• This was reported in Windows environment
• auth is used
• accessing data via MongoS.
• readPreference is PrimaryPreferred
  When Primary goes down, queries are retrieved from the secondary, but with 1 second delay

Developer Notes:
1. App has persistent connection to mongos with auth so it is not creating fresh connections to mongos
2. Topology
App -> MongoS (on Computer A) -> Primary (on Computer B), and Secondary (on Computer A)
3. MongoS tries to make a connection to Primary (which is down as part of test case), receives a ICMP Port Unreachable message, and then tries to connect to the Secondary. The 1 second delay is largely the ICMP port unreachable timeout.