Problem in tracking data transfers

[reis]

My server is hosting multiple sites and I need to track how much data the individual sites are moving in and out of the server (Apache/php4.4/mysql).

Problem is this: most of the sites are generated dynamically and are actually sharing a lot of files (graphics,...). This makes it impossible to track the amounts transferred from apache log. I can get the total amount transferred, but cannot tell how much the individual sites move data.

Is there any way to log the data with apache without using cookies? I could set a cookie to a visiting user with PHP to identify the site he is visiting. I know Apache can read the cookie and add that information to log (which would tell which site is moving the data), but cookies are not the most reliable way of doing this.

[Dijkgraaf]

You could always add
?site=sitecode
to the end of each image or other include URL
That way you know which site is serving up the contents.

[larryn]

Reis,

Why not enhance the log file format to include the server name:

[httpd.apache.org...]

Larry