1 - you do not have redundancy compared to running with 3 nodes
2 - need extra RAM and disk space for the oplog
3 - need extra CPU for updating the oplog
But to
you have no choice but to run with replica set.
1 - you do not have redundancy compared to running with 3 nodes
2 - need extra RAM and disk space for the oplog
3 - need extra CPU for updating the oplog
But to
you have no choice but to run with replica set.