Abstract: A method and system is disclosed for monitoring an operation of a distributed data processing system. The system can include a plurality of applications running on a plurality of host processors and communicating with one another, such as through a message passing technique. The method includes steps executed in individual ones of the plurality of applications, of (a) examining individual ones of generated API calls to determine if a particular API call meets predetermined API call criteria; (b) if a particular API call meets the predetermined API call criteria, storing all or a portion of the content of the API call as a stored event; (c) processing a plurality of the stored events to identify logically correlated events, such as those associated with a business transaction; and (d) displaying all or a portion of the stored API call content data for the logically correlated events.