I have an issue with connections failing in a certain scenario:

Architecture:

website#1 with primary#1
website#2 with secondary#2
website#3 with secondary#3

Settings: new MongoClientSettings

{ ReplicaSetName = "rs", Servers = < 3 server names >, ConnectionMode = ConnectionMode.ReplicaSet, ConnectTimeout = new TimeSpan(0,0,60), ReadPreference = (slaveOk) ? ReadPreference.Nearest : ReadPreference.Primary, WriteConcern = WriteConcern.Acknowledged, }

–
I run this command:
var client = MongoClient(Settings);
await client.GetDatabase("admin").RunCommandAsync("

{replSetGetStatus:1}

")

and generally receive a correct response with myState either being 1 or 2.

–

However, sometimes whilst these sites are running I will take offline secondary#2 - and run up a local non-rs instance on port 37017. When I do that, website#2 begins to respond with:

A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = WritableServerSelector, LatencyLimitingServerSelector

{ AllowedLatencyRange = 00:00:00.0150000 }

}. Client view of cluster state is { ClusterId : "1", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "

{ ClusterId : 1, EndPoint : "Unspecified/127.0.0.1:27017" }

", ....

Now - I would have expected the website to fall over to retrieve secondary#3 - but its not doing that.

Am I doing something wrong?
Should perhaps my MongoClient be more globalized within the AppDomain (maybe - but is it related).

Hope you can help.