1.背景，直接升级操作系统从centos-》国产化操作系统，mysql也升级到5.7.44
2，报错
java
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_144]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_144]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_144]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.Util.getInstance(Util.java:408) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2163) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2088) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_144]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_144]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_144]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:718) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:650) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:468) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) ~[tomcat-jdbc-8.5.6.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) ~[tomcat-jdbc-8.5.6.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.tool.schema.internal.TargetDatabaseImpl.prepare(TargetDatabaseImpl.java:38) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
... 28 common frames omitted
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 0 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_144]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_144]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_144]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:164) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4898) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1659) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2104) ~[mysql-connector-java-5.1.40.jar:5.1.40]
... 50 common frames omitted
Caused by: javax.net.ssl.SSLException: Received fatal alert: internal_error
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208) ~[na:1.8.0_144]
at sun.security.ssl.Alerts.getSSLException(Alerts.java:154) ~[na:1.8.0_144]
at sun.security.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:2033) ~[na:1.8.0_144]
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1135) ~[na:1.8.0_144]
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385) ~[na:1.8.0_144]
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413) ~[na:1.8.0_144]
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397) ~[na:1.8.0_144]
at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:149) ~[mysql-connector-java-5.1.40.jar:5.1.40]这里主要是最下面的Caused by: javax.net.ssl.SSLException: Received fatal alert: internal_error
3，分析原因
在MySQL5.7.41及之前的版本，安全性较低，存在任何用户都可以连接上的 test 库，所以官方在5.7.43版本加大了对隐私的保护。并且采用了默认 useSSL = true值防止对数据库的随意修改，导致项目启动时连接不上数据库
4，连接串添加&useSSL=false