First, some terminology:

  • "logging" is used to describe the method by which significant events the program are formatted and routed to a destination. The term also covers the selection of events by the logging system, but only at the level of broad categories; it does not cover the the selection of events within a category.
  • "diagnostics" is used to describe the addition of features to the program that allows problems to be traced.

The difference between the two is fine and often blurred. For example, consider the requirement that the system be able to output debug messages related to the query at specific points in the query processing: as stated that would be part of the logging. If however, the requirement is to output debug messages for some queries but not others - the determination of "some" being by means of specific selection criteria related to the query itself - then although the output of the information falls within logging, the selection of the queries to be logged falls under the category of diagnostics.

The distinction used here is that logging is program-independent and primarily concerned with the recording of events; diagnostics is program-dependent, may require special code within the program to enable and will most likely use logging for some or all of its output.

These pages only cover logging.




Last modified 7 years ago Last modified on Oct 24, 2011, 1:30:13 PM