Comment 2 for bug 1877713

Hi,
first of all a bit more what was happening than "abc" would have been nice.
Furthermore I'd urge you to upgrade as Ubuntu 19.10 has reached its EOL - please upgrade to the jsut released long term support 20.04 instead.

From your log:
mysqld will log errors to /var/log/mysql/error.log
mysqld is running as pid 29857
Error: Unable to shut down server with process id 29857

While I see in the error log:
[Warning] [MY-011068] [Server] The syntax 'validate password plugin' is deprecated and will be removed in a future release. Please use validate_password component instead.
this isn't the reason.
Your server usually shuts down in 1-2 second in that log which is fine.

Is this issue reproducible through a retry and even on any still supported release?
If so please provide more information (are the logs the same each time you trigger it) on the case.

Until that is provided there isn't enough in the logs to help you on this particular issue.