[Looks like it didn't work the first time with common-lisp.net - maybe due to my misconfiguration of SquirrelMail. I'll try it again. Note that Peter has already pointed out my mistaken assumption.]
I'm sitting in a train and trying to send this via my cell phone. Let's see if it works... :)
I've looked at the source code of mod_lisp.c (version 2.33) and Apache (1.3.29) and I'm beginning to ask myself whether the "Keep-Socket" option makes any sense at all. What I see with my limited knowledge of Apache is the following:
1. The actual content handler in mod_lisp.c which is called each time a new request comes in (from the client) is the function lisp_handler.
2. To get a socket, lisp-handler calls OpenLispSocket.
3. OpenLispSocket uses ap_psocket (using the global variable SocketPool) to get a socket from Apache.
4. ap_psocket is defined in Apache's src/main/alloc.c and basically just calls ap_psocket_ex.
5. ap_socket_ex always unconditionally acquires a new socket via socket(7). The pool which is its first argument (and which is SocketPool from above) is only used for cleanup purposes.
So, as a consequence, I cannot understand if and how the socket used by lisp_handler is ever going to be re-used.
I'm sending a copy of this email to mod-lisp-devel because Marc is the authoritative source for this kind of questions... :)
Cheers, Edi.