Summary: This is a test bug - loggers held in local variables can be arbitrarily gc'ed if that variable is no longer used. The fix makes sure that the loggers won't be arbitrarily gc'ed before the test is complete.
Reviewed-by: mchung

Summary: Fixes several race conditions in logging which have been at the root cause of intermittent test failures.
Reviewed-by: mchung, plevart