Re: Persistent connections???

From: "David Gibbs" <dgibbs@xxxxxxxxxx>
> Can someone give me a quick explanation about, or point me to a good
> resource on, persistent HTTP connections?

The HTTP Server "PersistTimeout" and "MaxPersistRequest" directives can be
used in conjunction with the HTTP "Keep-Alive" header to establish a
persistent connection.  It ensures that a connection is not dropped after
the response is sent to the browser.

> I understand the concept of persistence, but am unsure how it
> applies to a HTTP session.

No session is established with a Persistent HTTP Connection.  You may be
thinking of Persistent CGI, or how sessions are managed by Websphere.  By
the way, my Relational-Web product also supplies an API to support sessions.

> I need to find out if a persistent connection means that a connection is
> established with the remote http server and that same connection is
> maintained until closed by the client.

A persistent connection basically tells the client to not close the socket
after the request is completed.  Most browsers support it.  It also defines
a time period in which the server will not close the socket.  It improves
network performance.  Has nothing to do with sessions, or tracking client
state across multiple requests.

A persistent connection appears to place a lock on one of the HTTP server
threads.  If you have 40 threads active, and 40 connected users, the next
user attempting to connect to the site will be denied service.

Nathan M. Andelin
www.relational-data.com