Re: Upgrade Problems

[Herrick Peterson]

Hey Miguel,

"Unusable" could mean a multiple things, so more detail would help. I am agree with Edward here. In the meantime, a few common things that can be related to the issue of MySQL upgrade:

1) Would not start- usually a data dictionary upgrade that got interrupted (crash, full disk, OOM), or a my.cnf setting that iss no longer valid in the new version.
2) Jumped multiple versions or did not shut down cleanly - InnoDB can struggle to recover redo logs on startup.
3) Server is fine but app can not connect - check if you are using mysql_native_password [newer MySQL disables it by default, breaking old connectors even though the DB itself is healthy].

Also I want to ask did you run the upgrade checker first? util.checkForServerUpgrade() in MySQL Shell (or mysql_upgrade on older setups) usually catches this stuff in advance.

If you can share your OS, the version you upgraded from/to, and the actual error log text, that will narrow it down fast.

I am looking forward to your update.

Herrick
DevOps Engineer @accuweb.cloud