Load balancing in Layer 4 vs Layer 7 with HAPROXY Examples

💻 More software engineering videos https://www.youtube.com/playlist?list=PLQnljOFTspQXOkIpdwjsMlVqkIffdqZ2K 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 -