In IIS, can I configure it to return different cache-control headers for different static file types in the same folder?
I'm aware that I can use the HTTP Headers feature to set Expires Immediately, but that seems to affect all content. Is there a way to do it for specific file extensions for static content?
While not an ideal answer, I did find a work-around. In my application, I have control over where my JS, CSS, and other similar files live in the directory structure. What I did was put a web.config in the IIS root directory with these lines (among others, unrelated):
<configuration>
<system.webServer>
<staticContent>
<clientCache cacheControlMode="DisableCache" setEtag="true" />
</staticContent>
</system.webServer>
</configuration>
This sets the default in IIS that nothing should be cached. This is where the HTML page (index.html) for my single-page-application (SPA) lives, so that's what I want.
Then, in immediate subdirectories for images, JS, CSS, etc, I have web.config files with the following:
<configuration>
<system.webServer>
<staticContent>
<clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="14.00:00:00" setEtag="true" />
</staticContent>
</system.webServer>
</configuration>
You can of course set the age to whatever you want. I am starting with 14 days for now until I'm sure I everything right, then I will probably bump that to several months.
This way, the HTML of my SPA will never get cached, but all the JS/CSS/images will live as long as I want. When I rebuild the project for next deployment, web-pack will generate new file names for the packed JS and CSS, so no cache problem there. The HTML file will be the same name of course, but the included JS file names will be different. So it's key that the HTML file not ever be cached, which this setup accomplishes.
IIS should really make this simpler. A cache-by-file-type config would work perfectly and not require strict directory structure management, which not all projects have the flexibility to follow.
Related
I have an that uses Twilio and this app has 2 very different sets of audio files:
Menus (files never change)
Information (files change constantly)
At the moment I had to set all the cache for my files of as I couldn't figure out how to set a different expiration date before send the file to twilio, the problem been that twilio download the files directly from the website, so as far I as understand I cannot set the cache using ASP.net
I am using the xml below in the web.config in the directory where my files are at the moment but I cannot find a way to specify different values to different files, for example:
menu1.wav - max cache
meny2.wav - max cache
info1.wav - no cache
info2.wav - no cache
Is it even possible?
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<staticContent>
<clientCache cacheControlMode="DisableCache" />
</staticContent>
</system.webServer>
</configuration>
Twilio evangelist here.
Looks like you can use the <location> element to define different folders that have different cache policys on them:
How to configure static content cache per folder and extension in IIS7?
Hope that helps.
I have a server that serves WAV file to Twilio and I am having some problems to set the cache to those files.
My problem is that the files have different expiration date, some shouldn't be cached, some should be cached for a day, some for a month and so on.
At the moment I was able to set to not cache any of the files using the IIS Output Caching, however now I need to set some caches.
Basically Twilio request the WAV files calling it directly, for example, http://mywebsite.com/mysoundwithoutcache.wav as well as http://mywebsite.com/mysoundwith1daycache.wav and so on.
My question is how do I add this headers to those files that are been called directly?
I am using IIS 7 and ASP.NET
Thanks in advance
The way to apply settings just to a certain files is to use the location tag, in your web.config add a new node under configuration:
<location path="cache_me.wav">
<system.webServer>
<caching>
<profiles>
<add extension="*.wav" policy="CacheForTimePeriod" kernelCachePolicy="DontCache" duration="01:00:00" />
</profiles>
</caching>
</system.webServer>
</location>
Unfortunately I don't think you can use wildcards in the path attribute, so you one of these sections for each file. If would be easier to put all files to be cached into a separate folder, then you can get away with a single location node.
Having said all that, you should not worry about output caching for your waves files, static files are cached by IIS automatically.
We have a website that makes use of .less files (the pre-compiler dotless has been installed using nuget), however the .less files are not handled as css files.
When trying to view the website in firefox, the console gives use the following error:
The stylesheet http:// website/css/init.less was not loaded because its MIME type, "application/octet-stream", is not "text/css".
Our dotless file is trying to import more files:
#import "imports";
..
But even replacing this text with css code, the styles are still not applied. But if I go to that file in Visual Studio, it is displaying all the css from the files that are imported.
If you're using the dotLess handler to process and serve your .less files on the fly (which is fine for debugging, but you might want to consider pre-compiling for release), you need to ensure that you also send them down with the correct mimetype.
You can do this either at the server level in IIS Admin (if you're likely to using this for multiple sites on the machine), or at the local site level via the web.config - note that you can't do both, IIS will complain that there are multiple entries for the file extension.
To do this in the web.config, within the <configuration><system.webServer> element add the following elements:
<staticContent>
<mimeMap fileExtension=".less" mimeType="text/css" />
</staticContent>
Obviously, if you've already got some mimemap entries, just add the mimemap there.
This will ensure that IIS claims that the .less files served from the handler as CSS rather than the default application/octect-stream.
If that's still not serving them as processed, there are a couple of other things you'll need to check:
Ensure that the handler is correctly registered in both the <system.webserver><handlers> and <system.web><httpHandlers> sections (depending on the version of IIS you're using:
<add name="dotless" path="*.less" verb="GET" type="dotless.Core.LessCssHttpHandler,dotless.Core" resourceType="File" preCondition="" />
and
<add path="*.less" verb="GET" type="dotless.Core.LessCssHttpHandler, dotless.Core" />
Ensure that IIS is configured to send all requests through the ASP.NET handlers configured in step 1. By default, .less files are probably being considered "static files" and will only be handled by the StaticFileModule.
According to Ultra-Fast ASP.NET: Chapter 3 - Caching:
Files that the browser retrieves from the server should be stored in
the browser’s cache as long as possible to help minimize server
round-trips.
But how does IIS know what a static content actually is and is not?
Is it just images, CSS, JS and not ASPX, ashx...?
Where can I see in IIS what is already considered to be static and what is not ?
What about the scenario where a page has been declared with <%# OutputCache header (without location)? Are the images, CSS and JS source files inside of it also being output cached with the same properties?
As a best practice, I should set one year into the future as the maximum expiration time. I should use that as the default for all static content on the site
So I did this :
But later, after pressing OK, I can't find any summary menu which shows me: to whom I already put a response header (in this case: the css folder).
Currently, in order to see that css folder has been applied with response headers - I have to go to the css folder again --> Http Response Header-->Set Common Headers --> and then I see it. It isn't written in the web.config.
But if I do it for a file (Login.aspx for example): I do see it in web.config:
<configuration>
<location path="Login.aspx">
<system.webServer>
<staticContent>
<clientCache cacheControlMode="UseExpires" cacheControlMaxAge="1.00:00:00" httpExpires="Fri, 15 Feb 2013 00:00:00 GMT" />
</staticContent>
</system.webServer>
</location>
</configuration>
I understand your situation. Sometime its confusing how IIS handles a file. Its also different for IIS 6 vs IIS 7 and different for Classic App Pools and Integrated mode app pools. My experience is mostly with Integrated App Pools on IIS 7.5, so thats the environment I can comment on most accurately.
First Question
But how does IIS knows what is actually a static content and what is
not?
Is it just images , css , js and not ASPX , ashx...?
Where can I see in the IIS what is already considered to be static and
what not ?
You can inspect the list of file handlers in IIS by navigating to your website and then click 'Handler Mappings'. By default these are inherited from the .Net base web.config which is in a different location depending on your .Net framework version.
C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG\web.config
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\web.config
If a file being requested isn't already explicitly mapped to another handler it falls to a catch all handler (*) as the last option (System.Web.DefaultHttpHandler) which determines if it is a static file or a directory browsing request. So Static files are simply files not bound to another handler already. For example you'll see that *.aspx is already mapped to System.Web.UI.PageHandlerFactory prior to this default handler. So its going to be processed by that handler and not be considered a static file. If you removed that mapping you could technically serve *.aspx as a static file if you really wanted to (just for proof of how it works).
But you can also explicitly list a file type as a static file by adding an entry in your web.config's httpHandlers section mapping the file extensions to System.Web.StaticFileHandler in IIS. For example:
<configuration>
<system.webServer>
<handlers>
<add name="StaticHandler" verb="*" path="*.zip" type="System.Web.StaticFileHandler" preCondition="integratedMode" />
</handlers>
</system.webServer>
</configuration>
This example is using the <system.webServer> config section, so its for an App Pool running in Integrated Mode.
Second Question
What about the scenario where a page has been declared with <%#
OutputCache header(without location) . does the images,css,js src
files inside of it , are also being output cached with the same
properties?
No. Because the page is being server as a separate request (maybe even by a separate handler) it can have totally different cache headers/hints. The host page and the resources it may use are not related from a caching perspective.
In fact you may even want to have a shorter cache period for *.html and a longer cache period for *.jpg or *.png? Something to consider.
Third Question
As a best prcatice , I should set one year into the future as the
maximum expiration time.I should use that as the default for all
static content on the site
Hmm... I might not go as far as one year. How about one month? I would set a global policy like this:
<configuration>
<system.webServer>
<staticContent>
<!-- Set expire headers to 30 days for static content-->
<clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="30.00:00:00" />
</staticContent>
</system.webServer>
</configuration>
This is the same as the sample you showed above, but is not inside a <location> element, instead it is right in the root <configuration> element so it is the default policy. Again this is for an App Pool running in Integrated Mode. Sometimes you also need to turn on:
<configuration>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<!-- stuff -->
</modules>
</system.webServer>
<system.webServer>
This just makes sure that static files are processed through the managed static file handler which respects the above configuration elements.
Edit to Address Comments
The documentation for the configuration dialog you posted above is located here: Configure the HTTP Expires Response Header (IIS 7)
Apparently these settings are saved in C:\Windows\System32\inetsrv\config\applicationHost.config
I do not have IIS7 and personally develop on IIS 7.5 now. So please post a comment if you can verify this location is accurate!
The static content is the one that IIS is read and send to the browser with out any processing. There you can setup IIS to include some Cache-Control Header to cache it on clients browser computers.
You can do that ether by direct setup IIS, ether by commands on web.config as you say. The commands that you add on web.config and concern the IIS, did not have to do with asp.net it self, but the IIS, and IIS saves his configuration on a different file, so when you change that cache control headers direct on IIS you do not see them on web.config.
Now for the static content like images, CSS, JavaScript, and other similar files they say that you can follow the "never expire" policy by adding 10 years expire.
The issue here is that if you can not change the content of the static file, if for example you cache a javascript file with 10 years, and you make a small change on it, then you need ether to change the file name, ether to add some parameter at the end of it.
Now the <%# OutputCache on a control is referred to the server cache and not to the client, and what is actually do is to cache the render of the control on the server so the next time you ask it to not lose time to renders it again but read it from cache - is still send it to the browser.
And you can also read this answer for some more: What are difference between IIS (Dynamic and Static) cache,OutPutCache and browser cache
I am developing a asp.net project and I dont have very long web.config file yet(more then 400 lines). but with this nhibernate log4net and urlrewrites. its getting bigger and bigger. is there a proper way to divide web.config into pieces. like nhibernate.config and log4net.config ofcourse urlrewrite.config
system.webServer is a configuration section group - you cannot externalize that.
You can only put the configSource= on a configuration section - e.g.
<system.webServer>
<validation configSource="validation.config"/>
<modules configSource="modules.config" />
<handlers configSource="handlers.config" />
</system.webServer>
What is a configuration section group or a regular configuration section can only be determined by looking at the documentation for those things (and even then it's often not very easy to figure out whether it's a section or a section group :-( ).
This is possible by using the configSource attribute of root sections in the config file. This is actually a feature of the .NET configuration system so it can be done in any web or app config file.
Here is a blog post that describes this feature quite well.