nacos使用mysql8作为存储媒介时报Caused by: com.mysql.cj.exceptions.CJException: Public Key Retrieval is not all

nacos2使用外部搭建的mysql8服务作为存储媒介，刚搭建完mysql8发现nacos连接mysql8没有任何问题，但是后面突然报了类似下面的异常信息

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.<init>(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.<init>(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) ... 172 more Caused by: com.mysql.cj.exceptions.CJException: Public Key Retrieval is not allowed 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.createException(ExceptionFactory.java:124) at com.mysql.cj.protocol.a.authentication.CachingSha2PasswordPlugin.nextAuthenticationStep(CachingSha2PasswordPlugin.java:151) at com.mysql.cj.protocol.a.authentication.CachingSha2PasswordPlugin.nextAuthenticationStep(CachingSha2PasswordPlugin.java:49) at com.mysql.cj.protocol.a.NativeAuthenticationProvider.proceedHandshakeWithPluggableAuthentication(NativeAuthenticationProvider.java:438) at com.mysql.cj.protocol.a.NativeAuthenticationProvider.connect(NativeAuthenticationProvider.java:171) at com.mysql.cj.protocol.a.NativeProtocol.connect(NativeProtocol.java:1342) at com.mysql.cj.NativeSession.connect(NativeSession.java:157) at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:850) ... 186 more Caused by: com.mysql.cj.exceptions.UnableToConnectException: Public Key Retrieval is not allowed 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:85) at com.mysql.cj.protocol.a.authentication.CachingSha2PasswordPlugin.nextAuthenticationStep(CachingSha2PasswordPlugin.java:128)

前几次还报了下面的错误日志：

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.<init>(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.<init>(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) ... 172 more Caused by: com.mysql.cj.exceptions.CJException: null, message from server: "Host '172.18.0.4' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'" 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.createException(ExceptionFactory.java:129) at com.mysql.cj.protocol.a.NativeProtocol.rejectProtocol(NativeProtocol.java:365) at com.mysql.cj.protocol.a.NativeProtocol.readServerCapabilities(NativeProtocol.java:494) 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) ... 186 more

最下面爆出的日志都是

Caused by: com.alibaba.nacos.api.exception.NacosException: Nacos Server did not start because dumpservice bean construction failure : No DataSource set at com.alibaba.nacos.config.server.service.dump.DumpService.dumpOperate(DumpService.java:204) at com.alibaba.nacos.config.server.service.dump.ExternalDumpService.init(ExternalDumpService.java:52) 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) ... 53 common frames omitted Caused by: java.lang.IllegalStateException: No DataSource set

所以如果不向上翻日志的话可能找不到解决问题的方法，最初几次nacos启动失败爆出的错误信息也不能明确问题所在，只能告诉我们nacos连接MySQL错误次数过多，最后一次启动失败日志则给出了明确的解决方向，具体方法为在数据库连接url上增加allowPublicKeyRetrieval=true配置

如果使用nacos-server docker部署的话可以增加下面的配置

MYSQL_SERVICE_DB_PARAM: characterEncoding=utf8&connectTimeout=2000&allowPublicKeyRetrieval=true&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC

该参数具体解析参照mysql官网说明：https://mysqlconnector.net/connection-options/