Load balancer includes virtual servers, server pools, and health checks monitors.
A load balancer is connected to a Tier-1 logical router. The load balancer hosts single or multiple virtual servers. A virtual server is an abstract of an application service, represented by a unique combination of IP, port, and protocol. The virtual server is associated to single to multiple server pools. A server pool consists of a group of servers. The server pools include individual server pool members.
To test whether each server is correctly running the application, you can add health check monitors that check the health status of a server.