah blah

Take note, that execSync will block the event loop. Although, it is very good for automating shell scripts.

You could also fork a child, (child_process.fork()), which will create a communication channel between them both i.e parent and child.

=======

I hope I have been of service to you. Cheers.

p.s.: contact me and I can schedule a mock interview for you.

makavele:


^ The question albeit a very advanced part of javascript, is pretty clear and straightforward.

Nodejs doesn't allow the users interfere and mess with the running of child threads. By default, it is a single-thread non-blocking runtime, as we all know.
However, if there is a need to perform any asynchronous I/O task, then Node.js can spawn child-threads.
You can invoke this though, using the 'child-process' module that comes with Node.

I did something like this a while back:




It relies heavily on the child_process.spawn() command and take note, this doesn't block the event loop in any way.
If you wanted to run shell commands in between Node js operations, then you can spawn a child process and use the exec command. I see people do this a lot:



Take note, that execSync will block the event loop. Although, it is very good for automating shell scripts.

You could also fork a child, (child_process.fork()), which will create a communication channel between them both i.e parent and child.

=======

I hope I have been of service to you. Cheers.

p.s.: contact me and I can schedule a mock interview for you.

I will love to take you up on this offer in a couple of months

crownedrookie:

I will love to take you up on this offer in a couple of months

You're welcome in advance

makavele:


You're welcome in advance

What kind of work are you into currently if I may ask bro

crownedrookie:

What kind of work are you into currently if I may ask bro

Software Engineering :: Technical Lead

makavele:


Software Engineering :: Technical Lead

i sent a message to u on watsapp

^ Whatsapp ke??

I sent you a PM . . check your Nairaland associated email . .

Arjunkumar09:
Hello Everyone, I want to know how are ‘Child Threads’ handled in Node.js? In my previous interview, I have faced this question but I didn’t know the answer. Can anyone knows these query and help me out or suggest some node.js based interview questions as a beginner point.

Node.js, in its essence, is a single thread process. It does not expose child threads and thread management methods to the developer. Technically, Node.js does spawn child threads for certain tasks such as asynchronous I/O, but these run behind the scenes and do not execute any application JavaScript code, nor block the main event loop.

If threading support is desired in a Node.js application, there are tools available to enable it, such as the ChildProcess module.

Also, here we have listed node.js interview questions:

Question: Explain the basics of Node.js.
Question: How are ‘Child Threads’ handled in Node.js?
Question: State some differences between Angular JS and Node.js.
Question: State the primary uses of Node.js.
Question: What is Event-Driven programming?
Question: In the context of Node.js, what is REPL?
Question: What is a test pyramid in Node.js?
Question: What is libuv?
Question: Is Node.js the best platform for CPU-heavy applications?
Question: What is the purpose of the Express JS Package?
Question: What are LTS versions of Node.js?
Question: Explain the working of assert in Node.js
Question: What is callback hell?
Question: What is stub in Node.js?
Question: What is Event Loop?
Question: What is stream in Node.js? What are its types?
Question: List and explain the timing features of Node.js.
Question: Highlight the differences between process.nextTick() and setImmediate().
Question: Explain readFile and createReadStream in Node.js.
Question: Does Node.js provide a Debugger?
Question: Describe the exit codes in Node.js.
Question: Why is NODE_ENV used?
Question: What is Event Emitter in Node.js?
Question: What is Punycode?
Question: Explain the concept of JIT and highlight its relation with Node.js.
Question: Why is the buffer class used in Node.js?
Question: What is the difference between fork () and spawn () methods in Node.js?
Question: State the steps to write an Express JS application.
To get the answer to these questions you can [url="https://hackr.io/blog/node-js-interview-questions"]follow us[/url].

The os and cluster core module can also handle child processes.However, unlike the core child-process module, the child process can't communicate with the parent process.
Here is how it is implemented:

var cluster = require('cluster');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {

console.log('I am the master/parent process launching workers!');

for(var i = 0; i < numCPUs; i++) {cluster.fork();} }
else {
console.log('I am a fork/child process'); //perform child operations }

@rohanjoshi0894

Stop pasting google answers.
Show that you really know nothing about the subject in question.

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