mysql老版本升级到(5.7.10)问题-performance_schema

老版本升级mysql版本时候会遇到如下问题：

Table 'performance_schema.session_variables' doesn't exist

这是因为MySQL 5.5新增一个存储引擎：命名PERFORMANCE_SCHEMA ,主要用于收集数据库服务器性能参数。MySQL用户是不能创建存储引擎为PERFORMANCE_SCHEMA的表

performance_schema提供以下功能： 
1.提供进程等待的详细信息，包括锁、互斥变量、文件信息； 
2.保存历史的事件汇总信息，为提供MySQL服务器性能做出详细的判断； 
3.对于新增和删除监控事件点都非常容易，并可以随意改变mysql服务器的监控周期

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'performance_schema.session_variables' doesn't exist
at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.Util.getInstance(Util.java:384)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2832)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2781)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1569)
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:4218)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3613)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2554)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2321)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.GeneratedConstructorAccessor4.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:208)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)
2016.02.05 13:38:34 org.jivesoftware.util.log.util.CommonsLogFactory - Prototype

解决方法

mysql_upgrade -u root -p --force

查看是否成功

mysql> SHOW VARIABLES LIKE 'performance_schema';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| performance_schema | ON    |
+--------------------+-------+
1 row in set (0.00 sec)