Disable static content caching in IIS 7

iis-7

I'm a developer having what should be a relatively simple problem in IIS 7 on Windows Server 2008 R2. The problem is that IIS 7 is overzealously caching all static content on the server. It's caching all .html and .js content and not noticing when the content changes on disk unless I iisreset.

I've tried the following:

Deleting the local cache in my browser (I'm 99% positive this is a server caching issue)
In IIS Admin in OutputCaching adding an .html extension and unchecking "User mode caching" and unchecking "Kernel-mode caching"
In IIS Admin in OutputCaching adding an .html extension and checking "User mode caching" and selecting the radio for "Prevent all caching"
In IIS Admin editing Output Cache Feature settings and unchecking "Enable cache" and "Enable kernel cache under OutputCaching.
Running "C:\Windows\System32\inetsrv\config\appcmd set config "SharePoint – 80" -section:
system.webServer/caching -enabled:false"
Looking through applicationHost.config and disabling anything related to caching I could find.

Nothing seems to work. I'm getting very frustrated. Can anyone please help?

Best Answer

I would really like to see system.webServer/caching section from your applicationhost.config and web.config. Please paste them if you can. By running the above appcmd command, you have just disabled User mode caching you still have Kernel caching enabled. Also, if you really want to disable caching at the Web site or server level, just change the following:

<system.webServer>
    <caching enabled="false" enableKernelCache="false" />
</system.webServer>

You can also use Fiddler tools to verify if the content is really cached i.e. if it's returning you 304.

Related Solutions

IIS 7 Backup Strategy

With IIS7, it gets MUCH easier. What you're looking for is "Shared configuration". You can set that at the global level on the server. With that, you can have hot-hot, or hot-warm like you described.

On the primary server, use "export" under shared configuration. That will save the server's Machine Key (different than ASP.NET's machineKey). That ensures that all encrypted data can be ready on the new server. It will also save applicationHost.config and administration.config. Once you do an import on the 2nd server, applicationHost.config and administration.config can (and should) be 100% the same between both servers.

So, you can use DFS-R to keep the configs 100% in sync automatically, or use something like robocopy to do it at regular intervals, depending on your favorite tool.

You don't need to point to a different path on your primary server either. Just use the export for the sake of the 2nd server.

The Web Deployment Tool is great, but for what you're talking about, Shared Configuration is a better fit.

It should be noted that certificates aren't stored in those files so you need to do them manually when you set them up, or use something else (like Web Deployment Tool) for keeping those in sync.

Another thing you can consider for an inexpensive but powerful load balancer is Microsoft's new ARR technology. (Application Request Routing)

IIS 7 returns 304 instead of 200

According to section 14.9 of the HTTP1.1 spec, the no-cache directive for the Cache-Control header is only imposable by the origin server, which means IIS is ignoring the header in your request.

The cache-control directives can be broken down into these general categories:
  - Restrictions on what are cacheable; these may only be imposed
by the origin server.

Section 14.9.1 defines public, private, and no-cache as the directives restricting what is cacheable, which can only be imposed by the server.

If you don't want your .js file to be cached you'll either need to set the no-cache directive in the app (ie- the ASP.NET code) or you'll need to change the Cache-Control header in the request to use the no-store directive instead of no-cache.

EDIT:
Based on your comment - yes I assumed you did not want the file cached. The 304, then, might be coming as a result of the file being in one of IIS's internal caches. Have a look at these:

Best Answer

Related Solutions

IIS 7 Backup Strategy

IIS 7 returns 304 instead of 200

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