What Is Load Balancing?

Load balancing is the act of distributing incoming network traffic across backend servers to balance the amount of traffic across a pool of servers. It allows applications to perform better by sending requests to multiple servers, decreasing the burden of managing and maintaining network sessions.

Load balancing allows applications to be readily available to users, boosting performance while also allowing for an extra layer of security for the network.

Read more: Information Technology (IT) Terms: A to Z Glossary

How does load balancing work

Load balancing relies on dedicated servers used to distribute incoming traffic. The balancer sends requests to servers with the least amount of traffic, requests, or volume of data being distributed.

Sending traffic in different directions allows servers to reliably and efficiently respond to requests from users. It also gives companies flexible options to adjust server use depending on the level of demand for requests from customers trying to access the information.

Types of load balancing

You can use different algorithms to help you operate load balancing on a network depending on your needs. The list below shows some common algorithms you can utilize.

• Round robin. The load balancer delivers requests equally throughout the group of servers. The load balancer sends traffic to servers based on a preset order so each server takes on a equal amount of traffic. This option works best when you expect clients to make requests that are similar, so that it doesn’t overwhelm one server while underutilizing another.

• Least connections. The load balancer sends traffic to the server with the fewest current connections. Use this option if you’re not sure how long a client’s connection with the server will last, prioritizing servers with open connections while other servers may still be handling client traffic.

• IP hash. The load balancer uses a client’s IP address to determine where to send traffic. This version of load balancing works if you have an organization that deals with multiple international clients

• Random. A server at random handles the requests of clients based on an algorithm. You can also choose the random "power of two choices" algorithm in which the load balancer picks two servers randomly and then chooses the best to handle the client’s traffic.

Related terms

• Computer networking

• Server maintenance

• IT support

Learn more about load balancing

If you’re interested in learning more about load balancing, try earning the Google IT Support Professional Certificate on Coursera. The certificate program teaches you the skills you need for an IT support position, including load balancing, troubleshooting computer issues, and day-to-day IT support tasks.