Which of the following statements are true about MongoDB replication? [closed]

Question

1. The minimum sensible number of voting nodes to a replica set is three.
2. MongoDB replication is synchronous.
3. The Mongo shell is capable of attaching to a replica set and automatically failing over.
4. By default, using the new MongoClient connection class, w=1 and j=1.
5. The oplog utilizes a capped collection.

I have selected 1,3,5 in answers but still get wrong answers. can anyone help me which one is right options for replication?

Answer 1

Only 1st and 5th are true.

2) MongoDB replication is *a*synchronous.

3) For mongo shell, we need to do manual fail over.

4) MongoClient connection class default write concern is w=1 and j=0.

Answer 2

1. Is correct, you can read more about here: http://docs.mongodb.org/manual/core/replica-set-architectures/
2. Not correct. MongoDB replicattion is async.
3. Not correct. Once connected to replSet you need manually shutdown sever to cause fail over.
4. Not correct. You can read MongoClient doc here: http://mongodb.github.io/node-mongodb-native/driver-articles/mongoclient.html Default value's {w: 1, j:false}
5. Correct. OpLog is a capped collections.