// AddInstanceListener makes the Load Balancer know of the newly added service instance.
// It adds the service instances to the routers it knew.
// TODO: It assumes the new instance is newly created: which means no other router had it before.
func (lb *LoadBalancer) AddInstanceListener(event controller.Event) {
if event.Type() != controller.AddInstanceEventType {
panic("")
}
e := event.(*controller.AddInstanceEvent)
for _, r := range lb.Controller.Routers {
instance := e.Instance
port, ok := ServicePortMap[instance.Service]
if !ok {
log.Println("Unknown port for service:", instance.Service)
continue
}
err := r.AddService(instance.Service, port, router.NewRoundRobinPolicy())
if err != nil {
log.Println(err)
}
err = r.AddServiceInstance(instance.Service, instance)
if err != nil {
log.Println(err)
}
}
}
// AddRouterListener makes the Load Balancer know of the newly added router.
// It adds known service instances to the router and set service policy as round robin.
// TODO: It assumes the new router is newly created: which means it has no services.
func (lb *LoadBalancer) AddRouterListener(event controller.Event) {
if event.Type() != controller.AddRouterEventType {
panic("")
}
e := event.(*controller.AddRouterEvent)
r := lb.Controller.Routers[e.Id]
for service, instances := range lb.Controller.ServiceInstances {
port, ok := ServicePortMap[service]
if !ok {
log.Println("Unknown port for service:", service)
continue
}
err := r.AddService(service, port, router.NewRoundRobinPolicy())
if err != nil {
log.Println(err)
}
for _, instance := range instances {
err := r.AddServiceInstance(service, instance)
if err != nil {
log.Println(err)
}
}
}
}
func init() {
rIdPolicyMap = make(map[string]router.Policy)
rIdPolicyMap["rr"] = router.NewRoundRobinPolicy()
rIdPolicyMap["rand"] = router.NewRandomSelectPolicy()
}