//begin code
var m = MongoServer.Create("mongodb://192.168.1.110:27117,192.168.1.112:27117/cache?replicaset=cacheset&slaveok=true");

var col = m["cache"]["flatdoc"];
var q = Query.In("_id", BsonArray.Create(new[]

));

//this will throw: not master
var res = (from d in col.Find(q) select d).ToList();

//this will also throw: not master
res = (from d in col.Find(q).SetFlags(QueryFlags.SlaveOk) select d).ToList();

//end code
/*
The only way for this to not throw is to exclude slaveok=true from mongo url and
calling SetFlags(QueryFlags.SlaveOk) on the cursor before use.

I hope this helps
*/