Re: Why requests come sequentually, not in parallel?

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Forgot to add
You can easily write your own custom Session object..
Google it, I recall it was a KB on Microsoft.com with full implementation

George.


"VH" <VH@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message news:4CBD741B-E125-4EC1-9220-D1435BC838E5@xxxxxxxxxxxxxxxx
Never mind my previous post. Of course, all requests accessing Session should
be serialized, unless they were required to be written in a thread-safe
manner. I wish there were a way to declare a page or a handler as thread-safe
to avoid perf penalty due to request serialization.

Thanks again,
Vlad.

"bruce barker" wrote:

you probably have session enabled for your handler. two requests to the same
session are serialized due to the design of session management. your image
handlers should not use session (IRequiresSessionState or
IReadOnlySessionState) as this will cause performance issues.

-- bruce (sqlwork.com)


"VH" wrote:

> Hi, all.
>
> Need help with what seems to be either connection, or threading problem > in
> my ASP.NET 2.0 application.
>
> The gist of the problem is this: IHttpHandler in my application serves > an
> HTML page that has two images (image A and image B) in it. Once the > HTML page
> is served, expected behavior is this:
> 1) receive request for image A,
> 2) receive request for image B almost at the same time as for A,
> 3) serve image A response,
> 4) serve image B response.
> Actual behavior is instead:
> 1) receive request for image A
> 2) serve image A response
> 3) receive request for image B
> 4) serve image B response
> The application acts as if it allows only ONE connection from the > browser
> instead of two. This decreases the performance (as experienced by > users)
> quite a bit.
>
> Additional details.
> My ASP.NET application has ASPX pages, ASMX web services and > IHttpHandler
> that serves resources described before. I suspected that the problem > may be
> caused by the running out of inbound connections on my (Vista/IIS7 with
> classic pipeline) dev box, but the same behavior is observed on IIS6 on
> Windows Server 2003.
> The strangest thing is that when tracing HTTP sessions using Fiddler, I > see
> that *browser sends both image requests requests virtually at the same > time*
> but second request reaches my IHttpHandler only after first one was > served! I
> played with ASP.NET threading settings to no avail. Requests served by
> IHttpHandler have somewhat longer latency by design: from milliseconds > to up
> to 9 seconds. Also, when I launch multiple browsers pointing to the > html page
> with images, I get requests from different browsers coming in parallel. > It
> looks like for some reason only requests from the same browser come in
> sequentially. Tried turning keep-alive on and off on the application > and it
> made no difference.
>
> Why would two requests sent by browser at the same time arrive in a > manner
> implying only one connection to the browser instead of two?
>
> Thank you,
> Vlad.

.

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