Outdated notes from zulip chat with marko;
Regarding package upgrades:
- upgrade from 10.2 or earlier should use innodb_fast_shutdown=0 (or better, SET GLOBAL innodb_max_purge_lag_wait=0, implemented in
MDEV-16952) to avoid hitting MDEV-15912
to implement in rpm/deb packaging scripts.
Update by marko:
MDEV-15912 was fixed by refusing to start up InnoDB in case the pre-10.3 format undo logs are not empty. It turns out that a clean shutdown (innodb_fast_shutdown=1) always guaranteed this; in some upgrade tests we had to jump through hoops to end up with nonempty undo logs and empty redo log. With MariaDB (thanks to MDEV-12289) there should never have been a need to issue a slow shutdown (innodb_fast_shutdown=0) before upgrading.