Fatal error: Uncaught PDOException: SQLSTATE[08004] [1040] Too many connections in /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:43 Stack trace: #0 /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php(43): PDO->__construct('mysql:host=loca...', 'root', 'bk.zhuxin[2Sgrw...', Array) #1 /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php(44): Doctrine\DBAL\Driver\PDOConnection->__construct('mysql:host=loca...', 'root', 'bk.zhuxin[2Sgrw...', Array) #2 /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(360): Doctrine\DBAL\Driver\PDOMySql\Driver->connect(Array, 'root', 'bk.zhuxin[2Sgrw...', Array) #3 /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(833): Doctrine\DBAL\Connection->connect() #4 /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(510): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM b...', Array, Array) #5 /var/www/edusoho/vendor/codeages/biz-framework/src in /var/www/edusoho/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php on line 115