A load balancing strategy or policy instructs the load balancer on where to send the next incoming request. There are many load balancing strategies available depending on the specific solution, however a few common ones are listed below:
Round Robin: The most simple load balancing method where each server takes a turn to receive a request.
Least Number of Connections: The load balancer will keep track of the number of connections a server has and send the next request to the server with the least connections. Note: Older, layer4 only load balancers tend not to support this as they typically run DSR (Direct Server Return) and don’t know how many connections are currently on the backend servers.
Weighted: Typically servers are allocated a percentage capability as one server could be twice as powerful as another. Weighted methods are useful if the load balancer does not know the real and actual performance of the server.