Load balancing in Layer 4 vs Layer 7 with HAPROXY Examples

Load balancing is process of balancing incoming requests to multiple machines, processes or services. In this video we will explain two types of load balancers, layer 4 and layer 7.

Chapters
0:00 Intro
6:00 L4 Load balancer
9:10 L4 Load Balancer Pros and Cons
16:18 Example L4 Load Balancer with HAPROXY
22:30 L7 Load Balancer
27:00 L7 Pros and Cons
31:00 Example L7 Load Balancer with HAPROXY
37:00 Summary

Layer 4 (4/3)
Take content forwards it based on basic rules, it knows ip and port and perhaps latency of the target service.

Layer 4 - haproxy, NLB
Pros
- great for simple packet-level load balancing
- Fast and efficient doesn’t look at the data
- More secure as it cant really look at your packets. So if it was compromised no one can look
- Uses NAT
- One connection between client and server NATed
Cons
- Cant do smart load balancing based on the content, such as switch request based on requested media type
- Cant do microservices with this type
- Has to be sticky as it is a stateful protocol (all segments)

Layer 7 (Nginx , haproxy)

This type of proxy actually looks at the content and have more context, it knows you are visiting the /users resources so it may forward it to a different server. Essential and Great for microservices , it knows the content is video:image etc..

it can also cache.. we cant really do caching on layer 4 because we have no clue whats in the packets.

But expensive because it has to decrypt and look and compute

Layer 4 - haproxy, nlb
- great for simple packet-level load balancing
- fast and efficient doesn’t look at the data
- More secure as it cant really look at your packets. So id it was compromised no one can look
- Uses NAT
- One connection between client and server NATed
Layer 7 - examples nginx
- Smart routing based on the url (microservices) flexible
- Provide caching
- Expensive need to decrypt
- Secuirty, you have to share your certificate with the load balancers. Id compromised attacker has access to all your data.
- Proxy creates multiple connection (client to proxy/proxy to server)

Stay Awesome!
Hussein

[bahaaeldeen]

this playlist just keep getting better and better honestly it may be the greatest channel in the tech field

[anamulkabir]

"More we repeat more we learn!" that's the way to teach - thank you so much Nasser, you are the best!

[siddharthshukla]

dude, i simply love the way you articulate. It is like listening to a story. I tried to look up some other videos on this topic. But frankly speaking, the difference between Layer 4 and 7 was never explained so easily. Hats off to you Hussein

[amitbistk]

Great, I am a unix sysadmin and you helped me understand some old stuff making it easier. Those good old days!

[aarthydesikan]

Very well explained, thanks so much! Your way of explaining with an intent to capture audience attention but the same time not compromising the technical details is very nice.

[robertluong]

I randomly came here from your NAT video just for fun. I didn't expect to leave with a clear understanding of this. You're awesome.

[SunilRana-tmlm]

Hi Hussein!
I recently came across your channel and now I wish I had found this earlier. Thanks for the amazing informatic videos.

[SinghGaurav]

Hey man, thanks for the video, it was informative.
Your funny style made it even more interesting.

[iammjpops]

I dont know if I would have understood L4 and L7 R-Proxy better...
THANKS A LOT!

Bow to you!

[aniekutmfonekere]

the best channel ever with real-world application of tech

[fireystella]

Ur content is super great! And ur narration 😂 just when I’m losing my attention you say something funny and then I’m paying attention again 😆😆 many thanks!

[eraldkeshi]

HI Hussein ! I'm so happy to have found a channel with such a great content. I have noticed that besides the videos, your slides are also very clear and concise. It would be really helpful if you could also share a link to them ! Keep up the good work

[jeetendrashinde]

An excellent demostration of difference between the 2 Load balancers, good job Hussein !!

[xavierk]

A great explanation with a lot of energy. Love it!

[subhamprasad]

thank you, for your hard work. you are such an amazing person, sharing all this wonderful knowledge.

[rishabhjain]

Thanks for making our life easy and also for making your videos a lot more entertaining. :D

[wangsonny]

thanks for this great video, helps a lot for preparing system design interviews!

[davidlira]

this helped me have a better understanding of the difference between a Layer 4 Load Balancer and a Layer 7 Load Balancer.
Now I understand that an ingress is a Layer 7 Load Balancer

[arunsatyarth]

29:50 "I dont want the load balancer to look at my data." Sir, the fact that you dont have a million subscribers is a crime on humanity.

[ujemvi]

He killed me with the "pew pew pew" at the round robin demonstration