This isn't quite what you want, as it's not built in and requires some
minimal refactoring, but if you want your application messages to go
to a different file, you could just build a method much like
tornado.options.enable_pretty_logging() but attach it to a new logger.
Pass this new logger object around your request handlers either as a
class attribute (e.g., in a MyRequestHandler superclass) or via
request options. If the former, "self.logger" or thereabouts becomes
your application messages log, and logging.foo() methods remain the
tornado log.
-a