MySQL upgrade reference
Best Practices for MySQL Upgrade - Technical Translation - Open Source China Community
https://www.oschina.net/translate/mysql-upgrade-best-practices?lang=chs&page=2#
MySQL 5.6 upgrade to MySQL 5.7--------the best practice for version upgrade-sea-51CTO blog
http://blog.51cto.com/lisea/1941616
Record the operation and maintenance practice of a MySQL upgrade – operation and maintenance school
http://www.yunweipai.com/archives/24315.html