Scaling your Node.js app using the "cluster" module

[@AshrafulFerdousFariv]

from version 18.14.0, it is advised to use os.availableParallelism() instead of os.cpus().length

[@SoftwareDeveloperDiaries]

Thanks for the hint!

[@KinoPM2]

Are you looking for job in Crypto Project? MERN

[@vivekbhatti]

Yes i am ​@@KinoPM2

[@moveonvillain1080]

​@@KinoPM2 Hire me 😅

[@sergiobenitez1468]

this playlist is a goldmine

[@SoftwareDeveloperDiaries]

Thanks mate!

[@samworldpk]

using this in production with AWS LB and 2 ec2 instances of 4cores and the results are extremely impressive, now downtimes or performance issues in past 5 years.

[@AlexanderWunschik]

This is super exciting and promising. Thanks for the excellent introduction!

[@AbdulHannan-or8ql]

Hi! Your approach by identifying a problem and then solving it is blazingly great 😃 But please make a video on Difference between Cluster and Multi threads? As both utilizing all cpu cores I am looking forward to hear from you

[@kooshaforoughi8778]

Man i love your videos, you're a very good teacher, you teach advanced topics clearly and with ease. thank you for teaching me! keep going!

[@SoftwareDeveloperDiaries]

Glad to hear that! 🤓

[@vardaanaashish6753]

This was wonderfully explained!

[@maximus4510]

GOSH, I love this channel! And how your deliver the concept clearly and precisely. Thanks!!

[@SoftwareDeveloperDiaries]

Super happy to hear that you enjoy the content, my friend! ☺

[@MelroyvandenBerg]

Keep in mind cluster is not core-pinning.. It just run on whatever core/thread it would like. Also you can still combine the nodejs cluster feature with workers, which in bigger calculations might help to un-block the main thread. Since nodejs is semi-multithreaded by default.

[@MelroyvandenBerg]

also when running this cluster setup you can't share memory, it will just spawn new processes of NodeJS.

[@SoftwareDeveloperDiaries]

Great point!

[@AViStudioMoldova]

Very clean and good explanation! You're good! Keep going! Thanks!

[@chafroudiyed9301]

it is the best video of advanced nodejs i ever seen , keep going

[@SoftwareDeveloperDiaries]

Will do, my friend!

[@Ad9911io]

My team lead explained me about clustering a few times and i didn't get shit, it sounded like a super complex thing when he talked about it. Your explanation was super easy to understand!! Thanks alot!

[@SoftwareDeveloperDiaries]

Really happy to hear that! Keep it up mate!

[@renzcarlosalanga6077]

why? clustering means exactly what it means in the dictionary LOL what's hard about that

[@Ad9911io]

@@renzcarlosalanga6077 So what you're doing here? Just check the dictionary.

[@deepakkewalramani08]

Great explained 👏

[@lautarogabrielgonzalezscho1177]

Amazing information, thanks for sharing!

[@mowmiadrian8608]

Bro, I love it when I find a gem like this. Thank you, I was looking for a quality this channel has to offer for very long time. I'm definitely going to subscribe!

[@SoftwareDeveloperDiaries]

Thanks for joining the channel, my friend! Happy to hear you like it! :)

[@bryannsi]

amazing video, and very well explanation

[@wasankds777]

Thanks a lot, This is what I looking for.

[@SoftwareDeveloperDiaries]

Glad I could help!

[@hashcode01]

Thank you for the clear explanation. One thing to note is that a single instance still utilizes multithreading for asynchronous operations with libuv. Cluster is advantageous for synchronous operations, as shown in your example.

[@anton1492]

your videos are awesome man! i usually don't write comments but your channel is so undersubscribed!

[@SoftwareDeveloperDiaries]

I appreciate that, my friend :)

[@PaweGradziel]

Looks really great! Thanks for the video!

[@SoftwareDeveloperDiaries]

Thanks mate! 😉

[@DudnikAndrey]

Thank you! Very clear explanation

[@SoftwareDeveloperDiaries]

Always welcome!

[@lexNwimue]

Great content man. Great channel

[@SoftwareDeveloperDiaries]

Thanks mate!

[@shinmini99]

omg, bless you.

[@aliadel1723]

can you talk about batch processing in nodejs

[@enogratechnologies1896]

Great video

[@ranadenish]

Can we use cluster module for "SMPP Protocol" faster performance? SMPP is stateful connections, so I am not getting the full output using cluster, any hint?

[@mrlectus]

What is the difference between loadtest vs ab (apache bench) when i use loadtest The total errors was 500+ but with ab i didn't get any errors and i passed in the same metric as you did. This was an on code without cluster

[@tryzack]

hi, i have a problem here, I've done everything like in the video but the workers wont work? the loadtest was arguably the same as the first time, so to check by myself i made another route without any load to check if i could make a get from that one while the heavy one was still loading and the answer was no, it waits for heavy get to complete before actually doing the main get, its like everything was going to the same worker instead of trying to use different workers, i have 12 cores so it should work...

[@saurabhtalele1537]

Thanks nice.... I just want to ask in one core there are multiple processes....or processes is equal to core. ??? Thanks

[@SoftwareDeveloperDiaries]

By default - no, everything will run on a single core. But with the cluster mode - yes.

[@labidyramzi4840]

Question: Can we achieve Node app horizontal scalability(running node on multiple CPU) with only docker and kuburnetes ?

[@SoftwareDeveloperDiaries]

In theory yes, but I wouldn't suggest combining them. If your application is relatively simple and you prioritize simplicity, Node.js cluster mode may be suitable. If you need advanced orchestration, infrastructure flexibility, and are planning for future growth, Kubernetes might be the better option. Ultimately, the decision depends on your specific use case, requirements, and the resources available to your team.

[@fendipratama4792]

thank you for your sharing master, I have a question 'if I have 3 servers, running index.js from each server, how to execute index.js from different server?' any response will be highly appreciated

[@KaleesM-tm4lw]

That's why he said once you start your node server by running the node index.js. the node master will distribute the request across multiple instances which you've already spawned... So NVM about which server you wanna to run...

[@prokhorov_sergey_igorevich]

If we have 8 cpu, the primary script use 1 cpu and remain 7 for the application? Conclusion, if we have 2 cpu - it's doesn't work?

[@code_react]

Ok this is very awesome. I have been watching all of other videos on your channel and trust me your videos convinced me to subscribe to your channel. I can't wait to see more topics like this. And many many thanks for taking your time to make these videos.

[@SoftwareDeveloperDiaries]

Thanks for such nice words, my friend!

[@KinoPM2]

Any way to not reconnect to MongoDB in each cluster ?

[@sanjayms-so9wq]

helpful

[@ArshRadhanpura]

does it make sense to use this with docker and kubernetes?

[@oliverhsu9465]

With containerization, you just add more replicas.

[@carlosflores4179]

How does pm2 know that it should run in cluster mode instead of fork mode?

[@SoftwareDeveloperDiaries]

PM2 uses a configuration file called "ecosystem.config.js" (or "pm2.config.js") to specify exactly that

[@vaibhavm1986]

Hi , Thanks I am looking something similar , just want to understand , making clustering this way , or having replica instances via docker , is there any difference between or better as compared to other what is the recommended way ?

[@SoftwareDeveloperDiaries]

That’s a great question. In theory both approaches allow the so called “horizontal scaling”. When going with Node.js clusters, you’re limited to one machine your cluster is running on. So it’s not optimal for complex apps with very heavy loads, since this machine will be the single point of failure. Node.js cluster is a good idea if you have obvious parallel processing scenarios. However, if you have a complex application that requires multiple machines deployed across multiple environments for example, then Docker can be a better choice. At the end of the day, you can actually try combining them. Run a Node.js cluser on multiple Docker instances.

[@vaibhavm1986]

Thanks 🙂

[@HelloWorld-ow1dh]

i'm getting about ~250 errors even after use of cluster , before it was around ~600, how are you achieving 0 ?

[@internetexplorer7880]

Wait i thought pm2 spawns only 1 if you use that command

[@aka.theos.]

Is there any reason why to use this instead of docker and a load balancer ?

[@SoftwareDeveloperDiaries]

Great question. I would use Node.js "cluster" mode when you have a simple application on a single server and want to scale it horizontally across CPU cores for improved performance. But choose Kubernetes with Docker and Load Balancing when dealing with complex, distributed applications that require container orchestration, horizontal scaling across multiple servers, and advanced features like automatic scaling, rolling updates, and service discovery. It's well-suited for cloud-native architectures.

[@aka.theos.]

@@SoftwareDeveloperDiaries Your content is really good I hope you continue to cover advanced topics because not many channels cover them in details like you do

[@roonywalsh8183]

​@@SoftwareDeveloperDiaries would making a Nodejs cluster in each docker instance be a good idea. Wouldn't it lead to optimization of each server's usage

[@DmitryHolubev]

Hey! What service do you use to create such a good diagrams?

[@SoftwareDeveloperDiaries]

Excalidraw :)

[@TuanPham-ph6lr]

Execuse me, I am new with Nodejs so I have a question, the cpu count is the cpu of the server or cpu of user's computer ? Hope you response me soon.

[@SoftwareDeveloperDiaries]

Hello there! The answer is: the CPU count on the machine that the Node.js app is running on. You’ll be most likely deploying it on the server at the end of the day, so it’s the one that really counts.

[@hakanangin]

Hi, thanks you explanation. I take an error when runing loadtest. What is problem? Error is = node:events:491 throw er; // Unhandled 'error' event ^ Error: read ENOTCONN

[@SoftwareDeveloperDiaries]

Is there anything else that the error message says? Have you made sure that in package.json you "type": "module" like in the video? I've googled the error and it seems like it's mostly caused by another process running on the same port.

[@mjprakash1780]

@@SoftwareDeveloperDiaries facing same issue

[@korkut31]

neden 2 Turk inglizce laf edersiniz, danisirsiniz ? neyse. node 16.19.1 versiyonu ile hata vermiyor. node 18.15.0 ile bende hata aldim .

[@storylineteam]

Run the loadtest command in a new terminal window outside of vscode

[@qureshiowais6951]

How Do we make rest API with cluster?

[@SoftwareDeveloperDiaries]

Same way you would make an ordinary Node.js API with Express, but in this case the entrypoint is primary.js, meaning it opens the port and serves the application.

[@qureshiowais6951]

@@SoftwareDeveloperDiaries please create few video with lates teach and practice thanks

[@mateuszfijak5293]

how can I use __dirname in typescript?

[@themaridv2000]

It comes by default

[@marwanFX483]

does this create race condition problem ?

[@SoftwareDeveloperDiaries]

Totally. It all depends on the use case and code that you've written.

[@cloudpg0788]

what does this even mean ???

[@internetexplorer7880]

Scenario: You go out for dinner in a new restaurant. 1st case: There's only one cook, so if the cook is busy making food for someone else you have to wait a long time for your order 2nd case: There are now multiple cooks, so if other people's food takes time, yours won't