What happens before the Backend gets the Request

When we send a request to a backend most of us focus on the processing aspect of the request which is really just the last step.
There is so much more happening before a request is ready to be processed, most of this step happens in the Kernel. I break this into 6 steps, each step can theoretically be executed by a dedicated thread or process. Pretty much all backends, web servers, proxies, frameworks and even databases have to do all these steps and they all do choose to do it differently.
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0:00 Intro
3:50 What is a Request?
10:14 Step 1 - Accept
21:30 Step 2 - Read
29:30 Step 3 - Decrypt
34:00 Step 4 - Parse
40:36 Step 5 - Decode
43:14 Step 6 - Process
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Stay Awesome,
Hussein

[@hnasr]

Fundamentals of Operating Systems course oscourse.win

[@gneyhabub]

Finally, someone who's going beyond just explaining the API of the libraries! Don't stop man, you're making great content!

[@stormsake]

Second this. Many others only copy paste codes without knowing what happens behind the scenes.

[@AdekunleLawal]

So happy the algorithm brought this channel my way. Love the deep dives Hussein does 👏🏽

[@CodeShode]

Listen at 1.75 speed.

[@barebears289]

2.0x

[@rosshoyt2030]

1.0x

[@prerakhere]

Slow is smooth. Smooth is fast.

[@adhilk2775]

Thank you....

[@shyampramanik780]

This is GOLD !! Thanks Hussein for this amazing content.

[@shalabyx]

Amazing walkthrough 👏 I can’t imagine how this would look if you explain all this steps by using one use case! Anyway it’s just amazing 🌹

[@mauriciotamez4047]

There is so much knowledge here. ILYSM Hussein

[@ahmetyasarozer]

Perfect content, as usual. Thanks Hussein

[@pramod1591]

Your channel is a gold mine of information

[@prateek2159]

I missed your long videos. This one was a fab. Please keep making more such videos

[@iamansinghrajpoot]

I see lot of KZbinrs just scratch the surface and people comment you are the best. I like how thorough and detailed explanation you do.

[@hnasr]

Grab my new course Discovering Backend Bottlenecks: Unlocking Peak Performance performance.husseinnasser.com

[@sohansingh2022]

this helps me in my basics so much!

[@user-ok4fx3kl6f]

This is by far the best thing on internet! you're amazing!

[@cumbi-mongo]

Great content as always! Thanks a lot.

[@gustavodeoliveira8316]

you are a game changer. thanks for that man

[@abdullahclementabdulshekur6736]

I'm transitioning into backend from frontend and i wanted to learn and understand high and low level concept before building projects. and your courses have been very helpful. The netowking, backend and database engineering concepts.. have been really helpful to me. I do have a request though, a course on systems design would be great. Keep doing the good work..

[@hassanmunene5406]

Just last week we were doing an assignment on how to create a client-server architecture for a simple program That echo the requests from the client using sockets. We were using the c programming language and it was really interesting to learn how actually a server listens and accepts request and how it forks so as a to handle different clients while at the same time listening. This was what i needed to reinforce what i learnt and i felt really proud that i was actually understanding some concepts you were talking about. Im just a beginner in this field but i have so much fire and curiosity about the backend. I totally enjoyed this.!!❤

[@othmanalyusifey356]

that makes sense , can i know where u get this assinement from ? is it from a course or the collage

[@hassanmunene5406]

@@othmanalyusifey356 yeah it's from college. The unit is called Network programming

[@leoxvic4701]

​@@othmanalyusifey356most likely a network engineering assignment for unix networking programming

[@abc-ym4zs]

Where to learn this socket programming cab u recommend any good channel and where to learn about cpu and OS please bro I am facing difficulty

[@sonugupta147]

@@abc-ym4zs there is something as linux programmer's manual document. This contains all the system calls provided by the linux/unix OS which you can utilise to interact with the kernel i.e. ask for resources like memory, I/O, networking etc.

[@VincentDBlair]

Great material

[@arthurmiller9103]

This session is conceptually loaded and well explained. Thank you 🙏

[@timeisnow1100]

Great video

[@sourav_singh_diaries]

Crazy Good content 🔥

[@dannyhd8301]

Thank you .

[@aviadhaham]

you’re an asset to the world

[@renanoliveira0]

Thanks!

[@pieter5466]

To anyone watching this, I purchased and am partway thru 3 of Hussein's Udemy courses and they're great! Same quality walkthroughs but on a much wider variety topics. Only feedback would be: more evenly timed videos (some are 50mins..) and less digression off-current-topic.

[@karanyuvrajsingh4911]

Respect your cpu🫡

[@lakshaybhardwaj5923]

Thanks a lot for such amazing teachings. It has been really helpful to me.. You are the best!! However I have a question regarding this walkthrough.. How does this complete setup and 4 queues (SYN, ACCEPT, RECEIVE, SEND) behave when there are many concurrent HTTP requests vs when there are many web socket connections (or long lived connections like SSE ) ?

[@RichardHumulock]

Hussein is such a bad ass

[@giggleways]

Watching this I released more dopamine than watching a Netflix movie. ♥

[@fashionvella730]

Same here i am just consuming his content at night like i am watching NetFlix

[@RiversJ]

Great videos, i hopped from game dev doing lower levels where you didn't just need to understand the lower APIs but the hardware architecture to a point, in web dev you need to spend many times more effort to even just get a poorly explained abstraction of what the thing below you is doing much less a good lesson on the technology. Not everybody needs to be capable of lower lower coding, but I'm firmly of the opinion that understanding the layer below you is necessary to become truly good.

[@ericstoppel4634]

ily Hussein, keep it up please. This is like steroids to my backend carreer

[@adr420]

bro is in love with computer science :)

[@mhmdshaaban]

You are the best Hussein. I have a question as we keep accepting connections inside a single process it will open a new file descriptor where reading and writing happen there is always a limitation to the number of open files per process even though this number is configurable it is hard to determine what is the reasonable number.

[@meassurendra]

Dude , great content. But please use some pictures, diagrams to drive message through. It gets very difficult to sit through after a while

[@samirallahverdi4948]

Couldn't imagine these process in containerized environment :)

[@pajeetsingh]

You have to cover superconductor at room temp ongoing reports.

[@tekforge]

Hey Hussein, I really love the great content you share and how you share it! I'm also a senior software engineer who started a YT channel a few years ago and have 2 Udemy courses that I would love to dedicate more time to them to share more of what I learned in my career. Yet, it takes me a lot of effort to create content with the quality I'm satisfied with. When I see inspiring content creators like you, I wonder if you produce your content as a side hustle or if it's your full-time job. I see how you reflect and analyze things in order to understand them deeper and share lessons, but I notice also that the pressure in our full-time job as software engineers often doesn't give us enough time to reflect, analyze then share knowledge about what we learned. I appreciate your feedback regarding your own experience as an engineer and content creator!

[@AwadA-ey7pn]

I feel like a Staff level Software Engineer now 🎉🎉

[@GuilhermeGavioli]

Is there any book reference for the tcp / network part you mentioned on the video? To help understand tcp protocol better.

[@gauravaws20]

TCP Illustrated.

[@GuilhermeGavioli]

@@gauravaws20 By W. Richard Stevens?

[@gauravaws20]

@@GuilhermeGavioli yup

[@ryanseipp6944]

The io_uring part gets very interesting. Why call `accept` a bunch when you can have the kernel accept new connections automatically, and tell you about it. Why copy data on `recv` when you can have the kernel choose a buffer you've registered and tell you which one it chose. Even without these, that IO model is quite efficient when compared to epoll

[@samhadi7972]

It’s a game changer

[@manindersingh5577]

Hi sir can you tell me…if my computer is attacked with ransomware and photos and videos are encrypted…can the hackers use my photos and videos? Can they see them and import them?

[@sauraabh]

Can I create a blog out of this video? I'll give you the credits

[@florianvanbondoc3539]

The best bottleneck youtube channel :))))

[@mehdi-vl5nn]

what about non-block socket

[@bashardlaleh2110]

you're like the only arab guy I'm proud of 😁

[@usmanmaqsood5945]

Thank you for making things understandable for dumb developers like me :)

[@IshwarJangid]

Starts at @04:00

[@btm1]

its called abstraction, not closing your eyes

[@dannyhd8301]

just when i thought i am good backend lol

[@orhn]

"Kenekşın"

[@alisadeghi6410]

this video forcing me to write a simple backend framework to feel with my skin what is happening exactly

[@AlhassanRaad]

new

[@AlhassanRaad]

hello

[@nibblesnbits]

First!

[@gradientO]

17 year old account 💪

[@vijaydhanakodi5591]

This guy should speak with some energy.

[@giggleways]

I like the way he talks. it gives me time to think along the way.

[@RichardHumulock]

He does? lol.He speaks naturally.

[@arpmovies3609]

It's useless knowledge, cause you will never have to use it or have to know to become backed developers. 😅😅😅😅 He just read a blog about a topic and thought 🤔 to make a video of it.

[@RichardHumulock]

to be a good one you need to know it lol

[@arpmovies3609]

@@RichardHumulock you are absolutely wrong. To be a good backend developer you need to know backend topics (db, concurrency, caching etc..) not os related topics which is a waste of time. It might sound cool all of this but trust me you will never have to use it in your life as a backend developer