Fatal error: Uncaught MongoDB\Driver\Exception\ConnectionTimeoutException: No suitable servers found (`serverSelectionTryOnce` set): [connection refused calling hello on 'localhost:27021']. Topology type: Single in /usr/share/php/vendor/mongodb/mongodb/src/functions.php:622 Stack trace: #0 /usr/share/php/vendor/mongodb/mongodb/src/functions.php(622): MongoDB\Driver\Manager->selectServer() #1 /usr/share/php/vendor/mongodb/mongodb/src/functions.php(689): MongoDB\select_server() #2 /usr/share/php/vendor/mongodb/mongodb/src/Collection.php(393): MongoDB\select_server_for_write() #3 /usr/share/php/vendor/mongodb/mongodb/src/Collection.php(357): MongoDB\Collection->createIndexes() #4 /home/www-0/m1/index.php(35): MongoDB\Collection->createIndex() #5 /home/www-0/m1/index.php(57): __init->__destruct() #6 {main} thrown in /usr/share/php/vendor/mongodb/mongodb/src/functions.php on line 622