@Doug_Duncan thank you. i understand this post. but here is my doubt.
Let’s say that i have a singleNodeReplicaSet - it accepts both read/write. then i add 2 additionalnodes to this singleNodeReplicaSet which becomes a 3NodeReplicaSet.
So, Once a singleNodeReplicaSet that runs on its own is converted to 3NodeReplicaSet, i could never scaledown the 3NodeReplicaSet back to a singleNodeReplicaSet and make this singleNodeReplicaSet to accept read/write requests?