I setup a v3.2 replica set with 3 members, and let it work as a config server of my mongos. When I check the log, I see a lot of "update" commands while these operations look successful within 1 second. I believe they should not be there, because I already set all log verbosity to 0, and "operationProfiling.mode" to "off", in my config file. My normal replicas seems don't have this problem.