How to Write Useful Log and Trace
Messages 
Use
This section will help you understand in more detail the requirements of logging and tracing related to the content of log or trace messages. The section distinguishes between the two main types of messages: Log messages to permanently record the events and status of a software system, and trace messages to analyze a software system in detail from a programmers standpoint as exceptional procedure.
The content of a message must be carefully designed with respect to the addressees and the message type (trace or log message) chosen. Trace messages are intended for persons with development skills and a deep understanding of the application, whereas log messages are intended for a much broader audience with different skills and backgrounds. In general it is always a good idea to use a simple “four-eye-principle” to check, if an appropriate other person is able to understand the message without intensive additional explanation.
Before speaking about the content of messages, the organization of messages has to be discussed. For this it is essential to understand the possible addressees of your messages to provide understandable and suitable messages. At next, typical types of log and trace messages are described. This will help you to understand in more detail, which kind of message belongs into which main type (log respectively trace message) and how such a message is normally prioritized. Finally, after all the organizational tasks, the most important part, the content of a message, is described.
For more information, see Logging and Tracing.
Prerequisites
It is advisable to have a basic knowledge of the SAP Logging API, or at least to be familiar with the term “severity” in the meaning of “level of importance for a message”. You must also know the basic difference between categories (as logical destination for log messages) and locations (as logical destination for trace messages).
See also: