Removing a node from the replica set

MyReplicaSet:PRIMARY> rs.status()['members']
[
        {
                "_id" : 0,
                "name" : "localhost:27017",
                "health" : 1,
                "state" : 1,
                "stateStr" : "PRIMARY",
                "uptime" : 1108,
                "optime" : {
                        "ts" : Timestamp(1527847161, 1),
                        "t" : NumberLong(1)
                },
                "optimeDate" : ISODate("2018-06-01T09:59:21Z"),
                "electionTime" : Timestamp(1527846189, 2),
                "electionDate" : ISODate("2018-06-01T09:43:09Z"),
                "configVersion" : 2,
                "self" : true
        },
        {
                "_id" : 1,
                "name" : "localhost:27018",
                "health" : 1,
                "state" : 2,
                "stateStr" : "SECONDARY",
                "uptime" : 178,
                "optime" : {
                        "ts" : Timestamp(1527847161, 1),
                        "t" : NumberLong(1)
                },
                "optimeDurable" : {
                        "ts" : Timestamp(1527847161, 1),
                        "t" : NumberLong(1)
                },
                "optimeDate" : ISODate("2018-06-01T09:59:21Z"),
                "optimeDurableDate" : ISODate("2018-06-01T09:59:21Z"),
                "lastHeartbeat" : ISODate("2018-06-01T09:59:29.066Z"),
                "lastHeartbeatRecv" : ISODate("2018-06-01T09:59:28.171Z"),
                "pingMs" : NumberLong(0),
                "syncingTo" : "localhost:27017",
                "configVersion" : 2
        }
]

Remove the last node in the replica set

MyReplicaSet:PRIMARY> rs.remove('localhost:27018')
{
        "ok" : 1,
        "operationTime" : Timestamp(1527847202, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1527847202, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}

MyReplicaSet:PRIMARY> rs.status()['members']
[
        {
                "_id" : 0,
                "name" : "localhost:27017",
                "health" : 1,
                "state" : 1,
                "stateStr" : "PRIMARY",
                "uptime" : 1205,
                "optime" : {
                        "ts" : Timestamp(1527847261, 1),
                        "t" : NumberLong(1)
                },
                "optimeDate" : ISODate("2018-06-01T10:01:01Z"),
                "electionTime" : Timestamp(1527846189, 2),
                "electionDate" : ISODate("2018-06-01T09:43:09Z"),
                "configVersion" : 3,
                "self" : true
        }
]

Connect to the last replica set node, which we removed, and check rs.status()

mongo mongodb://localhost:27018

MyReplicaSet:OTHER> rs.status()
{
        "state" : 10,
        "stateStr" : "REMOVED",
        "uptime" : 440,
        "optime" : {
                "ts" : Timestamp(1527847202, 1),
                "t" : NumberLong(1)
        },
        "optimeDate" : ISODate("2018-06-01T10:00:02Z"),
        "infoMessage" : "could not find member to sync from",
        "ok" : 0,
        "errmsg" : "Our replica set config is invalid or we are not a member of it",
        "code" : 93,
        "codeName" : "InvalidReplicaSetConfig",
        "operationTime" : Timestamp(1527847202, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1527847202, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}