On 2024/02/05 15:17:29 Volkan Yazıcı wrote:
>
> AFAIK, nested logging is not a documented feature. Yet one can find several
> tickets people has filed issues that were fixed by us. Hence, it is safe to
> conclude that it is used.
You are correct that it is not documented. Nor should it be. As you are seeing
you cannot count on how it will behave. I believe any unit tests that expect a
particular behavior should be removed.
>
> I also don't know why recursion is not allowed in `AppenderControl`.
> (Related history is too old and could not get in while migrating from SVN
> to Git.)
Recursion is not allowed because it creates a stack overflow exception. For
example, The user logs a message that routes to an Appender that uses a
framework that logs a message. That message gets routed back to the same
Appender which again calls the same framework which logs a message. This will
endlessly repeat. The recursion check prevents this from happening and the
nested log message is discarded. This is actually the ONLY behavior of nested
logging that should be documented and guaranteed. Passing objects to logging
that themselves perform logging as they are formatted has to result in the
unpredictable category since the formatting cannot be guaranteed to occur the
same way under all conditions.
Ralph
