319test:PRIMARY> rs.add("ip-172-31-42-223")
{
	"ok" : 0,
	"errmsg" : "Quorum check failed because not enough voting nodes responded; required 2 but only the following 1 voting nodes responded: ip-172-31-42-224:27017; the following nodes did not respond affirmatively: ip-172-31-42-223:27017 failed with Connection refused",
	"code" : 74
}

The above error is simple: mongod isn't running on the node I'm attempting to add. The error message about quorum check is confusing.

Two things need fixing or at least checking:

• If the relevant code path (didn't read) really does some kind of quorum check, that is superfluous. A pre-condition to adding a node should be that I can connect to it. Doing any quorum check only makes sense after that condition is satisfied.

• The error message is confusing and irrelavant. It should just say "Connection refused".