If a thread is ever interrupted immediately followed by a logging call using a prudent FileAppender then the FileAppender is stopped and no logging can be done by any other thread.

FileLockInterruptedException is thrown by FileChannel.lock used in FileAppender.safeWrite. This exception should not stop the entire appender, for my use cases it would be enough to just catch the exception and reset the interrupted flag.

I've attached a very simple unit test that demonstrates this issue.