This ticket added a new serverStatus output field - "defaultRWConcern" - that is included by default. This field is a BSON object that may contain the following fields:
- defaultReadConcern -> Optional field representing the default read concern set by an administrator through the setDefaultRWConcern command. Present if a default is currently set.
- defaultWriteConcern - Optional field representing the default write concern set by an administrator through the setDefaultRWConcern command. Present if a default is currently set.
- epoch -> The epoch (unique generation id) of when the default read or write concern was last set. Present if a default has ever been set.
- setTime -> The wall clock time when the default read or write concern was last set by an administrator. Present if a default has ever been set.
- localSetTime -> The wall clock time when this node updated its understanding of the default read or write concern. Always present, even if a default has never been set.
Notably when FTDC calls serverStatus every second, this section is disabled. FTDC instead calls getDefaultRWConcern on every file rotation to collect the defaults.