Während der Programmausführung kommt es immer zu Ereignissen und Zuständen, die für die Fehlersuche und die Programmanalyse interessant sind.

  • Admin: richtet das Programm ein und kümmert sich um dessen Betrieb, vorrangiges Interesse an der Lauffähigkeit
  • Entwickler: entwickelt das Programm
  • Support-Mitarbeiter/Nutzer: arbeitet mit dem Programm und interessiert sich für dessen Funktionsfähigkeit, korrekte Arbeitsweise

Error

  • Target: Service Admin
  • Reason: Bad events, where no fallback or auto-recovery is possible and manual action from the Admin is required
  • Example:
    • unhandled exception
    • database connection failed
    • invalid config setting

Warn

  • Target: Service Admin
  • Reason: Bad events, where fallback or auto-recovery exists, but the admin should care about, because they should not happen too often
  • Example:
    • database query failed due to lock contention and a rerun of the query happens
    • Connection to remote system failed

Notice

  • Target: Service Admin
  • Reason: Interesting actions which are helpful for reporting and examination of user error reports; syslog says »normal, but significant, condition«
  • Example:
    • login/logout of users
    • new entities (account, business unit, invoice, chat room)
    • broken user requests

Info

  • Target: Developer, Reporting system, someone who analyses problems
  • Reason: informational message
  • Example:
    • request … handled within … seconds
    • save attachment to file …
    • connecting to …
    • federation_transaction_transmission_loop TimeoutError('',)
    • federation_transaction_transmission_loop HttpResponseException("403: b'Forbidden'",)

Debug

  • Target: Developer
  • Reason: messages showing some interesting behaviour what the service is doing, but mostly useful for developers.
  • Example:
    • Lock acquired/released
    • Value of variables on some points
    • Number of written bytes

Trace

  • Target: Developer
  • Reason: Verbose message printing the state of a variable or a point in the code. Only interesting during development.