mongoc_application_performance_monitoring(3) on Linux
The text 478d80bfec73, as Debian 12 (Bookworm) shipped it.
Application Performance Monitoring (APM) The MongoDB C Driver allows you to monitor all the MongoDB operations the driver executes. This event-notification system conforms to two MongoDB driver specs: To receive notifications, create a mongoc_apm_callbacks_t with mongoc_apm_callbacks_new(), set callbacks on it, then pass it to mongoc_client_set_apm_callbacks() or mongoc_client_pool_set_apm_callbacks().