Re: Only 2 concurrent connections with window.open()?

From: Steve van Dongen [MSFT] (stevevd_at_online.microsoft.com)
Date: 03/18/04 

Date: Wed, 17 Mar 2004 19:43:27 -0800

How to Configure Internet Explorer to Have More Than Two Download
Sessions
http://support.microsoft.com/default.aspx?scid=kb;en-us;282402

Regards,
Steve

On Wed, 17 Mar 2004 20:33:18 -0000, "Chris Barber"
<chris@blue-canoe.co.uk.NOSPAM> wrote:

>Each instance of IE is (by HTTP standards) limited to 2 http 'connections'.
>You can change this in the registry (not sure where anymore).
>
>Your first scenario creates four windows three of which are just new window
>instances from the same common instance of IE.
>Your second scenario creates four instances of IE each of which can have 2
>connections.
>
>Chris.
>
>"sherard" <sherard@nospam.nospam> wrote in message
>news:13F16B4F-8A51-4C34-A7F6-5D24556F73EE@microsoft.com...
>I have noticed some odd behaviour and am hoping that someone has a
>resolution.
>
>I am using client side JScript in Internet Explorer 6 SP1 to use a page to
>open up 4 new browser windows, using window.open(), with each new page
>navigating to the same URL (an ASP page).
>
>An example of the client-side code would be as follows:
>
>var URL = "http://myserver.com/mywebpage.asp";
>for (var i=0; i<4; i++)
>{
> var newWin = window.open(URL);
> newWin.focus();
>}
>
>4 new browser windows get opened as expected, and it is evident that all are
>trying to access the required URL. However. by monitoring the perfomance
>counters on the Web server (IIS 5, Windows 2000 SP 3), I can see that only 2
>requests get serviced at any one time, with two of them being serviced when
>the original two have finished. I have observed this behaviour using the
>Active Server Pages 'Requests Executing' and 'Requests Queued' counters on
>the server. An important point to note is that the Requests Queued counter
>always reads 0, and it is almost as if only two requests are made by the
>client browser at any one time, i.e. they never reach the web server until
>the first two have finished.
>
>However, when I MANUALLY open up 4 different browser windows on the client
>machine, and navigate to the same URL in all of them and at the same time,
>all 4 get processed simultaneously (again I can see them all executing using
>the 'Requests Executing' counter), which leads me to believe that it is a
>problem with the client browser or the window.open() mechanism, and nothing
>to do with the Web server.
>
>The Web server is set to receive unlimited connections. The Web site is also
>set to use Windows Authentication, but I have tried setting it to Anonymous
>User as well and it makes no difference to the behaviour.
>
>Does anyone know how to resolve this?
> 

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