Added param to configure mdc variables to be extracted before logging. Currently AccessLogValve runs after filterchain and therefore after the MDC has been cleared in most cases. To fix
Added AccessLogFilter. Also supports MDC though now not needed for original usecase.
AccessLogFilter now delegates logging to the underlying log framework. This distances the servlet from the remote connection configuration
Closing appender, when file changes or shutting down app can cause the thread to hang on the socket and all other loging threads block on the appenders monitor