What is a load balancer and what advantages does it offer?

A load balancer is a device or software that distributes network traffic across multiple servers (a server pool), ensuring high availability and application performance.

Advantages:

• Increased availability: Redirects traffic from failed servers to operational ones, minimizing downtime.
• Enhanced performance: Distributes requests among multiple servers, preventing overload of a single server and reducing response time.
• Scalability: Allows dynamic addition or removal of servers in the pool, adapting to load changes.
• Improved user experience: Provides fast and stable interaction with the application.
• SSL/TLS termination: Can decrypt traffic, reducing load on backend servers.
• Session persistence (Sticky Sessions): Ensures requests from the same user are always directed to the same server, important for session-based applications.
• Health Checks: Regularly checks server health and automatically removes faulty servers from the pool.

Examples of load balancing algorithms:

• Round Robin
• Least Connections
• IP Hash
• Weighted Round Robin

Examples of load balancers:

• NGINX
• HAProxy
• AWS ELB (Elastic Load Balancing)
• Google Cloud Load Balancing
• Azure Load Balancer