While I have yet to delve deeply into it, the default locking of log files by log4net hinders concurrent reads. The ExclusiveLock locking model (default) seems to keep the change determination based on last write, or file size to fail (or at least not work in a timely manner). I know there is a whole bunch of detail around this that I haven’t looked into, however setting the locking model to MinimalLock addressed the problem as I was seeing it (allowed concurrent reads to detect changes).