IIS 7: Expires header for specific files

cachehttp-headersiis-7

I have this configuration for all static content on the site in the root directory:

<configuration>
<system.webServer>
   <staticContent>
     <clientCache cacheControlCustom="public"    cacheControlMode="UseExpires"
        httpExpires="Tue, 19 Jan 2038 03:14:07 GMT" />
  </staticContent>
</system.webServer>
</configuration>

Now I want to give a different expires header to a specific file in a subdirectory and to the favicon file in the root directory. I'm trying this configuration after the above code but I get a server error.

<location path="">
<system.webServer>
  <staticContent>
     <clientCache cacheControlCustom="public"    cacheControlMode="UseExpires"
        httpExpires="Tue, 19 Jan 2012 03:14:07 GMT" />
  </staticContent>
  </system.webServer>
</location>

Maybe can anyone help?

Best Answer

I don't think you can control the cache headers on a file level, only on a folder level. But you can always place the favicon in it's own folder and then you can control the cache control headers. If you want to support older browsers that always read the favicon from the root you can add a rewrite rule to rewrite the request to the specific folder.

To add the cache control headers on a per folder level you don't add the <location> tag but simply put a web.config file with the cache control tags in that specific folder.

Related Solutions

Varnish configuration to only cache for non-logged in users

Ok, in the end I managed to solve this using the following vcl file. Note that I added a couple of extra bits to allow cache expiration grace when the backend has died.

It seems my main failure was using unset req.http.Set-Cookie; when I should have been using unset obj.http.Set-Cookie; in the vcl_fetch section. (obj in vcl_fetch and req in vcl_recv section).

director rails_director round-robin {
  { 
    .backend = { 
      .host = "xxx.xxx.xxx.xxx"; 
      .port = "http";
      .probe = {
        .url = "/lbcheck/lbuptest";
        .timeout = 0.3 s;
        .window = 8;
        .threshold = 3;
      }
    } 
  }
}

sub vcl_recv {

  if (req.backend.healthy) {
    set req.grace = 30s;
  } else {
    set req.grace = 1h;
  }

  if (req.url ~ "^/login") {
    pipe;
  }

  if (req.url ~ "^/sessions") {
    pipe;
  }

  if (req.url ~ "\.(css|js|jpg|jpeg|gif|ico|png)\??\d*$") {
    unset req.http.cookie;
    lookup;
  } else {
    if (req.http.cookie ~ "user_credentials") {
      pipe;
    } else {
      unset req.http.cookie;
    }
  }

  # Only cache GET and HEAD requests
  if (req.request != "GET" && req.request != "HEAD") {
    pipe;
  }

}

sub vcl_fetch {

  set obj.grace = 1h;

  if (req.url ~ "^/login") {
    pass;
  }

  if (req.url ~ "^/sessions") {
    pass;
  }

  if (req.http.cookie ~ "user_credentials") {
    pass;
  } else {
    unset obj.http.Set-Cookie;
  }

  # cache CSS and JS files
  if (req.url ~ "\.(css|js|jpg|jpeg|gif|ico|png)\??\d*$") {
    unset obj.http.Set-Cookie;
  } 

  if (obj.status >=400 && obj.status <500) {
    error 404 "File not found";
  }

  if (obj.status >=500 && obj.status <600) {
    error 503 "File is Temporarily Unavailable";
  }

}

sub vcl_deliver {
  if (obj.hits > 0) {
          set resp.http.X-Cache = "HIT";
  } else {
          set resp.http.X-Cache = "MISS";
  }
}

Make IIS 7.5 cache static content files over diferent pages

When I first load "~/" of test.dev, all files will load with a response code of 200; when I press F5 in Firefox, all files, except the "~/default.aspx", will load with 304 response code; but pressing Ctrl+F5 loads them again with a 200 code; if I browse another url like "~/pages/" in test.dev, all of those static files will reload with a 200 code... Is this normal or I'm doing something wrong?

In firefox (and most other browsers) shift+F5 reloads the site ignoring the cache.

Best Answer

Related Solutions

Varnish configuration to only cache for non-logged in users

Make IIS 7.5 cache static content files over diferent pages

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