Understanding Load Balancing

• Load balancing distributes incoming requests and traffic evenly across multiple servers.
• High availability, reliability, and performance are all achieved through load balancing.
• Load balancing avoids overloading single servers and downtime.
• A load balancer sits between the client and the server.
• The load balancer accepts incoming network and application traffic.
• Traffic is distributed across multiple backend servers using various algorithms.
• Load balancers reduce the load on individual servers.
• Overall application availability and responsiveness are both improved.
• Scalability and redundancy are fully utilized via load balancing at each system layer.
• Load balancers can be added between the user and the web server.
• Load balancers can be added between web servers and an internal platform layer, like application or cache servers.
• Load balancers can be added between the internal platform layer and the database.

Key Terminology and Concepts

• A load balancer is a device or software that distributes network traffic across multiple servers based on predefined rules or algorithms.
• Backend servers receive and process requests forwarded by the load balancer.
• Backend servers are also referred to as the server pool or server farm.
• A load balancing algorithm is the method used to determine how to distribute incoming traffic among the backend servers.
• Health checks are periodic tests performed by the load balancer to determine backend server availability and performance.
• Session persistence is a technique used to ensure that subsequent requests from the same client are directed to the same backend server, maintaining session state.
• SSL/TLS termination is decrypting SSL/TLS-encrypted traffic at the load balancer level, offloading the decryption burden from backend servers.
• SSL/TLS termination allows for centralized SSL/TLS management.

Load Balancer Processes

• Load balancers facilitate efficient utilization of computing resources and prevent overload by distributing incoming network traffic across multiple servers or resources.
• The load balancer receives a request from a client or user.
• The incoming request is evaluated to determine which server or resource should handle it.
• A predefined load-balancing algorithm is used, which takes into account factors such as server capacity, server response time, number of active connections, and geographic location.
• The incoming traffic is forwarded to the selected server or resource.
• The server or resource processes the request and sends a response back to the load balancer.
• The response from the server or resource is received and sent to the client or user who made the request.