When working with Hibernate and MySQL, sometimes some exceptions will be thrown after sometime. The exception may seem like :java.sql.SQLException: Data source rejected establishment of connection, message from server: "Too many connections"This means there are too many active connections on the MySQL, you can useSHOW STATUS LIKE '%Threads_connected%';to check the active connections to MySQL. If you want to change the maximum connections allowed to MySQL. You can execute:set global max_connections = [num];You may forget to manually call session.close() methods iin your codes. If you have done ...