Conforme docs adicione este plug-in.
{
"type": "jdbc",
"driver": "com.mysql.jdbc.Driver",
"url": "jdbc:mysql://localhost:3306",
"username": "root",
"password": "mypassword",
"enabled": true
}
NOTA:Certifique-se de ter adicionado o jar do conector mysql em
<drill-directory>/jars/3rdparty 
