33. What is load balancing and what are its advantages?

Load balancing is a technique for distributing network traffic across multiple servers to ensure optimal performance and availability of an application. A load balancer acts as a distribution point, directing client requests to the appropriate servers.

Advantages of load balancing:

1. Increased availability: Load balancing ensures application continuity even if one or more servers fail.
2. Better performance: Distributes traffic across multiple servers, reducing latency and increasing application response speed.
3. Scalability: Allows for easy addition of new servers to the pool to handle increasing loads.
4. Resource management: Load balancer can monitor server health and direct traffic only to those ready to handle requests, optimizing resource utilization.
5. Redundancy: Provides redundancy, increasing system reliability.

Example of load balancing configuration with Nginx:

http {
    upstream backend {
        server backend1.example.com;
        server backend2.example.com;
        server backend3.example.com;
    }

    server {
        listen 80;

        location / {
            proxy_pass http://backend;
        }
    }
}

Load balancing is a key component of modern application architectures, ensuring high availability, performance, and scalability.