Hi, After tracing an issue that was preventing Monit correctly monitoring MariaDB, would a small update in the Monit manual be possible? I've found this while updating an old installation on which the following entry within a MySQL monitoring section worked perfectly:
if failed unixsocket /tmp/mysql.sock protocol mysql timeout 90 seconds then restart On a new installation with MariaDB version 10.11.3 on Raspbian 12 (based on Debian 12), Monit (version 5.33.0) kept reporting that MariaDB could not be started. Actually it was being started and then restarted generating a mess, because Monit could not connect to the unix socket. I found that disabling the unixsocket test enabled startup. But the cause is that MariaDB 10.4.3 and later have a unix_socket authentication plugin installed by default. This aims to check if the unix user connecting to the socket has been granted permission on the database resource they are trying to access. Whether Monit's connection would succeed if I created a MariaDB grant for the unix user Monit runs under I don't know. But I found it was simpler to disable this plugin by inserting unix_socket=OFF into the [maraidbd] section of /etc/mysql/my.cnf. Since Ubuntu 15.10 based on Debian 9 this unix_socket authentication has been a default so probably it's catching many people out. Could something about this be added to the manual page to alert people to this issue and work-around? https://mmonit.com/monit/documentation/monit.html#MYSQL Best regards, David.
