Does hidden priority-0 replica count when calculating fault tolerance?

Question

We have a mongdodb cluster with 3 replicas in one. We are planning to add one more replica on cloud. The replica on cloud is set as hidden and priority-0. If we include the hidden the total no. of nodes will be 4, which is not recommended according to this doc.

I am trying to understand if hidden replica count against fault tolerance calculation.

Answer 1

OK, you have already three voting members, that's perfect!

When you bring this hidden member, with default settings, it will take part of voting and now we have even count of votes... Not good!

But there is a solution! You must configure that hidden nodes voting count to zero (0), here is more info!