Load balancers use different algorithms to distribute incoming network traffic across multiple servers or resources in order to optimize performance, improve availability, and ensure efficient utilization of resources. Here are some common types of load balancing algorithms:
Round Robin (RR): This algorithm evenly distributes incoming requests across the available servers in a sequential manner. Each request is forwarded to the next server in a cyclic order.
Least Connection (LC): This algorithm directs new requests to the server with the fewest active connections. It balances the load based on the current connection count, aiming to distribute requests evenly across servers.
Weighted Round Robin (WRR): In this algorithm, each server is assigned a weight that represents its capacity or capability to handle traffic. Requests are distributed among servers based on their respective weights. Servers with higher weights receive a larger proportion of the traffic.
Least Response Time (LRT): This algorithm routes requests to the server with the lowest average response time. It dynamically measures the response time of each server and directs traffic to the server with the fastest response.
IP Hash: This algorithm calculates a hash value based on the client's source IP address and uses the value to determine which server should handle the request. It ensures that requests from the same client IP are consistently directed to the same server, which can be useful for session persistence.
Least Bandwidth: This algorithm distributes requests to servers based on their current network utilization or available bandwidth. It directs traffic to the server with the least amount of bandwidth usage to optimize network resources.
Random: The random algorithm selects a server randomly from the available pool for each request. While it may not ensure perfect load balancing, it can provide a simple and effective distribution mechanism.
These are just a few examples of load balancing algorithms. Different load balancers and application delivery controllers (ADCs) may offer additional algorithms or variations of these algorithms to suit specific needs and requirements. The choice of algorithm depends on factors such as the characteristics of the workload, server capacities, traffic patterns, and desired performance objectives