Warning: mysqli_connect(): php_network_getaddresses: getaddrinfo for rdb failed: Temporary failure in name resolution in /var/www/html/includes/config_db.php on line 17

Fatal error: Uncaught mysqli_sql_exception: php_network_getaddresses: getaddrinfo for rdb failed: Temporary failure in name resolution in /var/www/html/includes/config_db.php:17 Stack trace: #0 /var/www/html/includes/config_db.php(17): mysqli_connect('rdb', 'php-skripte', Object(SensitiveParameterValue), 'test_export') #1 /var/www/html/includes/config.php(12): require_once('/var/www/html/i...') #2 /var/www/html/includes/top.php(2): require_once('/var/www/html/i...') #3 /var/www/html/index.php(313): require_once('/var/www/html/i...') #4 {main} thrown in /var/www/html/includes/config_db.php on line 17