specific error message is
General error: 1205 Lock wait timeout exceeded; try restarting transactionthe reason for this problem is that there is a process that has been occupying the lock and does not release it. How do you reproduce this problem? How to solve it?
How to debug Lock wait timeout exceeded on MySQL?
build a test table on which update does not submit, and another session will not be reproduced if you go to update.
show processlist finds the session that holds the lock, and just drop kill.
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