[thelist] File delivery system?

Bill Moseley moseley at hank.org
Sat Mar 24 10:31:34 CDT 2007

On Sat, Mar 24, 2007 at 03:03:39PM +0000, kasimir-k wrote:
> I would have thought that if the connection is still open after the file
> has been output to the client, then I could be pretty sure that the
> client has received the file.

No, you can't assume that.

> > Are you sure there isn't a proxy sucking up the file and closing the
> > connection before the download completes?
> And the proxy would keep the file to itself and not pass it on to the
> client? Is this really possible?

The proxy could close the connection to your server but then the
download could still be aborted between the person downloading and the
Proxy.  A proxy's (and reverse proxy's) role is often to buffer between
slow clients and resource intensive servers to free up the servers to
serve other clients.  Think about AOL, for example.

> And after reading
> http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.44
> I'm under the impression that the server sends this to the client, and a
> proxy shouldn't add this on its own.

Right, shouldn't is the appropriate word.  There's a lot of stuff that
IE shouldn't do but does do.  Just pointing out that things happen
beyond your control.  It's the Internet, after all. ;)

> But if the idea is to limit the number of downloads, then both of these
> approaches fail - the user could download the file many times over the
> given period, and reply "no" to the question.

And that's different than them downloading it once and copying it multiple
times on their own machines?

Bill Moseley
moseley at hank.org

More information about the thelist mailing list