It is critical that the folder with the MySQL database files (by default, C:\ProgramData\MySQL\MySQL Server 5.1\data) and the Windows Temp folder (by default, C:\Windows\Temp) are excluded from virus scans and server backups. Both virus scan tools and backup tools can lock key files in these folders and interrupt the operation of the MySQL server and, by extension, MassTransit.
To backup the MySQL databases, it is recommended that you use the MySQL or other standard tools to automatically save the backup files to a folder or volume that can then be processed by your backup or archiving solution.
By default, MySQL uses TCP/IP port 3306 to accept client communications. It is recommended to restrict the traffic on this port by setting appropriate firewall rules. Usually, the only remote computers that should be allowed to access MySQL on the MassTransit server are those running the MassTransit Administrator (or those running the MassTransit Engine or MTWeb in rare configurations where MySQL is not running on the same server as MassTransit).