after receiving email from chkservd with mysql service stopped and recovered I investigated and
checked /var/log/cron and /var/lib/mysql/[host].err file, ant noticed that at the same time that mysqluserstore script is run sql server is restarting, every two hours, in the script comments we have:
# We used to do this during restartsrv however that turned out to be
# a problem because check_mysql_password_works_or_reset can restart
# mysql if the password is wrong.
also in mysql err log file I encounter:
2019-05-27T21:42:04.329471Z 2 [Note] Access denied for user 'UNKNOWN_MYSQL_USER'@'localhost' (using password: NO)
so it seems to be related to the above comment
checked /var/log/cron and /var/lib/mysql/[host].err file, ant noticed that at the same time that mysqluserstore script is run sql server is restarting, every two hours, in the script comments we have:
# We used to do this during restartsrv however that turned out to be
# a problem because check_mysql_password_works_or_reset can restart
# mysql if the password is wrong.
also in mysql err log file I encounter:
2019-05-27T21:42:04.329471Z 2 [Note] Access denied for user 'UNKNOWN_MYSQL_USER'@'localhost' (using password: NO)
so it seems to be related to the above comment