rnal triggers for report generation. Defaults to
<code>'SIGUSR2'</code>.</p>
<p><code>filename</code> specifies the name of the output file in the file system.
Special meaning is attached to <code>stdout</code> and <code>stderr</code>. Usage of these
will result in report being written to the associated standard streams.
In cases where standard streams are used, the value in <code>directory</code> is ignored.
URLs are not supported. Defaults to a composite filename that contains
timestamp, PID and sequence 