This program is pretty slow. Thanks to the caching, repeated visits from the
same address will only result in one lookup. Therefore large files will be
processed proportionally faster than small ones.

The load from this program is very light, because it spends most of its time
waiting for the resolver. This also means that large files can take quite some
time to process. The solution is to split the log file and run several
resolution processes in parallel. This is done by the script splitwr:

        splitwr logfile > logfile.resolved
        webalizer logfile.resolved
        rm logfile.resolved

By default, splitwr runs 20 parallel resolution processes. The number can be
changed by editing the script.