环境：ubuntu 18.04
mysql:5.7.30
nacos:1.1.4
nacos连接异常提示:
org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNested Exception: Cannot create PoolableConnectionFactory (Could not create connection to database server. Attempted reconnect 3 times. Giving up.) 33 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81)..... ............. ............ Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server. At tempted reconnect 3 times. Giving up.) 117 at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549) 118 at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388) 119 at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044) 120 at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) 121 at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) 122 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) 123 ... 82 more 124 Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconne ct 3 times. Giving up. 125 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method).... ............ Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 152 153 The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. 154 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 155 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) 156 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 157 at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 158 at com.mysql.jdbc.Util.handleNewInstance(Util.java:377) 159 at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1036) 160 at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:338) 161 at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2232) 162 at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2085) 163 ... 101 more 164 Caused by: java.net.ConnectException: Connection refused (Connection refused).... .......
网上查了各种方法都没用，最后还以是不是自己的mysql有问题，因为ubuntu安装mysql时是没有让输入密码的，所以root不用密码也能登录。
然后尝试创建新用户nacos，开放所有权限，还是没用。
最后给root添加，设置密码，居然解决了问题，用新建的nacos也可以用了
修改root用户的的密码如下：
这里是关键点，由于mysql5.7没有password字段，密码存储在authentication_string字段中，password()方法还能用
在mysql中执行下面语句修改密码
show databases； use mysql; update user set authentication_string=PASSWORD("yourpassword") where user=‘root‘; update user set plugin="mysql_native_password"; flush privileges; quit;