Azure Classroom notes 04/Nov/2023

Distributing Traffic

Generally web servers when accessed create a load on cpu and memory for every request. As number of request increase one server will not be able to solve the problem/execute the request. On a broader note we have two options
- Horizontal scaling: Increase number of servers running the application
- Vertical Scaling: Increase the server resources such as CPU/Memory etc.
If the number of servers are many then we cant share all the ips to requster. To solve this we need to understand the concept of Proxy Servers

Load Balancers serve incoming traffic to a application and distribute it across servers
Load Balancers major functionality is around
- Distributing an application traffic so that the individual servers do not become overloaded
Types of Load Balancers (functionality)
- Layer 4 load balancer
- Layer 7 load balancer
Type of Load Balancers (creation)
- Hardware load balancer
- Software load balancer
- Virtual load balancer

Model overview
Each layer adds functionality
Now layer 4 loadbalancing can make load balancing decisions on the basis of
- ip address
- port
- protocol (TCP/UDP)
Layer 7 has knowledge of http in addition to layer 4

In cloud generally we have two types of load balancing
- internal load balancing
- internet facing/public load balancing
Terms:
- inbound: where the users will hit the load balancer
- outbound: where the load balancer needs to send the traffic
Azure Layer 4 Load Balancer
AWS Layer 4 Load Balancer
Mapping name to public address of Load Balancer is done in DNS zone

sudo apt update
sudo apt install apache2 -y
sudo apt install stress -y

<!DOCTYPE html>
<html>
<body style="background-color:powderblue;">
<h1>Welcome to Load Balancing</h1>
<p>This is for learning</p>
</body>
</html>