I have a number of sites that are still using CMSB 2.65, and I am being pushed to upgrade to wither MySQL 5.7 or Maria DB10.x.
Are there going to be any issues with these sites functioning with the DB upgrade, and which would you recommend?
Either MySQL or MariaDB would work just fine. I just checked and we run Maria DB on our live site and MySQL on our development server. But typically MariaDB is a drop-in replacement. You can see more details here: https://mariadb.com/kb/en/library/mariadb-vs-mysql-compatibility/ And I don't have a strong preference for either, but we code for MySQL so that our code works everywhere.
About the CMSB version, Mysql 5.7 was released a few months after CMSB 2.65, so I'd recommend upgrading to the latest version of CMSB. You'll need it for PHP 7 compatibility as well. I wrote a post on how to charge your clients for upgrades like this here: https://www.interactivetools.com/forum/forum-posts.php?postNum=2242892
Hope that helps! Let me know any other questions.
Dave Edis - Senior Developer