This depends on how tight the relationship is between programs.

I prefer that all programs in the same application send theirs logs to the same repository, or at least does so for each logical group. This helps. When you have an issue with an application, it is not always possible to determine from onset, the program that is causing the problem. If the logs are everywhere, it will be very laborious for you to search around.

Obviously the log messages should be nicely formatted, and other than the error message, also provide the following:

• The name of the binary
• Time of logging
• If possible, the line of the source code. (or at least somewhere close)
• It will be very helpful, if you can log things like data used, SQL statement submitted, SQLCODE etc. (things that allow you to determine problem without repeating it, or things that make the repeating possible)