When a large number of logging entries are recorded, log rotation fails and the log entries are redirected from the web agent log files to the error log files of the web container. These redirected log entries get written as stderr. The log files then accumulate on the web container without being automatically deleted.
Workaround: During production, do not use fine-grained logging levels, such as levels 4 or 5. These logging levels are only appropriate for short periods of time, such as for debugging.