You can specify the MySQL Connection Timeout value for your server. This option simply means that SQL DM for MySQL waits for this long to get a response from the server before it throws an error. This comes handy to avoid false positives when connection to some specific servers is slow. You can setup a larger timeout in such cases. If you have SSH Tunneling enabled to the MySQL then you can specify a SSH Tunnel Connection Timeout, and a SSH System Connection Timeout if System Metrics is enabled. The default value for all being 30 seconds.