Engineer(s): Jeff Summary: Support mongos instances behind a load balancer. This would require at least cursor / socket affinity and transaction / socket affinity so getMore and transactional operations always hit the same mongos instance. Cost in Eng Weeks: 2 Original | 2 To Date | 2 Est Final 2021-05-17: On track for 2021-05-21 Went into review last week and being reviewed actively 2021-05-03: Initial target end date of 2021-05-21 Reactive Streams driver support is nearly complete.  Expected to be in review by the time synchronous driver support is approved Added two additional weeks to account for reviews and responding to feedback, but this would likely wrap up sooner than 5/21