Engineer(s): Jesse 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. 2021-09-07: No update to target date. 2021-08-24: Setting target end date to 2021-09-17 Initially expected to take two weeks, but setting target end date to 6 weeks. This accounts for time ramping up. A plan for testing is still being investigated, since mocking the serviceId from the C++ driver is non-trivial. Adding serviceId to command monitoring events is in review.  ----