Originally reported as http://bugs.mysql.com/bug.php?id=65809
Since systemd tries to start services parallel, it's not easy to ensure that mysql daemon is started before another service, which requires it. Currently, we have to use an arbitrary script, that checks if the daemon is ready.
However, systemd has a feature to notify daemon about a service status, which would help in this scenario a lot and packagers wouldn't need any additional scripts to test daemon status. MySQL daemon can simple send a message to systemd daemon, that startup actions have been done successfully and we are ready to accept connections.
Using this feature is really straightforward and doesn't make any issues if a user uses alternative init system. To be concrete, only one function call and some configuration checking is needed.
Please, consider adopting the following patch attached.