Whether DDS supports different types of instance changes
Currently, DDS does not support different types of instance changes. DDS provides a variety of architectures, including cluster, replica set and single node, which cannot be changed between different architectures.
Does DDS support adding nodes
DDS replica set supports the expansion of the number of nodes, for example, a 3-node replica set can be expanded to 5-node or 7-node. The sharded cluster supports adding mongos nodes and shard nodes.
Whether DDS is available during shard node expansion
Yes, the service availability of the database is not affected during the expansion of shard node.