setting slaveOK() does not result in a secondary read preference through mongos

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      Although slaveOk() is deprecated, if it is in use the expectation is it should behave the same as setting ReadPreference.secondaryPreferred();

      Instead the queries are seen with { $readPreference:

      { mode: "primary" }

      } explicitly set when going through a mongos

      Under 2.6 the following java sample will correctly result in a query to a Secondary. The same code in 2.7 or above will result with the primary $readPreference set.

      import com.mongodb.*;
import java.net.UnknownHostException;

public class TestSlaveOK{
	public static void main(String[] args){
		Mongo m = null;
		DB db = null;
		DBCollection coll = null;
		
		try{
		
		MongoOptions mongoOptions = new MongoOptions();
		mongoOptions.slaveOk = true;

		m = new Mongo("localhost:27017", mongoOptions);
		db = m.getDB("test");
		}
		
		catch(UnknownHostException uhe){
		System.out.println("UnknownHostException:" + uhe);
		}
		coll = db.getCollection("test");
		DBObject query = new BasicDBObject("x", "100");
		DBObject obj = coll.findOne(query, null);	
	}
}

      Looking at the highest verbosity logs (or capturing the query in another way) under 2.11.1 will show the query executed with { $readPreference:

      { mode: "primary" }

      } on both the mongos and the Primary node:

      Tue Apr 23 16:37:37 [conn28] shard query: test.test  { $query: { x: "100" }, $readPreference: { mode: "primary" } }

              Assignee:
              Jeffrey Yemin
              Reporter:
              Andre de Frere
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                Created:
                Updated:
                Resolved: