le AccessLogValve instances
    are used, they should be configured to use different output files.</p>

    <p>If sendfile is used, the response bytes will be written asynchronously
    in a separate thread and the access log valve will not know how many bytes
    were actually written. In this case, the number of bytes that was passed to
    the sendfile thread for writing will be recorded in the access log valve.
    </p>
  </div></div>

  <div class="subsection"><h4 id="Access_Log_Valve/Attributes">Attri