MongoDB cluster splits up replica set after 1st node in cluster is removed

[rainmaker2k]

I have an issue with the MongoDB cluster after the first node in the cluster gets removed. It seems to cause a new node to be created and initializes its own new empty replicaset.

For example when the host with the first node is brought down, a new node will be created. MongoDB does take care of electing a new primary, but it seems it can't find the existing cluster and the scaling script will start to create a new replica set for the new node and lose all the data from the existing node.

This issue might occur when the host with the first node running might be replaced.

edit: updated findings