文章目录
背景
手头有多台云服务器，有阿里云也有腾讯云，现在想做一个微服务软件，把这些服务器利用起来。先搭了个Nacos服务器试试水，使用浏览器能访问Nacos的控制面板，但是代码里却连接不上。
软件版本
Nacos: Nacos-2.1.1
Spring Cloud Alibaba: 2.2.9.RELEASE
Spring Boot: 2.3.12.RELEASE
Spring Cloud: Hoxton.SR12
问题情景
在一台服务器配置了Nacos，并且开通的对应端口的防火墙，可以使用浏览器进入管理面板。在IDEA里面配置spring.cloud.nacos.server-addr后，启动服务失败，报错信息如下：
org.springframework.context.ApplicationContextException: Failed to start bean 'webServerStartStop'; nested exception is java.lang.reflect.UndeclaredThrowableExceptionat org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:185) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:53) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:360) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:158) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:122) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:895) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at xyz.riyun.testnacos.order.OrderApplication.main(OrderApplication.java:18) [classes/:na]Caused by: java.lang.reflect.UndeclaredThrowableException: nullat org.springframework.util.ReflectionUtils.rethrowRuntimeException(ReflectionUtils.java:147) ~[spring-core-5.2.15.RELEASE.jar:5.2.15.RELEASE]at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:82) ~[spring-cloud-starter-alibaba-nacos-discovery-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.register(AbstractAutoServiceRegistration.java:239) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]at com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration.register(NacosAutoServiceRegistration.java:78) ~[spring-cloud-starter-alibaba-nacos-discovery-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.start(AbstractAutoServiceRegistration.java:138) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.bind(AbstractAutoServiceRegistration.java:101) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:88) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:47) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]at org.springframework.boot.web.servlet.context.WebServerStartStopLifecycle.start(WebServerStartStopLifecycle.java:46) ~[spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:182) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]... 14 common frames omittedCaused by: com.alibaba.nacos.api.exception.NacosException: Request nacos server failed: at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.requestToServer(NamingGrpcClientProxy.java:288) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.doRegisterService(NamingGrpcClientProxy.java:128) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.registerService(NamingGrpcClientProxy.java:114) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.client.naming.remote.NamingClientProxyDelegate.registerService(NamingClientProxyDelegate.java:94) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.client.naming.NacosNamingService.registerInstance(NacosNamingService.java:145) ~[nacos-client-2.1.0.jar:na]at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:74) ~[spring-cloud-starter-alibaba-nacos-discovery-2.2.9.RELEASE.jar:2.2.9.RELEASE]... 27 common frames omittedCaused by: com.alibaba.nacos.api.exception.NacosException: Client not connected, current status:STARTINGat com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:651) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:631) ~[nacos-client-2.1.0.jar:na]at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.requestToServer(NamingGrpcClientProxy.java:278) ~[nacos-client-2.1.0.jar:na]... 32 common frames omitted解决方案
多开两个端口的防火墙，一个是Nacos暴露的端口偏移1000，另一个偏移1001.
e.g. 当前Nacos的端口是8848，需要额外放开9848和9849端口的防火墙。
产生原因
Nacos2.0之后会多用到两个端口用于gRPC调用。
上面举例的两个端口中，9848端口是客户端gRPC请求服务端端口，用于客户端向服务端发起连接和请求；9849端口是服务端gRPC请求服务端端口，用于服务间同步等。
来源地址：https://blog.csdn.net/weixin_45413689/article/details/128586366
