I need to put the two mongodb3.2 (copy) to upgrade to 4.2, for a smooth transition, the business is not to stop, so I think can fit up a 4.2 server added to the copy of the concentrated, such data can be synchronized to a temporary server, and then the two original can stop directly installed a new version 4.2, and then join in the cluster, data synchronization is completed temporary that can be removed, I wonder if this is feasible? Better if you can provide the relevant documents, the TKS