squid maintains a thorough access log, typically in /var/log/squid, aptly named
There is a utility named
Squid Analysis Report Generator, that can be used to parse this log, gather useful statistics from it, and generate a friendly and convenient Web-browsable report that you can examine with any Web browser.
In its simplest form, you invoke
sarg with the name of the log file you wish to examine, like this:
For bandwidth utilization::
The basic concept is to set up per-host (class 3) delay pools in
squid.conf, then set each of them to the maximum amount of bandwidth I want to allow per user per day. Then, set the "fill" rate to be that maximum amount of bandwidth divided by one day's worth of time, so each delay pool will fill completely in one day.