Ulric Eriksson <ulric@siag.nu>

This program is used in conjunction with Webalizer to get host names
rather than IP addresses in the statistics. Preprocess the log
files with webresolve to replace IP addresses with host names.
The program reads from stdin and writes to stdout:

	webresolve < access_log > access_log.resolved


I wrote the program to process access log files from Apache before
they are analyzed by Webalizer. Recent versions of Webalizer has
semi-working resolution built in, but not on all platforms, including
the one siag.nu runs on.

Each line is one record consisting of whitespace-separated fields.
If the first field starts with a digit, we assume that it is an
IP address which we try to look up. The rest of the line is ignored.
The result of the lookup is cached and the line written back with
the first field replaced by the host name, if lookup was successful.

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.


See INSTALL for installation instructions.