Can you explain the role and principles of operation of the load balancing mechanism between servers?

Load balancing mechanism between servers is designed to evenly distribute incoming requests or tasks to improve system performance, fault tolerance, and scalability.

Main principles of operation:

• Request distribution: The load balancer accepts incoming requests and redirects them to one of the available servers.

• Load balancing algorithms: There are several algorithms, for example:

  • Round Robin — requests are sent sequentially to each server.
  • Least Connections — requests are directed to the server with the fewest active connections.
  • IP Hash — server selection based on the hash of the client's IP.

• Server health checks: The load balancer periodically checks if servers are available and excludes unavailable ones from the pool.

• Sessions and state preservation: For some applications, it is important that requests from the same client are handled by the same server (sticky sessions).

Example: In a web application, a load balancer (such as Nginx or HAProxy) accepts HTTP requests and distributes them among multiple application instances to prevent overload of a single server and ensure uninterrupted operation in case of node failures.