Answer: ....
If one load balancer fails, the secondary picks up the failure and becomes active. They have a heartbeat link between them that monitors status. If all load balancers fail (or are accidentally misconfigured), servers down-stream are knocked offline until the problem is resolved, or you manually route around them.
Explanation:
Load balancing is a technique of distributing your requests over a network when your server is maxing out the CPU or disk or database IO rate. The objective of load balancing is optimizing resource use and minimizing response time, thereby avoiding overburden of any one of the resources.
The goal of failover is the ability to continue the work of a particular network component or the whole server, by another, should the first one fail. Failover allows you to perform maintenance of individual servers or nodes, without any interruption of your services.
It is important to note that load balancing and failover systems may not be the same, but they go hand in hand in helping you achieve high availability.
