java.lang.IllegalStateException: failed to req API:/nacos/v1/ns/instance after all servers([192.168.2.16:8848]) tried: failed to req API:192.168.2.16:8848/nacos/v1/ns/instance. code:503 msg: server is DOWN now, please try again later!
at com.alibaba.nacos.client.naming.net.NamingProxy.reqAPI(NamingProxy.java:464) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.net.NamingProxy.reqAPI(NamingProxy.java:386) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.net.NamingProxy.registerService(NamingProxy.java:188) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.NacosNamingService.registerInstance(NacosNamingService.java:205) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.NacosNamingService.registerInstance(NacosNamingService.java:184) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:61) ~[spring-cloud-alibaba-nacos-discovery-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.register(AbstractAutoServiceRegistration.java:239) [spring-cloud-commons-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration.register(NacosAutoServiceRegistration.java:74) [spring-cloud-alibaba-nacos-discovery-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.start(AbstractAutoServiceRegistration.java:138) [spring-cloud-commons-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.bind(AbstractAutoServiceRegistration.java:101) [spring-cloud-commons-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:88) [spring-cloud-commons-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:47) [spring-cloud-commons-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.finishRefresh(ReactiveWebServerApplicationContext.java:118) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552) [spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
at com.atguigu.gulimail.gateway.GulimailGatewayApplication.main(GulimailGatewayApplication.java:20) [classes/:na]
解决方法：