What is load balancing in system design?

Load balancing is the process of distributing network traffic or computational workloads across multiple servers or resources. The primary goal is to optimize resource use, maximize throughput, minimize response time, and avoid overload of any single resource, thus ensuring high availability and reliability.

What are common load balancing algorithms?

Common load balancing algorithms include Round Robin, Least Connections, Least Response Time, and IP Hash. Each has its own advantages and is chosen based on the specific needs of the system, such as session persistence or server capacity.

System Design Interview

Load Balancing Strategies

Understand the core principles of load balancing, from basic algorithms like Round Robin to advanced techniques for building scalable and resilient systems.

Example: Round Robin Load Balancer in Python

A simple implementation of a Round Robin load balancer. This is a foundational concept in distributing traffic evenly across a set of servers.


                                class RoundRobinLoadBalancer:
                                    def __init__(self, servers):
                                        self.servers = servers
                                        self.index = 0
                                
                                    def get_server(self):
                                        # If no servers are available, return None
                                        if not self.servers:
                                            return None
                                
                                        # Get the server at the current index
                                        server = self.servers[self.index]
                                
                                        # Move to the next server for the next request
                                        self.index = (self.index + 1) % len(self.servers)
                                
                                        return server

Our AI Coach can walk you through more complex scenarios, like weighted round robin or implementing health checks for your servers to build a more robust load balancer.