key = fmt.Sprintf("%s:%s", service, instance.ServicePort.Name)
	instanceList = sd.instancesByPortName[key]
	sd.instancesByPortName[key] = append(instanceList, instance)
	eps := make([]*model.IstioEndpoint, 0, len(sd.instancesByPortName[key]))
	for _, port := range svc.Ports {
		key := fmt.Sprintf("%s:%s", service, port.Name)
		for _, i := range sd.instancesByPortName[key] {
			eps = append(eps, i.Endpoint)
		}
	}