Warning: mysqli::__construct(): (HY000/2002): Connection refused in /var/www/html/system/database/mysqli.php on line 6

Fatal error: Uncaught ErrorException: Error: Could not make a database link (2002) Connection refused in /var/www/html/system/database/mysqli.php:9 Stack trace: #0 /var/www/html/system/nitro/core/nitro_db.php(24): DBMySQLi->__construct('172.16.10.11', 'open', 'phbfeTHm6zCJw36...', 'opencart4') #1 /var/www/html/system/nitro/core/nitro_db.php(8): NitroDb->__construct() #2 /var/www/html/system/nitro/core/core.php(362): NitroDb::getInstance() #3 /var/www/html/system/nitro/core/core.php(381): getOpenCartSetting('config_maintena...') #4 /var/www/html/system/nitro/core/core.php(390): inMaintenanceMode() #5 /var/www/html/system/nitro/core/top.php(414): isNitroEnabled() #6 /var/www/html/system/nitro/core/top.php(424): open_nitro() #7 /var/www/html/system/nitro/core/core.php(4): require_once('/var/www/html/s...') #8 /var/www/html/vqmod/vqcache/vq2-system_startup.php(78): require_once('/var/www/html/s...') #9 /var/www/html/index.php(21): require_once('/var/www/html/v...') #10 {main} thrown in /var/www/html/system/database/mysqli.php on line 9