Fatal error: Uncaught PDOException: SQLSTATE[08004] [1040] Too many connections in /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Abstract.php:128
Stack trace:
#0 /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Abstract.php(128): PDO->__construct('mysql:host=127....', 'singerbd', 'SingerBD!TB@20', Array)
#1 /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Mysql.php(111): Zend_Db_Adapter_Pdo_Abstract->_connect()
#2 /var/www/html/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php(398): Zend_Db_Adapter_Pdo_Mysql->_connect()
#3 /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Abstract.php(460): Magento\Framework\DB\Adapter\Pdo\Mysql->_connect()
#4 /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SELECT `s_store...', Array)
#5 /var/www/html/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php(517): Zend_Db_Adapter_Pdo_Abstract->query('SELECT `s_store...', Array)
#6 /v in /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Abstract.php on line 144