MYSQL 5.7 Issue

[Jonathan Grimshaw]

Hope someone can help us.

We have an old 5.6 Mysql Server, that is taking a small step to mysql 5.7. At the sametime it was updated to utf8mb4.

We imported our data into the database and things seemed to work pretty well. After about an hour or so of testing, our web app connected to the DB started to see performance issues. We connected to the DB to see what was going on and one of the tables had got massively messed up. By messed up, it disappeared completely, however mysql believed it still existed and wouldnt allow a drop, create or update of the database.

On further digging we feel its related to something in the innodb config. Its using files per table and buffer is set to about 75% of the ram, but no matter what we did we were unable to rectify the issue.

We have now rolled back to previous data import, re-importing data again to hopefully see what caused this issue to start.

I'm hopefully asking if anyone has seen anything like this before or has any ideas how we may resolve it, in advance of our data migration completing within the next couple of hours.

thanks in advance