For example, "031114-173045.1234.5+6+7.9" means that
it is the 9th request from the client
in the session started at 17:30:45 on November 14 by the process of PID=1234.
The start of the session is recorded in LOGFILE as this:
Note that the reqnum part may not be unique because of parallel or
pipelined requests generated by a client as the owner of the session.
Note that the reqnum part for "%As" may not be incremented on each
request because the container of session identifier,
the opaque" parameter in Digest Authentication in this case,
may not be updated on each request.