假设原来是mysql 5.6.19社区版，现在要升级到percona server 5.6.30。
对于大的数据库来说，采用mysqldump方式进行迁移太花费时间了，可采用新安装加载原来数据库的方式大大节约升级时间。
对于mysql升级来说，一个主要的步骤就是升级后权限的同步更新以及数据表的校验。
假设原来为/usr/local/mysql-> mysql-5.6.19-linux-glibc2.5-x86_64，数据库在data目录下。
0、停止现有实例，/usr/local/mysql/bin/mysqladmin -u -p shutdown
1、首先，删除原来的符号链接rm rf /usr/local/mysql；
2、解压Percona-Server-5.6.30-rel76.3-Linux.x86_64.ssl101.tar.gz到当前目录；
3、创建新的符号链接ln -s Percona-Server-5.6.30-rel76.3-Linux.x86_64.ssl101 mysql
4、更改my.cnf，去掉datadir、basedir注释，如下：
basedir = /usr/local/mysql #指向最新的mysql实例
datadir = /usr/local/mysql-5.6.19-linux-glibc2.5-x86_64/data 指向原来的mysql数据库目录
其他配置可以保持不变。。。
5、使用新的安装包创建启动mysql实例：/usr/local/mysql/bin/mysqld_safe --user=mysql &
6、执行mysql_upgrade
[root@localhost bin]# ./mysql_upgrade -uroot -p
Warning: Using a password on the command line interface can be insecure.
Looking for 'mysql' as: ./mysql
Looking for 'mysqlcheck' as: ./mysqlcheck
Running 'mysqlcheck with default connection arguments
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck with default connection arguments
Warning: Using a password on the command line interface can be insecure.
mysql.columns_priv OK
mysql.db OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.innodb_index_stats OK
mysql.innodb_table_stats OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.servers OK
mysql.slave_master_info OK
mysql.slave_relay_log_info OK
mysql.slave_worker_info OK
mysql.slow_log OK
mysql.tables_priv OK
mysql.time_zone OK
mysql.time_zone_leap_second OK
mysql.time_zone_name OK
mysql.time_zone_transition OK
mysql.time_zone_transition_type OK
mysql.user OK
Running 'mysql_fix_privilege_tables'...
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck with default connection arguments
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck with default connection arguments
Warning: Using a password on the command line interface can be insecure.
mig_db.mig_tab OK
mig_db.mig_tab2 OK
OK
7、重启mysql实例。
8、客户端验证，可发现所有数据和存储过程均正常。