WHEN I ENCOUNTER A SYSTEM that has already been in development or production for a while, the first sign of real trouble is always a dirty log.
Too much logging can be as useless as none at all.
In general, the best indication that everything is all right is that the messages at a lower priority are ticking along happily.
A cluttered log is an indication that the system will be hard to control once it reaches production. If you don't expect anything to show up in the error log, it will be much easier to know what to do when something does show up.