Sometimes at nightly cron-jobs doing "mysqloptimize" one of the tables get marked "crashed" and automatic repair fails.
The last one is caused by related bug.
I tried to force the error by stressing the database with inserts/reads during mysqloptimize, but I was unable to get it crashed at the moment. But it happens sometimes at night (when the cron job runs).
The script which consists of
mysqlcheck -s -A
mysqloptimize -s -A
mysqlanalyze -s -A
is running for years without any problem. The problem first occured after update from MariaDB 5.5 to 10.0.19.
If this is relevant: all tables have Aria engine.
I still expect some racing condition - as a "user" I'm not familiar when a table is marked "crashed" - but there must be some condition when some lock, or gathering the lock interfears with this state after lock is removed.