After experiencing some more problems, it seems my earlier explanation doesn't quite explain everything (though it is still valid). Some requests keep returning a completely empty page, and it turns out they do not even cause process-request to be called (or the loop in process-connection to go through a new iteration) -- so it might be an apache or mod_lisp problem with chunked or keep-alive connections. For your reading pleasure, I included the headers that apache sent me for a normal working request, and for a failed one...

Here's the working one (just returning a 3-character test page that said 'foo'):

Date
Sun, 05 Nov 2006 09:42:38 GMT
Server
Apache/1.3.34 (Unix) (Gentoo) mod_lisp/2.42
Content-Length
3
Keep-Alive
timeout=15, max=99
Connection
Keep-Alive, Keep-Alive
Content-Type
text/html; charset=iso-8859-1

And here is the strange one (obtained by refreshing the very same url, note the lack of content-lenght -- both returned 200 OK):

Date
Sun, 05 Nov 2006 09:42:35 GMT
Server
Apache/1.3.34 (Unix) (Gentoo) mod_lisp/2.42
Keep-Alive
timeout=15, max=100
Connection
Keep-Alive
Transfer-Encoding
chunked
Content-Type
text/plain

The problem only seems to occur when refreshing after waiting for a bit. When refreshing multiple times in a row, I always get the test page, but if I wait a few minutes and then refresh, the first try usually gives the empty page. Has anyone experienced something like this?

Regards,
Marijn Haverbeke