My reason to use load balancer:
1. to split the load to multiple servers instead of single server
2. if one of the configured server is offline or temporary turn off the web service for maintenance or upgrade, there should be no interruption.
Current load balancer only supported fail over for frontend(load balancing servers itself).
Fail over for the backends(our servers) is not supported. If one of this servers is offline or the web service is not running. All website will be down. It should be like this.