See who's hitting your web server the hardest up to the second with httptop
Advanced http log analysis packages like analog can give you very detailed report on who has been looking at what on your site. Unfortunately, log processing jobs can take quite a long time to run on a busy site, giving you detailed retrospective reporting but nothing about what's happening right now.
Another approach is to log all relevant web activity to a database and perform queries on it for real-time statistics. This method can give you instantaneous, to-the-hit reporting, as long as you have a database and web server powerhouse capable of supporting the additional load. On a very busy site, this simply isn't practical.
Somewhere in between lies httptop, a Perl script that attempts to give top-like reporting in real time, without the overhead of a database server. It expects to be given the path to an access_log file. Run the command like this:
$ httptop -f combined /usr/local/apache/logs/access_log
You'll be presented with a screen that refreshes every couple of seconds, sorted on hits per second. Just as with top, hit ? for a listing of available keys. They include such niceties as sorting by most recent hits or total hits, and optionally displaying the referring URL or domain, the requested URI, or remote requesting host.
If you have a bunch of VirtualHosts and would like to be able to simultaneously run httptop across all of them, ...