Configure a config server and a mongos that connects to it, both running as Windows services. Start both, connect to the mongos from the Mongo shell, and run the following:

use admin
db.runCommand({ shutdown: 1 })

The Mongo shell will stall for a few seconds while the server is unresponsive and then eventually time out. If you observe what's happening in the Windows Services window, you'll notice that the mongos remains running but unresponsive while the Mongo shell is stalled. Once the Mongo shell stops trying to communicate with it, it immediately stops. (Please note that the Windows Services window does not automatically refresh, so it is necessary to repeatedly press F5 in order to see this.) This behavior is a regression that was introduced in MongoDB 3.2.5. If you do the same thing with earlier versions of MongoDB, the Windows service stops immediately and the Mongo shell just displays some error messages without stalling. The issue was detected because it is causing an Automation Agent tests, FickleUtilSuite.TestIsLowestMongosUpInCluster, to fail on Windows only.

CC mark.benvenuto