Converting a Replica Set to a Sharded Cluster | MongoDB Blog` Converting a replica set to a sharded cluster is now possible with Cloud Manager Automation, allowing for easier scaling of deployments. To do this, users can select the "Convert to Sharded Cluster" option on their deployment page and enter necessary details such as host selection and port configurations. After reviewing and deploying the conversion, users must modify their application to connect to the newly formed mongoSes instead of the original replica set. The automation process does not automatically activate sharding for specific databases and collections, leaving these steps to the user's discretion.