It is MariaDB JDBC error so probably database which you are trying to connect can not handle this amount of concurrent connections (alternatively if you are not connecting to MariaDB databse, MariaDB is used also for hive metastore in your case mariadb://livongo-db.chkweekm4xjq.us-east-1.rds.amazonaws.com:3306 so if is that the case (but I don't think so) please report it to AWS)