private Function<String, Publisher<ServiceInstance>> loadInstancesFromNacos() {
		return serviceId -> {
			try {
				return Mono.justOrEmpty(serviceDiscovery.getInstances(serviceId))
						.flatMapMany(instances -> {
							ServiceCache.setInstances(serviceId, instances);
							return Flux.fromIterable(instances);
						});
			}
			catch (NacosException e) {
				log.error("get service instance[{}] from nacos error!", serviceId, e);
				return failureToleranceEnabled
						? Flux.fromIterable(ServiceCache.getInstances(serviceId))
						: Flux.empty();
			}
		};
	}
@author <a href="mailto:echooy.mxq@gmail.com">echooymxq</a>
@author freeman
spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/discovery/reactive/NacosReactiveDiscoveryClient.java