[alibaba/nacos]nacos获取mysql链接失败

部署环境： nacos版本：2.0.3 mysql版本：5.7.9

场景： 1、部署单机版nacos，没有启用mysql，nacos启动正常 2、nacos启用mysql，并提前导入nacos-mysql.sql脚本，启动nacos异常。

nacos配置如下：

nacos报错信息： org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:82) at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:371) at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:523) at com.alibaba.nacos.config.server.service.datasource.ExternalDataSourceServiceImpl$SelectMasterTask.run(ExternalDataSourceServiceImpl.java:212) at com.alibaba.nacos.config.server.service.datasource.ExternalDataSourceServiceImpl.reload(ExternalDataSourceServiceImpl.java:130) at com.alibaba.nacos.config.server.service.datasource.ExternalDataSourceServiceImpl.init(ExternalDataSourceServiceImpl.java:106) at com.alibaba.nacos.config.server.service.datasource.DynamicDataSource.getDataSource(DynamicDataSource.java:55) at com.alibaba.nacos.config.server.service.repository.extrnal.ExternalStoragePersistServiceImpl.init(ExternalStoragePersistServiceImpl.java:133) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363) at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307) at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:413) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1761) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1196) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:595) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:376) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1402) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1196) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:595) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:376) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1402) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1196) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:595) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:376) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1402) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:392) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1318) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1158) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:554) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1196) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:595) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:376) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1402) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1196) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:595) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:376) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1402) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.resolveBeanReference(ConfigurationClassEnhancer.java:394) at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:366) at com.alibaba.nacos.core.auth.AuthConfig$$EnhancerBySpringCGLIB$$a6523e58.authFilter() at com.alibaba.nacos.core.auth.AuthConfig.authFilterRegistration(AuthConfig.java:34) at com.alibaba.nacos.core.auth.AuthConfig$$EnhancerBySpringCGLIB$$a6523e58.CGLIB$authFilterRegistration$1() at com.alibaba.nacos.core.auth.AuthConfig$$EnhancerBySpringCGLIB$$a6523e58$$FastClassBySpringCGLIB$$a0fa8586.invoke() at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) at com.alibaba.nacos.core.auth.AuthConfig$$EnhancerBySpringCGLIB$$a6523e58.authFilterRegistration() at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1318) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1158) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:554) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:319) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:211) at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:202) at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addServletContextInitializerBeans(ServletContextInitializerBeans.java:96) at org.springframework.boot.web.servlet.ServletContextInitializerBeans.(ServletContextInitializerBeans.java:85) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getServletContextInitializerBeans(ServletWebServerApplicationContext.java:253) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.selfInitialize(ServletWebServerApplicationContext.java:227) at org.springframework.boot.web.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:53) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5128) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:843) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:105) at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.(TomcatWebServer.java:86) at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:416) at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:180) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:180) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:153) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391) at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204) at com.alibaba.nacos.Nacos.main(Nacos.java:35) Caused by: java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:906) at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:831) at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:456) at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246) at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:197) at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:354) at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:202) at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:473) at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:554) at com.zaxxer.hikari.pool.HikariPool.(HikariPool.java:115) at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158) at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116) at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79) ... 164 more Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:538) at com.mysql.cj.protocol.a.NativeProtocol.readServerCapabilities(NativeProtocol.java:490) at com.mysql.cj.protocol.a.NativeProtocol.beforeHandshake(NativeProtocol.java:377) at com.mysql.cj.protocol.a.NativeProtocol.connect(NativeProtocol.java:1340) at com.mysql.cj.NativeSession.connect(NativeSession.java:157) at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:850) ... 178 more Caused by: java.net.SocketTimeoutException: Read timed out at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) at java.net.SocketInputStream.read(SocketInputStream.java:171) at java.net.SocketInputStream.read(SocketInputStream.java:141) at com.mysql.cj.protocol.ReadAheadInputStream.fill(ReadAheadInputStream.java:107) at com.mysql.cj.protocol.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:150) at com.mysql.cj.protocol.ReadAheadInputStream.read(ReadAheadInputStream.java:180) at java.io.FilterInputStream.read(FilterInputStream.java:133) at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64) at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:63) at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:45) at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:532)

测试过程： 1、使用命令行工具可以链接mysql（5.7.9） 2、使用java的原生jdbc方式可以获取该mysql（5.7.9）的连接 3、nacos连接改成本地mysql（版本：5.5）地址，可以启动成功

这如何解决？