Persistent connection timeout

 
    We support a web server on z/OS mainframes.  In this product, we
support HTTP 1.1 persistent connections.  We routinely return a response
with Connection: Keep-Alive headers.  If the connection remains idle for
a while, we simply close the connection.
 
    Now I am getting a request to change this behavior.  I am being
asked, after the idle timeout,  to send an EXTRA response, with a
Connection: Close header.  This seems odd to me.  Sending an extra
response seems like it introduces an instability:  If the client sends a
request at the same time as we are sending the extra response, the
client could think we processed the request, when we did not.
 
    How do other servers handle the idle connection timeout?  
 
Fred Bohle
Progress Software