Why we are encouraged not to use arbiter?

Hello,

On Mongo DB Replica Set lecture, the instructor explained to be very careful to use the arbiter?

Why? Can you give us more information and detail explanation?

Thank you,
-Laurentius

Arbiters do not hold a copy of the data.

Adding to @steevej-1495’s reply, arbiters can not become primary and is added to vote for elections in case of failover.

We should be careful to not to host an arbiter on the same server as primary or secondary members of the replica set.

Reason being if the server where your primary and arbiter is hosted goes down then you will also lose your majority voting which is why at the first place we keeps arbiter.

Kanika