Design a Load Balancer for Web Servers

Functional Requirements:

• Distribute incoming HTTP/HTTPS requests across a pool of web servers to balance load.
• Support at least one basic load balancing algorithm (e.g., round-robin).
• Monitor the health of backend servers and avoid sending traffic to unhealthy servers.
• Allow dynamic addition and removal of backend servers from the pool.
• Provide an API or interface for managing server pool and viewing server health status.
• (Optional) Support session stickiness (session persistence) to direct a user's requests to the same server if needed.

Non-Functional Requirements:

• High availability: The load balancer should be resilient to failures and minimize downtime.
• Scalability: Should handle increasing traffic by scaling horizontally (adding more servers).
• Low latency: Introduce minimal delay when forwarding requests.
• Security: Should not introduce vulnerabilities; support HTTPS termination is a plus.
• Observability: Provide basic logging and metrics for monitoring traffic and server health.
• Simplicity: The system should be easy to configure and maintain.