UNABLE TO CONNECT TO DATABSE!

Fatal error: Uncaught RuntimeException: PDOException: SQLSTATE[08006] [7] connection to server at "polymart-dev-new.cmorpn4dsujc.us-east-1.rds.amazonaws.com" (172.31.64.47), port 5432 failed: FATAL: sorry, too many clients already connection to server at "polymart-dev-new.cmorpn4dsujc.us-east-1.rds.amazonaws.com" (172.31.64.47), port 5432 failed: FATAL: sorry, too many clients already in /var/www/html/polymart/utils/Doco.php:136 Stack trace: #0 /var/www/html/polymart/utils/Doco.php(136): PDO->__construct() #1 /var/www/html/polymart/utils/Doco.php(351): Doco\newConnection() #2 /var/www/html/polymart/utils/Doco.php(542): Doco\makeFetch() #3 /var/www/html/polymart/utils/Doco.php(465): Doco\fetch() #4 /var/www/html/polymart/web/pages/profile/template.php(22): Doco\fetchObject() #5 /var/www/html/polymart/web/pages/profile/index.php(6): include_once('...') #6 {main} in /var/www/html/polymart/utils/Doco.php:170 Stack trace: #0 /var/www/html/polymart/utils/Doco.php(351): Doco\newConnection() #1 /var/www/html/polymart/utils/Doco.php(542): Doco\makeFetch() #2 /var/www/html/polymart/utils/Doco.php(465): Doco\fetch() #3 /var/www/html/polymart/web/pages/profile/template.php(22): Doco\fetchObject() #4 /var/www/html/polymart/web/pages/profile/index.php(6): include_once('...') #5 {main} thrown in /var/www/html/polymart/utils/Doco.php on line 170