Simultaneous connections and sharing to a single HTTP server

Brian Cryer

2005-11-15 11:04:18 UTC

Post by Andrew Yao
Hi All,
I have a question
From KB (Q183110) http://support.microsoft.com/kb/q183110/
WinInet limits connections to a single HTTP 1.0 server to four
simultaneous connections. Connections to a single HTTP 1.1 server are
limited to two simultaneous connections.
Suppose I have an Internet Explorer process running, and currently there
is an open connection to HTTP server X. If I open another IE process, that
also fetchs URL from HTTP server X, will/can the second IE process simply
use the existing connection (in the first IE process)?
thanks
Andrew

My experience is that the WinInet dll enforces these connection limits quite
rigidly.

As far as the browser is concerned, unless you are in the process of
downloading a big file, it really isn't noticeable. This is because:

1. IE caches a lot (and therefore so does the web browser component).

2. Each request is normally dealt with quite quickly (consider how long
it takes to download say a 10kb html file or image). Okay, there might be a
number of requests for files per page, but most of this will be cached for
next time.

I suspect you are thinking that when the browser visits a page that it opens
a connection and keeps it open. This isn't the case. It makes a request for
each file it needs, but these are dealt with individually. There is no
connection to use that the other browser could share - its not like say FTP
where you establish a connection and then use it. HTTP doesn't maintain a
connection between requests.

Hope this helps.

--
Brian Cryer
www.cryer.co.uk/brian