Web Server Activity.

Web Server Activity
Your Zeus server records logs of activity. You can examine these records using the Activity Monitor on your admin server, drilling down through an overview of downloads over the last 24 hours or 7 days to investigate the most active host headers on a single virtual server.
Each Zeus webserver talks to its local zeus.statd, informing it of its current activity. You can enable or disable this logging for individual virtual servers by enabling or disabling the mod_stats module. The local zeus.statd process records the activity in log files - virtual server, host header, hits and bytes transferred. The log files are stored in $ZEUSHOME/web/log/statd and are deleted or archived once they reach a certain age.
The Activity Monitor is completely cluster-aware (with several caveats), and can query the logs of all the machines in your cluster simultaneously.

For Example ...
Joe Webmaster runs a webserver farm of three machines; Samson, Goliath and Hercules. Goliath runs his admin server, and so appears as 'localhost' in his statistics reporting.
Samson and Goliath are not as powerful as Hercules, so his Zeus load-balancer compensates for this by directing more traffic to Hercules. Moreover, Samson was offline for some time several days ago.

He wants to know why his webservers are busy, so he drills down to look at the virtual servers running on Hercules:

His server farm is only running three virtual servers. 'Development' and 'Intranet' are relatively inactive. 'Customers' is handling a number of customer websites (using the Zeus subserver module), so he examines the host headers active on this virtual server.

www.saturn.com is clearly the most active website on his server farm.

Cluster Caveats
The Activity Monitor is cluster aware, with several restrictions. These restrictions do not apply if you only have one machine in your cluster, or have no clusters configured.

You cannot calculate the top n virtual servers or host headers across more than one machine. You can only make this calculation for the data from one machine in your cluster at a time.

You cannot display a snapshot of activity across all your clustered machines. You can only display an activity snapshot for one machine at a time.

Notes

You must have the stats module enabled for each virtual server you wish to view in the activity monitor.

Other logging facilities are also available: the mod_log module provides a configurable logging facility that records the Zeus server's activity in complete detail.

On a performance critical website, or in a benchmarking environment, you should disable the local zeus.statd process by setting the registry key in the webserver's global.cfg file of 'tuning!modules!stats!enabled' to 'No'.

Each morning at 00:30, each local zeus.statd runs the script $ZEUSHOME/web/bin/statd.cron.pl. This script deletes old statd log files, and can potentially be used as a hook to perform log file calculations, such as billing details.
Files older than 'tuning!modules!stats!days_to_archive' are archived to the folder named 'tuning!modules!stats!archive_dir' and then deleted. Both of these tuneables live in the webserver's global.cfg file.