Re: Performance Problems with Probing

From: Jediah L. (rife_at_nospam.nospam)
Date: 08/25/04 

Date: Wed, 25 Aug 2004 16:18:19 -0400

Thanks Jeff.

In our case - we have approximatly 3,000 users - but they are all intranet
users - so we could force IE settings if it would help.

What we are finding to be the more specific problem is this.

When We have a method (executing on the client) in javascript inside of an
HTML page - that requests to download 10 XML files - it will attempt the
first as Anonymous - and the other 9 as authenticated (I may have stated
otherwise in a previous email - if so I apologize).

In our .Net smart client - the connections are stateless - so we open and
close a connection for each request - so when we request 10 XML files - we
end up trying ANON and then NTLM AUTH for each of the ten files - thus
making 20+ HTTP requests for the 10 requested files.

It would be nice if we could tell our Web Request object - don't bother
trying ANON - use the Credentials we supplied (We do supply the credentials
too).

The Question #2 I believe had more to do with the additional probing that
.Net does when using embeded Windows Form User Controls in IE. We have
found that even though we specify a probing path (/assemblies in our
example) - it always goes through a series of probes first no matter what -
so for a file named Search.dll it looks for this:

/Search.dll
/Search/Search.dll
/bin/Search.dll
/bin/Search/Search.dll
/assemblies/Search.dll - receives 401 as it was Anon
/assemblies/Search.dll - 200 / or 304

How can we force it to stop probing needlessly - besides moving all of our
assemblies into the root folder?

The Question #3 we have been expericing this issue very sporadically - one
minute it will cache - one minute it will not.

I've found when it is not caching - the client is not setting the
If-Modified-Since headers - although I can't figure out why. In our case -
the files haven't been modified in almost a week; and previous 200 responses
do return the Last-Modified header.

The Expiry headers are not set at all - and we continue to get sporadic
responses of caching and no caching.

Any other information / suggestions you can provide would be great.

Thanks!

""Jeffrey Tan[MSFT]"" <v-jetan@online.microsoft.com> wrote in message
news:Mefh9qOiEHA.3724@cpmsftngxa10.phx.gbl...
> Hi Jediah,
>
> Sorry for letting you wait for so long time.
> =====================================
> 1. Based on my understanding, your #1 requirement is disabling the
> anonymous authentication to improve your Asp.net application performance.
>
> First, this requirement can only be done at server side, because you can
> not force all the client customer browser(IE) to do anything. But again,
> this http authentication request can only be controlled at client IE side,
> because IE always send anonymous request, then with windows account
> information. This indicates that this requirement can not be
> controlled.(As
> I originally said, you can not control million client's browser setting)
> Second, the key performance issue of Asp.net Application is server side
> code parsing, Html code rendering and Html code client parsing, but not
> the
> HTTP request, so you may pay more attention to improve the application
> performance. For more information about improving Asp.net performance,
> please refer to:
> "Improving ASP.NET Performance"
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag/html/
> scalenetchapt06.asp
> Third, NTLM authentication is a complex authentication, which involves
> several HTTP request and authentication information exchange. And the
> first
> anonymous http request time can be ignored comparing with the NTLM
> authentication.
>
> 2. I think it is the same as the first question
>
> 3. First, you may check IIS setting's "HTTP headers" tabpage, if you set
> "Enable Content Expiration" with "Expiration Immediately".
> Second, using the siffer, you may check, if the IIS reponse has "no-cache"
> http header.
> Third, I think the problem may be on your specific IE side. You may do
> some
> test to confirm this:
> Does your problem machine request other server pages?
> Does other machine's IE also has this problem?
>
> ==================================================
> Thank you for your patience and cooperation. If you have any questions or
> concerns, please feel free to post it in the group. I am standing by to be
> of assistance.
>
> Best regards,
> Jeffrey Tan
> Microsoft Online Partner Support
> Get Secure! - www.microsoft.com/security
> This posting is provided "as is" with no warranties and confers no rights.
>

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