I use mongodb 4.0.10. I want to establish a quorum for a cluster of one primary node and two secondary nodes as written here. When the number of nodes is less than the quorum, 3 nodes in my case, cluster goes to readonly (no election).
I`ve tried to set priority of two nodes to 0, in this case if primary goes down, there is no election, but if one of secondaries goes down, old primary still exists.
UPDATE: According to MongoDB docs terminology is it possible to set a replica set Fault Tolerance to zero? It means that if any of cluster nodes goes down new primary will not be elected.
As I understand there is no quorum mechanism in mongodb replica set, but expected possibility to perform write operations only if all nodes are alive can be achieved by deploying two-members cluster or by setting a write concern to 3 in the mongodb client as mentioned here.