Hi,

My webresource.axd aren't returning Http Status: 304 (pulled from client browser cache) and for the life of me I can't think why. They're returning 200, meaning reloading from server.

I've compiled in release mode and my compilation is set to debug="false". My browser is set to Automatically check for newer versions. I'm using ASP.NET AJAX and my ScriptResource.axd files ARE returning 304 status messages

I'm running IIS 6.0 on Windows 2003. I've looked at the traffic using Web Development Helper, Fiddler, and HTTP Analyzer 2 and it all says the same thing.

Here is a request to a ScriptResource 

GET /PROPERTY/ScriptResource.axd?d=xXHyRhQ39AVIH62TuZ--7Aa3mhABc_C5l6w0tTMaZe8lpxj8SVqoV2GONWlzRgaGj37GYaRpmJ8sWmzDivv-kPXtcvxsbxdAGJn7gbJMzKc1&t=633126710456040000 HTTP/1.1

Here is the response. 

(Status-Line):HTTP/1.1 304 Not Modified
Date:Thu, 28 Jun 2007 17:02:46 GMT
Server:Microsoft-IIS/6.0
X-Powered-By:ASP.NET
X-AspNet-Version:2.0.50727
Cache-Control:public
Expires:Fri, 27 Jun 2008 16:57:53 GMT
Last-Modified:Fri, 20 Apr 2007 17:04:05 GMT
Content-Length:0

Here is the request to my WebResource 

GET /PROPERTY/WebResource.axd?d=HJejXre1kvmpIOcutOouIZyuttFxyblLItct1wcaEJ2NdriLTugm-uG3PDwrnDecKB64Fa9TxqsfMIKcFi5UCGSZlXHpZ4iRag8TtQ4PDjU1&t=633185426559430639 HTTP/1.1 

Here is the response:

(Status-Line):HTTP/1.1 200 OK
Date:Thu, 28 Jun 2007 17:02:47 GMT
Server:Microsoft-IIS/6.0
X-Powered-By:ASP.NET
X-AspNet-Version:2.0.50727
Cache-Control:public
Expires:Fri, 27 Jun 2008 16:57:55 GMT
Content-Type:image/gif
Content-Length:43

The only difference I see is the "Last-Modified:Fri, 20 Apr 2007 17:04:05 GMT" header in the ScriptResource.axd response. Could this be the problem???

How on earth do I get my webresoruces to be cached? I know it's possible.

Thx, Joel

Hi Joel, did you manage to solve this problem? I've tracked both scriptresource.axd and webresource.axd via Fiddler, left debugging, traceing and viewstate (wherever possible). And still 84090k and 29530k are download everytime I refresh the page...

How are you refreshing the page? If you use Refresh (F5) Web Resources will always refresh because it overrides the Public caching. The Last-Modified indeed is a more persistent mechanism - without this header the client can't really tell when the content is out of date so the caching does a forced refresh on a browser refresh.

You should however see proper caching of Web Resources if you're just accessing pages through links or button operations.

+++ Rick ---

Uhm, it happens even when you click links...

I was thinking that this maybe happens because I placed the ScriptManager tag in a Masterpage. Is that an issue?
With Last-Modified what do you exactly mean? Is a web.config setting?

Using fiddler on my site (www.plastical.com or www.vannin.ch - these both share common settings) you notice that scriptresource.axd is always downloaded to the client (meaning a +100k page reload or refresh, whatever). I monitored other .net 2.0 sites (also asp.net forum) and it downloads the resources only once, independently of F5 or by link! There must be something wrong with my code!

Thanks for your support!

I thought you said the ScriptManager scripts are properly caching? WebResource.axd was the problem?

You have no control over the headers that ScriptManager or WebResources are generating since it's internal to ASP.NET. The only things that have an effect on it are the debug setting in web.config.

But I don't see your behavior. Everything will refresh always if you do a full f5 Refresh. Nothing refreshes if you reload the page (or another that's using the same resource) off a link.

+++ Rick ---

The problem are both, script and web resource. They return both 200 whatever I do: click on a link or full refresh the page. The same doesn't happen with forums.asp.net or any other website. I set the debug false in web.config and did the same in the General.master page (my public fron masterpage) like this:  

<asp:ScriptManager ID="SM" EnablePartialRendering="true" LoadScriptsBeforeUI="true" EnablePageMethods="false" 
ScriptMode="Release" runat="server" />

I hit my head on the table so many times to set it like this. I'm also using urlrewrite and flash (flash-control) and this was the only way to cache swf movies (setting something else would keep opening adobe's install script every time).

This is absolutely crazy: testing the pages again with fiddler (this time I checked enable gzip and hide 304) doesn't return 200 on the .axd files anymore.
Kinda weird, isn't it?
I hope this happens also for other visitors...

Thank you Rick for your great support!

PS.: You'd ask me why I'm testing performance with fiddler: well, I'm on a broadband cable network (>10Mbits) and download latencies are not perceivable with my bandwith...