Session can't release

It would look almost identical to what you have now. You'd just add a counter value under the HTTP_REQUEST section that's used and then emptied in the CLIENT_CLOSED event.

Something like:

 
 when HTTP_REQUEST { 
   incr requestCount -1 
 ... 
 

And then in your client closed section, instead of incrementing by -1, you'd increment by $requestCount.

 
 when CLIENT_CLOSED { 
   log local0. "site $site request closed" 
   if { $site == "a" } { 
     incr ::total_active_clients_a $requestCount 
     set requestCount 0 
     if { $::total_active_clients_a <= 0 } { 
       set ::total_active_clients_a 0 
     } 
 ... 
 

That way you're always decrementing the "total_active_clients" value by the number of requests that were put through on this connection.

Make sense?

Colin