Load balancing is the process by which inbound internet protocol (IP) traffic can be distributed across multiple servers. Load balancing enhances the performance of the servers, leads to their optimal utilization and ensures that no single server is overwhelmed. Load balancing is particularly important for busy networks, where it is difficult to predict the number of requests that will be issued to a server.

Typically, two or more web serves are employed in a load balancing scheme. In case one of the servers begins to get overloaded, the requests are forwarded to another server. Load balancing brings down the service time by allowing multiple servers to handle the requests. This service time is reduced by using a load balancer to identify which server has the appropriate availability to receive the traffic.

The process, very generally, is straightforward. A webpage request is sent to the load balancer, which forwards the request to one of the servers. That server responds back to the load balancer, which in turn sends the request on to the end user.

Load balancing allows the service to continue even in the face of server down time due to server failure or server maintenance. If you are load balancing across several servers and one of the servers fails, your service will still be available to your users, as the traffic will be diverted to the other servers in your server farm. In Global Server Load Balancing (GSLB) the load is distributed to geographically scattered server farms, depending on their load, health or proximity.

There are several types of load balancing methods. If the servers are similar in hardware specifications, the Perceptive method (which predicts the server based on historical and current data) and the Fastest Response Time methods can be the best to use. On the other hand, if the hardware specifications are different, the Weighted Round Robin method, which assigns requests to servers in turn according their weights, may be a better solution because it can assign more requests to the server that can handle a greater volume.