Category of Parameter Group
You can specify instance startup parameters in a single-node instance or a replica set instance.
You can specify startup parameters for the config, mongos, and shard nodes in a cluster instance.
Use Precautions for Parameter Group
When you customize a parameter group, some default parameters cannot be modified. You can only modify some open and editable parameters.
When using user-defined parameters, set them within the range of the allowed values. Improper settings may make the instance unstable or abnormal upon startup.