Good question. I have no idea as I have never used Log4Perl. The following questions come up when I read your question:

• Have you tried it and seen any errors?
• Are you logging from multiple threads to the same "log"?
• Have you tried putting a lock around the actual logging (if you see problems with logging).
• Is there a test-suite?

I don't see any immediate reasons why there would be any problems using log4perl with threaded programs. But I could easily be very wrong.

Liz