Question

Point out the wrong statement.

(a) The oplog is a special capped collection that keeps a rolling record of all operations that modify the data stored in your databases

(b) MongoDB applies database operations on the primary and then records the operations on the primary’s oplog

(c) The primary members then copy and apply these operations in an asynchronous process

(d) None of the mentioned

The question was posed to me during an interview.

I need to ask this question from Replication Processes topic in chapter Replication Concepts, Processes and Replication Set of MongoDB

Answer 1

Correct option is (c) The primary members then copy and apply these operations in an asynchronous process

To explain I would say: All replica set members contain a copy of the oplog, in the local.oplog.rs collection, which allows them to maintain the current state of the database.