Question

Point out the wrong statement.

(a) Even number of members ensures that the replica set is always able to elect a primary

(b) Arbiters do not store a copy of the data and require fewer resources

(c) You may run an arbiter on an application server or other shared process

(d) None of the mentioned

This question was addressed to me in an internship interview.

This intriguing question originated from Replica Set Deployment Architectures in chapter Replication Concepts, Processes and Replication Set of MongoDB

Answer 1

Right option is (a) Even number of members ensures that the replica set is always able to elect a primary

Easy explanation: If you have an even number of members, add an arbiter to get an odd number.